For commercial or other reasons (for example, wanting an eventual listing of the chemical on the Inventory), introducers may apply for an assessment certificate for chemical introductions meeting Exempted or Reported criteria.

Next - Section 3.2: How to categorise unlisted chemical introductions

Go back to the start Part 3 Categorisation of chemical introductions

This section describes the steps to follow to determine the introduction category for a chemical not listed on the Inventory. Later sections of this paper provide detailed descriptions of the human health and environmental criteria for each introduction category. Please note that, throughout this paper, ‘chemical’ refers to both chemicals and polymers, unless otherwise stated.

To categorise an unlisted chemical introduction, an introducer must first determine if it is of a type that delegated legislation explicitly requires to be in a particular category (Exempted, Reported or Assessed), and/or excluded from categorisation in a particular category. Examples include:

• chemical introductions via the international pathway can be categorised as Reported (see section 3.6 for further details on this pathway)
• introductions of chemicals at the nanoscale will be categorised as Assessed, except under specific circumstances (see Part 7 for further details)
• introductions of chemicals that are identified in international conventions, that Australia has ratified (such as the Stockholm Convention), will be categorised as Assessed, if their introduction is not prohibited or restricted
• introductions of chemicals comparable to chemicals on the Inventory (including polymers meeting a modified version of the “2% rule”) will be categorised as Exempted (see Attachment A for further details)
• introductions of chemicals that meet the (internationally harmonised) criteria for Polymers of Low Concern will be categorised as Exempted, except under specific circumstances. (Refer to Attachment B for PLC criteria details, including proposed changes).

If the unlisted chemical introduction is not allocated by delegated legislation to a particular category, then categorisation based on the indicative risk is undertaken. This takes into account both exposure and hazard characteristics (as represented in the risk matrices). This requires determining the introduction category for both:

• human health risks
• environmental risks.

Step 1: Determine the human health introduction category

To determine the human health introduction category, introducers must identify the:

• Exposure Band for human health
• health hazards relevant to that Exposure Band.

This information gives the human health introduction category.

Step 2: Determine the environment introduction category

To determine the environment introduction category, an introducer must identify the:

• Exposure Band for the environment
• environmental hazards relevant to that Exposure Band.

This information gives the environment introduction category.

Step 3: Determine the chemical introduction category

If the human health and environment introduction categories are the same, then the chemical introduction category is also the same.

If the human health and environment introduction categories are different, the chemical introduction category is the higher of the two. Table 3 details the outcomes.

Table 3 - Categorisation outcomes for unlisted chemical introductions

We will develop online tools prior to commencement of the new scheme to assist introducers to determine the correct introduction category.

Next - Section 3.3: Previous consultation on categorisation criteria

Go back to the start Part 3 Categorisation of chemical introductions

Earlier consultation papers for the NICNAS reforms described indicative criteria for the hazard and exposure bands for health and the environment.

We received a range of stakeholder feedback about the categorisation criteria and matrices in response to Consultation Papers 1-4. Following this feedback, further internal review of the risk-based categorisation framework has occurred.

The criteria in the following sections are the result of these considerations. They incorporate suggestions from stakeholders where these resulted in regulatory outcomes that are:

1. risk-based
2. proportionate, and
3. protective of workers, public health and the environment.

Some of these refinements of the regulatory treatment, particularly for low volume chemical introductions, have resulted in added exposure bands. Whilst this does increase the size of the visual representations (the risk matrices), there will only be one added option for the introducer to consider, and it may result in reduced regulatory burden for a significant number of introductions.

Next - Section 3.4: Criteria to determine the human health introduction category

Go back to the start Part 3 Categorisation of chemical introductions

Determining the Exposure Band for human health

The criteria to allow the relevant Exposure Band for human health to be determined are in Table 4. The introduction volume to be used when determining the Exposure Band for your introduction is the total introduction volume across all end uses. If at least one of your end uses results in intentional human exposure then the criteria applicable to  that use type applies to the total introduction volume. Definitions of key terms are included in the Defined terms section (and/or in the text below the table).

There are 4 key changes to the Hazard Band criteria since Consultation Paper 3.

We removed nanomaterials from Hazard Band D (see Part 7 for further details).

Secondly, text has been included to reflect some non-GHS hazard statements that are applicable in Australia.

Thirdly, we omitted physical hazards from Hazard Band B. We will consider associated physical hazards when assessing a chemical. However, the presence of a physical hazard will not be a basis for determining the chemical introduction category. This takes into account other legislated obligations of introducers with respect to the introduction and transport of chemicals with associated physical-chemical hazards.

Fourthly, the categorisation outcomes for polymers and chemicals with sequences of fully fluorinated carbon atoms were refined (which involved changes to the Hazard Band criteria). See Part 6 for further details. Chemicals and polymers with fully fluorinated segments have known human health concerns. This is particularly the case for longer fluorinated chain lengths. This is the reason for the placement in Hazard Band D of chain lengths between 4 and 20. Shorter chain lengths may also present some concerns. This is the reason for their placement in Hazard Band B (together with very long chain lengths that present less of a concern). These changes ensure that chemicals and polymers containing fluorinated chains of any length are Reported or Assessed, rather than Exempted.

Determining the introduction category for human health

Go back to the start of Part 3 Categorisation of chemical introductions

This part discusses:

• Determining the Exposure Band for environment
• Hazard Bands for environment
• Determining the introduction category for environment

Determining the Exposure Band for environment

^{3 Research and development does not include where release of hazardous chemicals to landfill or sewer occurs prior to treatment to render them no longer hazardous.}

In contrast to the criteria for human exposure (largely related to introduction volume), the criteria for the environment exposure largely relates to the treated release volume.

Treated release volume means the maximum volume of chemical expected to be released to the environment during the specified period:

• following some form of treatment and/or
• where treatment is not required because the chemical is released to the air in a dispersive manner from:
  • small-scale, consumer uses, including (but not limited to) aerosols
  • end use of volatile substances, where the release is incidental.

Treatment means some form of intervention (including capture, destruction, irreversible transformation or disposal to landfill) to minimise release of a chemical into the environment.

The treated release volume is estimated as a percentage of the maximum introduction volume expected to be released. It relies on the use of release factors. Further discussion on our approach to developing default release factors, for use when determining the Exposure Band for environment, is included in the Consultation Paper 5 Supporting Material.

Release without treatment would fall into the highest Exposure Band. Examples of appropriate treatment of chemicals and releases without treatment are provided in Table 8.

There are 3 key changes to the Exposure Band criteria since Consultation Paper 3.

Firstly, there was a change in terminology to refer to ‘treated release volume’, which is more explicit and allows for dispersive releases to air (which are untreated, but not of concern) to be captured in lower Exposure Bands.

Secondly, a low volume threshold exposure band (Exposure Band 2) was added to decrease the regulatory burden associated with introduced chemicals (excluding those of highest concern) with very low treated release volumes (≤10 kg/annum).

Thirdly, the ‘irreversibly bound within an inert matrix’ criterion in Exposure Band 5 was removed. Chemicals bound within an inert matrix will be considered in the development of default environmental release factors. Thus, the introductions of such chemicals should be categorised similarly to other introduced chemicals.

Hazard Bands for environment

The Hazard Bands depicting the possible hazard characteristics of chemicals for environment (and/or uncertainties with respect to hazards for environment) are in Table 9. Hazard Band E includes hazard characteristics of highest concern to the environment and characteristics with greatest uncertainty with respect to concern to or effects on, the environment. How the introducer demonstrates hazard characteristics will vary depending on the Exposure Band (the information requirements will vary based on the anticipated release to the environment; see Part 5 for further details).

^{4 See Attachment C for national PBT criteria and/or Defined terms for further details on criteria. Note that while based on the GHS toxicity criteria, the term ‘Toxic’ in this instance relates to a specific threshold used for the purposes of defining PBT in Australia.}

The PBT criteria in the delegated legislation will align with the national PBT criteria as set out in Attachment C – Persistent bioaccumulative and toxic substances (PBT) Criteria.

There are 4 key changes to the Hazard Band criteria since Consultation Paper 3:

1. we removed nanomaterials from Hazard Band E (see Part 7 for further details)
2. we added synthetic greenhouse gas chemicals to Hazard Band E
3. we refined the Hazard Band B criteria for polymers and inorganic chemicals
4. we refined and clarified the categorisation outcomes for polymers and chemicals containing sequences of fully fluorinated carbon atoms (which involved changes to the Hazard Band criteria). See Part 6 for further details.

Chemicals and polymers with fully fluorinated segments have the potential to degrade to chemicals that may be persistent in the environment, may bioaccumulate, and may be highly toxic. Longer fluorinated chain lengths are of greater concern. This is the reason for the placement in Hazard Band E of chain lengths between 4 and 20. Shorter chain lengths may also present some concerns. This is the reason for their placement in Hazard Band D (together with very long chain lengths that present less of a concern). These changes ensure that chemicals and polymers containing fluorinated chains of any length are Reported or Assessed, rather than Exempted.

Determining the introduction category for environment

The combination of Exposure Band and environment hazards gives the environment introduction category. Figure 4 outlines the way exposure and hazard bands interact to determine the relevant introduction category for environment:

If a chemical introduction is in Exposure Band 1 for environment, the chemical introduction category will be Exempted for environment. This is irrespective of the hazard characteristics of the chemical.

If a chemical introduction is in Exposure Band 2 for environment, the chemical introduction category will be:

• Exempted for environment if the chemical does not have the hazard characteristics described in Hazard Band D or E or
• Reported for environment if the chemical does not have the hazard characteristics described in Hazard Band E
• Assessed for environment in all other circumstances.

If a chemical introduction is in Exposure Band 3 or 4 for environment, the chemical introduction category will be:

• Exempted for environment if the chemical does not have the hazard characteristics described in Hazard Band C, D or E or
• Reported for environment if the chemical does not have the hazard characteristics described in Hazard Band E or
• Assessed for environment in all other circumstances.

If a chemical introduction is in Exposure Band 5 for environment, the chemical introduction category will be:

• Exempted for environment if the chemical does not have the hazard characteristics described in Hazard Band B, C, D or E or
• Reported for environment if the chemical does not have the hazard characteristics described in Hazard Band D or E or
• Assessed for environment in all other circumstances.

If a chemical introduction is in Exposure Band 6 for environment, the chemical introduction category will be:

• Exempted for environment if the chemical does not have the hazard characteristics described in Hazard Band B, C, D or E or
• Reported for environment if the chemical does not have the hazard characteristics described in Hazard Band C, D or E or
• Assessed for environment in all other circumstances.

Note that while the regulatory outcomes for Exposure Bands 3 and 4 are the same, the information requirements to characterise the hazards for these two exposure bands are different (see Part 5 for further details).

Table 10 presents an alternate way to consider the above, focusing on the category outcome.

Next - Section 3.6: Criteria for categorisation as Reported using international pathways

Go back to the start Part 3 Categorisation of chemical introductions

Reported chemical introductions can include the introduction of potentially higher risk chemicals (that would otherwise be categorised as Assessed) using the international pathway. Such chemicals must have had a risk assessment or evaluation undertaken by, or in association with, a trusted prescribed international body (refer to the following section). There are also further criteria relating to the risk assessment and its outcomes, as detailed below.

Trusted prescribed international bodies for the international pathway

Table 11 lists the trusted prescribed international bodies. These bodies have been assessed as meeting the Health portfolio regulators criteria for the adoption of international standards and risk assessments⁵ (i.e. the criteria to be a trusted prescribed international body for the international pathway). They will be prescribed in delegated legislation.

^{5 http://www.health.gov.au/internet/main/publishing.nsf/Content/RPF-International-stds}

Additional international bodies may be added to the delegated legislation later if they meet the criteria to be a trusted prescribed international body for the international pathway.

Stakeholder feedback from previous consultation papers suggested other international bodies that could be trusted prescribed bodies for the international pathway. At this time, no other international bodies meet the relevant criteria.

The acceptability of assessments undertaken through the Frank R. Lautenberg Chemical Safety for the 21st Century Act (i.e. the amended Toxic Substances Control Act of the US EPA) for the international pathway is uncertain at this time. This is because it is still early in the implementation of these amendments and there have been relatively few assessments undertaken and published. We will consider this further after we know more about the implementation of the amended US legislation and the assessments being undertaken under it. Note that parallel process assessments are the exception to this, as mentioned in Table 11.

Further requirements for use of the international pathway

For use of this pathway, the international risk assessment/evaluation performed by a trusted international prescribed body must:

• take into account both hazard and exposure, and the chemical must have been assessed for both health and environmental risks (not necessarily by the same trusted international prescribed body) unless
  • the international risk assessment is for human health risks only, and the chemical is categorised as Exempted or Reported for environment
  • the international risk assessment is for environmental risks only, and the chemical is categorised as Exempted or Reported for human health.

• be for the same end use as the proposed chemical introduction into Australia
• be for the same or higher introduction volume compared  to the proposed chemical introduction into Australia
• be for the same or higher use concentration compared to the proposed chemical introduction into Australia.

The risk of introduction into Australia must be no higher than that identified in the overseas jurisdiction. This must take into account:

• the risk assessment assumptions applied by the international regulator and the relevance to the Australian context
• any risk management conditions from the international risk assessment that must be able to be met in Australia
• any information that has become available since the overseas assessment/approval.

The international pathway does not provide a route to listing on the Inventory. This is consistent with the fact that other chemicals in this category (Reported chemical introductions) will not be entered on the Inventory.

We would review the information reported by introducers in reliance on the international pathway and, if necessary, make recommendations to risk managers.

If we determine that the criteria have not been met, and the chemical introduction properly requires assessment, the introducer would need to comply with the requirements of the Assessed category in order to continue to introduce the chemical.

Next - Part 4: Information requirements for categorisation and assessment of unlisted chemicals

Go back to the start of Part 4 Information requirements for categorisation and assessment of unlisted chemicals

Exempted introductions do not need pre-introduction reporting or assessment. The introducer must still maintain and provide records, on request, for an introduced chemical’s identity and the basis on which the categorisation was determined (i.e. information on the exposure and hazard characterisation).

Chemical identity

Required information related to chemical identity:

• proper chemical name, i.e. CAS name and/or IUPAC name
• CAS registry number (if available)
• common or trade name (if available)
• synonyms (if available), and
• as complete a description as possible if the chemical is a UVCB (e.g. CAS description, details of the immediate precursors/natural sources).

If your chemical is a polymer, in addition to the above, you will also need:

• identity of all polymer constituents that are present at >2% (by weight) prior to polymerisation
• molecular weight distribution of the polymer:
  • number average molecular weight (NAMW)
  • weight average molecular weight (WAMW)
• polydispersity index (WAMW/NAMW)
• the percentage of low molecular weight oligomeric species:
  • below 1,000 Daltons, and
  • below 500 Daltons.

Exposure characterisation

Required information related to exposure characterisation:

• the Exposure Bands for human health and the environment
• annual introduction volume
• use of the chemical (including end-uses and likely end-of-life disposal pathways)
• calculated release volume.

Hazard characterisation

Required information related to the hazard characterisation:

• the minimum information requirements for categorisation (as applicable for the Exposure Band) and
• the additional information used to categorise as Exempted (if applicable).

Next - Section 4.2: Reported introductions

Go back to the start of Part 4 Information requirements for categorisation and assessment of unlisted chemicals

As with Exempted introductions, introducers must maintain and be able to provide records of the chemical identity of the introduced chemical and be able to support the categorisation decision (i.e. have information on the exposure and hazard characterisation).

Introducers will also have to submit information via the online portal before they introduce the chemical. A third party can do this if the information is confidential from the introducer.

Information submitted prior to introduction will aid in targeted post-introduction monitoring efforts. As there will be a reduction in pre-introduction assessments by us (of lower risk chemical introductions), there will be more post-introduction monitoring to ensure human health and environmental protections are maintained.

The report submitted to us prior to introduction will include the following items.

Chemical identity

Required information related to chemical identity:

• proper chemical name, i.e. CAS name and/or IUPAC name
• CAS registry number (if available)
• common or trade name (if available)
• synonyms (if available)
• as complete a description as possible if the chemical is a UVCB (e.g. CAS description, details of the immediate precursors/natural sources)

If your chemical is a polymer, in addition to the above, you will also need:

• identity of all polymer constituents that are present at >2% (by weight) prior to polymerisation
• molecular weight distribution of the polymer:
  • number average molecular weight (NAMW)
  • weight average molecular weight (WAMW)
  • polydispersity index (WAMW/NAMW)
• the percentage of low molecular weight oligomeric species:
  • below 1,000 Daltons, and
  • below 500 Daltons.

Identification of the type of Reported introduction

Introducers would select from a list such as:

• chemical introduction categorised as Reported based on the relevant Exposure and Hazard Band criteria
• chemical introduction categorised as Exempted but chosen by introducer to report
• introduction via the international pathway of a chemical otherwise categorised as an Assessed introduction.

Exposure characterisation of the chemical introduction

Required information related to exposure characterisation:

• the Exposure Bands for human health and the environment
• volume:
  • annual introduction volume (within defined bands)
  • release volume (using default release factors)
• concentration – maximum introduction and end use concentrations (within defined bands)
• end use (using high-level use descriptors)
• confirmation that any relevant Exposure Band criteria are met (tick-box style; e.g. treatment prior to release, criteria related to research and development).

Hazard characterisation of the chemical

Required information related to the hazard characterisation:

• the Hazard Bands of the chemical for human health and the environment
• the known hazard classification
• confirmation that the minimum information requirements for categorisation (if applicable for the Exposure Band) have been met
• if the applicable Hazard Band was based on structural considerations (e.g. chemicals that contain a sequence of ≤3 or ≥21 fully fluorinated carbon atoms) and/or uncertainties associated with the hazard characteristics.

International pathway information

• The name of the trusted international prescribed body that undertook the assessment/evaluation
• the scope of the assessment/evaluation (including use, volume and concentration)
• confirmation that the risk of introduction into Australia is no higher than that identified in the overseas jurisdiction, taking into account the risk assessment assumptions applied by the international regulator
• the date of the assessment
• the assessment reference and permission from the original overseas notifier to allow us access to any unpublished assessment reports held by the overseas body
• information about any conditions recommended as part of the assessment or that formed part of any subsequent regulatory approval by the relevant body, and a statement describing how those conditions would be met by the introducer in Australia
• confirmation the introducer is not aware of any new information, since the international assessment/approval, that adversely affects the hazard profile of the chemical.

Next - Section 4.3: Assessed introductions

Go back to the start of Part 4 Information requirements for categorisation and assessment of unlisted chemicals

For Assessed introductions, introducers must submit information to us for a risk assessment and be given an assessment certificate before introducing a chemical. Third parties can submit information if it is confidential from the introducer. The risk assessment will focus on issues of particular concern to human health and/or the environment.

The information needed to support an application for assessment will be set out in delegated legislation. Further details will be set out in the Characterisation Guide (and associated guidance materials) and on the approved application form.

Some general comments on required information are included in Table 12 in question and answer style. We provide more detail on the requirements below the table.

Chemical identity

Required information related to chemical identity:

• proper chemical name, i.e. CAS name and/or IUPAC name
• CAS number (if available)
• proposed AICIS approved chemical name (AACN, if relevant)
• common name/trade name/marketing name
• synonyms (if available, e.g. chemical identifiers in study reports)
• molecular formula (if defined)
• structural formula (if defined)
• molecular weight or weight range (if defined)
• composition (e.g. purity, identity of impurities, reactants, and additives/adjuvants), identity and ratio of component chemicals as far as is known if a UVCB, and if such composition changes batch-to-batch)
• analytical information (enough information sufficiently characterise the chemical) and
• as complete a description as possible if the chemical is a UVCB (e.g. CAS description, details of the immediate precursors/natural sources).

If your chemical is a polymer, in addition to the above, you will also need:

• identity and percentage of all polymer constituents prior to polymerisation
• the percentage residual of each constituent remaining (by weight) following completion of the polymerisation
• molecular weight distribution of the polymer:
  • number average molecular weight (NAMW)
  • weight average molecular weight (WAMW)
  • polydispersity index (WAMW/NAMW)
• the percentage of low molecular weight oligomeric species:
  • below 1,000 Daltons, and
  • below 500 Daltons.

Physico-chemical properties

Required information related to physico-chemical properties:

• melting point/freezing point
• boiling point
• density
• vapour pressure
• water solubility
• hydrolysis as a function of pH
• partition coefficient (n-octanol/water)
• adsorption and desorption
• dissociation constant
• particle size (distribution)/fibre length (for solids only)
• flashpoint
• flammability limits
• auto-ignition temperature
• explosive properties, and
• reactivity (oxidising properties, conditions causing instability, decomposition products).

General introduction information

Required general introduction information:

• mode of introduction (import or manufacture)
• introduction volume of the chemical for each of the first five years
• proposed end use(s) for the chemical, and proportion of the introduction volume expected to be associated with each end use sector
• proposed Safety Data Sheet and labels, and
• details of any known assessments of the chemical by other national or international regulatory agencies (e.g. agency and year).

Exposure and release information

Required exposure and release information:

• the manufacture and reformulation processes
• details relevant to worker exposure (e.g. who will handle the chemical and in what form/concentration; any controls, including engineering, PPE and administrative, that will be in place to prevent exposure to the chemical)
• whether members of the public will handle the chemical or products containing the chemical, and if so, in what form and concentration, and
• details relevant to environmental exposure (e.g. sites of manufacture/reformulation and end use, anticipated environmental release/disposal methods at the end of the chemical’s useful life).

Hazard and fate information:

Required hazard and fate information:

• human health hazard information requirements, generally consistent with the minimum requirements identified in Part 5 and Part 6, and any other hazard information available to the introducer
• environmental hazard and fate information requirements to address:
  • persistence in the environment (e.g. biodegradability data)
  • bioaccumulation potential (partition coefficient or bioaccumulation factor data)
  • toxicity to organisms (e.g. data for fish, invertebrates and algae).

Next - Part 5: Categorising an unlisted chemical introduction - hazard information requirements

Go back to the start of Part 5 Categorising an unlisted chemical introduction - hazard information requirements

We outline the hazard characteristics for human health that you must address (per Exposure Band) in this section. Details include:

• the minimum information requirements to categorise a chemical
• the information required if you want to demonstrate that a chemical or low molecular weight polymer is not hazardous to human health (and can be categorised as an Exempted introduction).

The reason additional information is required for categorising as Exempted for most Exposure Bands is because there will be no pre-introduction interactions with us for Exempted introductions (and we will not be advised of the chemical details). Thus, the introducer must have the information that shows the chemical is not hazardous to human health.

The information requirements do not necessarily address all Hazard Band criteria. In some cases, the chemical would only be in the Hazard Band:

1. based on structural considerations and uncertainties associated with the hazard characteristics
2. because the chemical was already known to have that hazard
3. if the hazard characteristic was noted while addressing other specified requirements (e.g. specific target organ toxicity (single exposure) effects evident when addressing the requirements for acute toxicity).

The minimum information requirements to categorise a high molecular weight polymer are based mainly on structural considerations. In most cases, it will not be necessary to hold or generate human health hazard information on these polymers. However, if such information already exists, it should be used when determining the appropriate hazard band for the polymer.

For the minimum information requirements, Table 14 provides a summary of the hazard characteristics that must be addressed for each Exposure Band for chemicals and for low molecular weight polymers. Detailed discussion follows the table. For the actual information requirements to address each hazard characteristic, see Consultation Paper 5 Supporting Material.

^{6 The specified lists will be publicly available. Refer to Section 3 of Consultation Paper 5 Supporting Material for further information.}

Exposure Band 1 (chemicals and polymers)

There will be no information requirements when categorising the chemical introduction for human health for this Exposure Band. This is because the very low indicative risk for these chemicals is based on the very low expected human exposure.

Exposure Band 2 (chemicals and polymers)

The minimum information requirements will be a determination of whether the chemical is known to be any of the following based on specified lists and existing information:

• carcinogenic
• mutagenic/genotoxic
• a reproductive or developmental toxicant
• a chemical with adverse effects known to be mediated by an endocrine disruption mode of action.

Further information on how an introducer shows this for chemicals and polymers with NAMW ≤1,000 Da is included in Consultation Paper 5 Supporting Material. If the chemical is identified as having these hazard characteristics (and/or uncertainties with respect to hazard characteristics), it falls under Hazard Band D.

If the chemical falls under Hazard Band D, the introduction will be categorised as Assessed for human health. If it does not fall under Hazard Band D, because it does not have any of the above characteristics, the introduction may be categorised as Exempted for human health.

Exposure Band 3

Exposure Band 3 (chemicals and low molecular weight polymer)

Like Exposure Band 2, the minimum information requirements will be a determination of whether the chemical is known to be any of the following based on specified lists and existing information:

• carcinogenic
• mutagenic/genotoxic
• a reproductive or developmental toxicant
• a chemical with adverse effects known to be mediated by an endocrine disruption mode of action.

If the chemical falls under Hazard Band D, the introduction will be categorised as Assessed for human health. If it does not fall under Hazard Band D, because it does not have any of the above characteristics, the introduction may be categorised as Reported for human health.

Exposure Band 3 (optional) – additional requirements to demonstrate that a chemical or a low molecular weight polymer is not hazardous

For introductions to be categorised as Exempted it will be necessary to show that the chemical does not have the characteristics described in Hazard Bands B, C, and D. Additional information requirements apply to address these hazard characteristics:

• mutagenicity/genotoxicity (information additional to checking of specified lists)
• acute toxicity (oral, or whichever exposure route is most relevant)
• specific target organ toxicity (repeated exposure)
• skin and eye damage/irritation
• skin sensitisation.

Exposure Band 3 (high molecular weight polymer)

The Minimum information requirements will be:

• a determination of whether the polymer is known to be any of the following based on specified lists and existing information:
  • carcinogenic
  • mutagenic/genotoxic
  • a reproductive or developmental toxicant
  • a chemical with adverse effects known to be mediated by an endocrine disruption mode of action.
  • consideration of any existing hazard information on the polymer
  • consideration of the other hazard band criteria relevant to polymers

If the polymer falls under Hazard Band D, the introduction will be categorised as Assessed for human health. If the polymer does not fall under Hazard Band D, the introduction may be categorised as Reported for human health.

Exposure Band 3 (optional) – additional requirements to demonstrate that a high molecular weight polymer is not hazardous

Additional considerations for polymers with NAMW ≥1,000 Da may result in the polymer introduction being categorised as Exempted. This could involve consideration of:

• the PLC criteria – if the polymer meets the PLC criteria, it will be categorised as Exempted, except under specific circumstances (see Part 3).
• any existing hazard information on the polymer that could rule out hazards in Hazard Bands B or C.
• the minimum information (on the polymer itself or a suitable analogue) required to demonstrate that a polymer is not hazardous is:
  • acute toxicity by a relevant route of exposure
  • skin irritation
  • eye irritation
  • mutagenicity/genotoxicity – bacterial reverse mutation.

If the polymer contains one or more high concern RFGs with a functional group equivalent weight <5,000, as defined in the PLC criteria, you are also required to have information on skin sensitisation potential. This does not apply to un-substituted positions ortho and para to phenolic hydroxyl or partially-hydrolysed acrylamides.

All such information should indicate that the polymer is not hazardous.

Exposure Band 4 (chemicals and low molecular weight polymer)

Minimum information requirements will apply to address the following hazard characteristics:

• carcinogenicity (if known)
• reproductive or developmental toxicity (if known)
• adverse effects known to be mediated by an endocrine disruption mode of action (if known)
• mutagenicity/genotoxicity
• acute toxicity (oral, or whichever other exposure route is most relevant)
• skin corrosion and eye damage
• skin sensitisation.

If the chemical falls under Hazard Band C or D, the introduction will be categorised as Assessed for human health. If it does not fall under Hazard Band C or D, the introduction may be categorised as Reported for human health.

As previously indicated, the information requirements do not necessarily address all Hazard Band criteria. An example of this is specific target organ toxicity (repeated exposure), which is included in Hazard Band C. Information on toxicity after repeated exposure is not a requirement for chemical introductions in Exposure Band 4 to be categorised as Reported. If such information is available however, it should be considered to determine whether the chemical should be placed in Hazard Band C.

Exposure Band 4 (optional) – additional requirements to demonstrate that a chemical or a low molecular weight polymer is not hazardous

For introductions to be categorised as Exempted, it will be necessary to have information to show that the chemical does not have the characteristics described in Hazard Bands B, C, and D. Additional information requirements apply to address these hazard characteristics:

• specific target organ toxicity (repeated exposure)
• skin and eye irritation.

Exposure Bands 4 – 5 (high molecular weight polymer)

The minimum information requirements will be:

• a determination of whether the polymer is known to be any of the following based on specified lists and existing information:
  • carcinogenic
  • mutagenic/genotoxic
  • a reproductive or developmental toxicant
  • a chemical with adverse effects known to be mediated by an endocrine disruption mode of action.
• consideration of any existing hazard information on the polymer
• consideration of the other hazard band criteria relevant to polymers

If the polymer falls under Hazard Band D, the introduction will be categorised as Assessed for human health. If the polymer does not fall under Hazard Band D, it may fall into Hazard Band B or C, and its introduction categorised as Reported or Assessed for human health.

Exposure Bands 4 and 5 (optional) – additional requirements to demonstrate that a high molecular weight polymer is not hazardous

Additional considerations for polymers with NAMW ≥1,000 Da may result in the polymer introduction being categorised as Exempted. This could involve consideration of:

• the PLC criteria - if the polymer meets the PLC criteria, it will be categorised as Exempted, except under specific circumstances (see Part 3)
• any existing hazard information on the polymer that could rule out hazards in Hazard Bands B or C
• the minimum information (on the polymer itself or a suitable analogue) required to demonstrate that a polymer is not hazardous is:
  • acute toxicity by a relevant route of exposure
  • skin irritation
  • eye irritation
  • mutagenicity/genotoxicity – bacterial reverse mutation.

If the polymer contains one or more high concern RFGs with a functional group equivalent weight <5,000 Da, as defined in the PLC criteria, you are also required to have information on skin sensitisation potential. This does not apply to un-substituted positions ortho and para to phenolic hydroxyl or partially-hydrolysed acrylamides.

All such information should indicate that the polymer is not hazardous.

Exposure Band 5 (chemicals and low molecular weight polymers)

Minimum information requirements will apply to address the following hazard characteristics:

• carcinogenicity (if known)
• reproductive or developmental toxicity (if known)
• adverse effects known to be mediated by an endocrine disruption mode of action (if known)
• mutagenicity/genotoxicity
• acute toxicity (oral, or whichever other exposure route is most relevant)
• specific target organ toxicity (repeated exposure)
• skin corrosion/irritation and eye damage/irritation
• skin sensitisation.

If the chemical falls under Hazard Band C or D, the introduction will be categorised as Assessed for human health. If it does not fall under Hazard Band C or D, the introduction may be categorised as Reported for human health.

In this Exposure Band, the same information requirements apply when categorising the introduction for human health and when demonstrating that a chemical is not hazardous. This greater level of information to characterise the hazards is commensurate with the potential for increased exposure in this highest Exposure Band.

Options to demonstrate that a chemical is not hazardous to human health

To characterise chemicals (and low molecular weight polymers) in Exposure Bands 3-5 as non-hazardous, it is necessary to show the chemical does not have the hazard characteristics associated with Hazard Bands B-D. Consultation Paper 5 Supporting Material provides further details on information requirements to address each hazard characteristic.

A summary of the types of information you can provide to show that a chemical is not hazardous is included in Table 15. Where possible, options are provided that take into account in silico, in chemico, in vitro and in vivo information sources, with the level of information required commensurate with the predicted level of exposure.

^{7 Combination of in silico and in chemico/in vitro required.}

^{8 Level of information required (e.g. existing published information vs test report) depends on hazard characteristic and Exposure Band.}

^{# For categorisation, an available in vivo test result is an acceptable option in all circumstances to meet the information requirements to demonstrate the chemical is not genotoxic or mutagenic. Generation of new in vivo information is only required under certain circumstances e.g. to meet information requirements for Assessed chemicals, where an in vitro assay has predicted a positive mechanism an in vivo study addressing that mechanism is required.}

Next - Section 5.3: Information requirements to determine the environment introduction category

Exposure Band 1

There will be no information requirements when categorising the chemical introduction for environment for this Exposure Band. This is because the very low indicative risk for these chemicals is based on the very low expected environmental exposure.

Exposure Band 2

The minimum information requirement will be a determination of whether the chemical is known to be any of the following (characteristics found in Hazard Band E) based on specified lists and existing information:

• Persistent, Bioaccumulative and Toxic (PBT, according to the national PBT criteria)
• ozone depleting
• a chemical that contains a sequence of ≥4 and ≤20 fully fluorinated carbon atoms
• a chemical that contains high concern inorganic elements (mercury, lead, cadmium, and arsenic)
• a chemical with adverse effects known to be mediated by an endocrine disruption mode of action.

If the chemical has any of these characteristics, it falls under Hazard Band E and the introduction will be categorised as Assessed for environment. If the chemical is not known to have any of these characteristics then it will be categorised as Reported for environment.

Exposure Band 2 – requirements to categorise as Exempted

For introductions to be categorised as Exempted it will be necessary to know that the chemical does not have any of the following (characteristics described in Hazard Band D) based on specified lists and existing information:

• very toxic to aquatic organisms or
• Persistent and Bioaccumulative (PB).

Exposure Band 3

The minimum information requirements will be a determination of whether or not the chemical is known to be any of the following based on specified lists and existing information:

• Persistent, Bioaccumulative and Toxic (PBT, according to the national PBT criteria)
• ozone depleting
• a chemical that contains a sequence of ≥4 and ≤20 fully fluorinated carbon atoms
• a chemical that contains high concern inorganic elements (mercury, lead, cadmium and arsenic)
• a chemical with adverse effects known to be mediated by an endocrine disruption mode of action.

If the chemical has any of these characteristics, it falls under Hazard Band E and the introduction will be categorised as Assessed for environment. If it does not have any of the above characteristics, the introduction may be categorised as Reported for environment.

Exposure Band 3 (optional) – additional requirements to categorise as Exempted

For introductions to be categorised as Exempted it will be necessary to show that the chemical does not have the characteristics described in Hazard Bands C, D, and E. In addition to the compulsory considerations, the chemical must not have any of the following additional hazard characteristics (that are found in Hazard Band D and C):

• toxic to aquatic organisms
• Persistent and Bioaccumulative (PB).

To show that the chemical does not possess these characteristics the following minimum information would be needed:

• Acute aquatic toxicity for the three trophic levels (fish, invertebrates and algae)
• at least one of the following:
  • persistence information: biodegradation (ready or inherent)
  • bioaccumulation information: partition coefficient (log Kow) or bioaccumulation (BAF / BCF).

However, if either the persistence or bioaccumulation information indicates a P or B result, the other test is needed to show if the chemical is PB.

Exposure Band 4

The first step in characterising the hazard for chemicals in these exposure bands is determining if the chemical is already known (based on specified lists and existing information) to have any of the characteristics in Hazard Band E, that is:

• Persistent, Bioaccumulative and Toxic (PBT, according to the national PBT criteria)
• ozone depleting
• a chemical that contains a sequence of ≥4 and ≤20 fully fluorinated carbon atoms
• high concern inorganic elements (mercury, lead, cadmium, and arsenic)
• a chemical with adverse effects known to be mediated by an endocrine disruption mode of action.

If the chemical is identified as having any of these characteristics it falls under Hazard Band E and the introduction will be categorised as Assessed for environment.

If the above information is not available (i.e. the chemical is not found on specified lists or there is no existing information available), then at least one of the following minimum information requirements will be needed to characterise the hazards of the chemical to determine if it has PBT characteristics:

• acute aquatic toxicity for the three trophic levels (fish, invertebrates and algae)
• persistence information: biodegradability (ready or inherent)
• bioaccumulation potential: partition coefficient (logKow) or bioaccumulation (BAF/BCF).

If the toxicity, persistence or bioaccumulation information indicates a T or P or B result, the other tests may be required to show if the chemical is PBT.

Depending on the hazard characterisation arising from this information, the chemical introduction may be categorised as either Assessed or not Assessed (default to Reported) for the environment.

Exposure Band 4 (optional) – additional requirements to categorise as Exempted

As for Exposure Band 3, for introductions to be categorised as Exempted it will be necessary to show that the chemical does not have the characteristics described in Hazard Bands C, D and E. In addition to the compulsory considerations, the chemical must not have any of the following additional hazard characteristics (that are found in Hazard Band D and C):

• toxic to aquatic organisms (according to the GHS)
• Persistent and Bioaccumulative (PB)
• fully fluorinated carbon atoms in a sequence of ≤3 or ≥21.

To show that the chemical does not possess these characteristics the following minimum information would be needed:

• acute aquatic toxicity for the three trophic levels (fish, invertebrates and algae)
• information to indicate if the chemical has fully fluorinated carbon atoms in a sequence of ≤3 or ≥21.
• At least one of the following:
  • persistence information: biodegradation (ready or inherent)
  • bioaccumulation potential: partition coefficient (log Kow) or bioaccumulation (BAF / BCF).

However, if either the persistence or bioaccumulation information indicates a P or B result, the other test is needed to show if the chemical is PB.

Exposure Band 5

The first step in characterising the hazard for chemicals in these exposure bands is determining if the chemical is already known (based on specified lists and existing information) to have any of the characteristics in Hazard Band E, that is:

• Persistent, Bioaccumulative and Toxic (PBT, according to the national PBT criteria)
• a chemical with adverse effects known to be mediated by an endocrine disruption mode of action
• ozone depleting
• a chemical that contains a sequence of ≥4 and ≤20 fully fluorinated carbon atoms
• high concern inorganic elements (mercury, lead, cadmium, and arsenic).

If the chemical is identified as having any of these characteristics it falls under Hazard Band E and the introduction will be categorised as Assessed for environment.

If the chemical does not fall under Hazard Band E then the following minimum information will be needed to characterise the hazards of the chemical to determine if it meets the criteria for Hazard Band D:

• acute aquatic toxicity for the three trophic levels (fish, invertebrates and algae)
• information to indicate if the chemical has fully fluorinated carbon atoms in a sequence of ≤3 or ≥21
• at least one of the following:
  • persistence information: biodegradability (ready or inherent)
  • bioaccumulation potential: partition coefficient (log Kow) or bioaccumulation (BAF/BCF).

However, if either the persistence or bioaccumulation information indicates a P or B result, the other test is required to show if the chemical is PB.

Depending on the hazard characterisation arising from this information, the chemical introduction may be categorised as either Assessed or not Assessed (default to Reported) for the environment.

Exposure Band 5 (optional) – additional requirements to categorise as Exempted

For introductions to be categorised as Exempted it will be necessary to show that the chemical does not have the characteristics described in Hazard Bands B, C, D and E. In addition to the compulsory considerations, the chemical must not have any of the following additional hazard characteristics (that are found in Hazard Band B and C):

• Bioaccumulative
• not readily biodegradable
• contain copper, nickel, zinc, silver, chromium or aluminium
• polymers that have an overall cationic charge at pH 4-9
• polymers that are not stable (unless a biopolymer).

To show that the chemical does not possess these characteristics the following additional minimum information would be needed:

• Both of:
  • persistence information: biodegradation (ready or inherent)
  • bioaccumulation potential: partition coefficient (log Kow) or bioaccumulation (BAF / BCF).

Exposure Band 6

The first step in characterising the hazard for chemicals in these exposure bands is determining if the chemical is already known (based on specified lists and existing information) to have any of the characteristics in Hazard Band E, that is:

• Persistent, Bioaccumulative and Toxic (PBT, according to the national PBT criteria)
• ozone depleting
• a chemical that contains a sequence of ≥4 and ≤20 fully fluorinated carbon atoms
• high concern inorganic elements (mercury, lead, cadmium, and arsenic)
• a chemical with adverse effects known to be mediated by an endocrine disruption mode of action.

If the chemical is identified as having any of these characteristics it falls under Hazard Band E and the introduction will be categorised as Assessed for environment.

If the chemical does not fall under Hazard Band E then the following minimum information will be needed to characterise the hazards of the chemical to determine if it meets the criteria for Hazard Band C or D:

• acute aquatic toxicity for the three trophic levels (fish, invertebrates and algae)
• information to indicate if the chemical has fully fluorinated carbon atoms in a sequence of ≤3 or ≥21
• at least one of the following:
  • persistence information: biodegradability (ready or inherent)
  • bioaccumulation potential: partition coefficient (log Kow) or bioaccumulation (BAF/BCF).

However, if either the persistence or bioaccumulation information indicates a P or B result, the other test is required to show if the chemical is PB.

Depending on the hazard characterisation arising from this information, the chemical introduction may be categorised as either Assessed or not Assessed (default to Reported) for the environment.

Exposure Band 6 (optional) – additional requirements to categorise as Exempted

These requirements will be the same as for the optional requirements under Exposure Band 5. For introductions to be categorised as Exempted it will be necessary to show that the chemical does not have the characteristics described in Hazard Bands B, C, D and E. In addition to the compulsory considerations, the chemical must not have any of the following additional hazard characteristics (that are found in Hazard Band B and C):

• Bioaccumulative
• not readily biodegradable
• contain copper, nickel, zinc, silver, chromium or aluminium
• polymers that have an overall cationic charge at pH 4-9
• polymers that are not stable  (unless a biopolymer).

To show that the chemical does not possess these characteristics the following additional minimum information would be needed:

• Both of:
  • persistence information: biodegradation (ready or inherent); and
  • bioaccumulation potential: partition coefficient (log Kow) or bioaccumulation (BAF / BCF).

Next - Part 6: Specified chemical introductions - additional requirements

Go back to the start of Part 7 Regulatory treatment of unlisted chemicals introduced at the nanoscale

Categorisation outcomes

In order to refine their regulatory treatment and focus on the chemicals of most concern, it is proposed that introductions of unlisted chemicals consisting of particles at the nanoscale will not be categorised using the same hazard and exposure band criteria proposed for other chemicals.

Instead, criteria will be set using properties important for establishing which nano-scale chemicals require pre-introduction assessment.  The categorisation outcomes for unlisted chemicals consisting of particles at the nanoscale that meet the specific nano-scale criteria (discussed below) will be:

• Exempted if introduced at ≤10 kg/annum for the purposes of research and development, or as a contained import/export introduction
• Reported if introduced at >10 kg/annum and ≤100 kg/annum for the purposes of research and development
• Assessed in all other circumstances.

The information we will need as part of the application for an Assessed introduction will be commensurate with the Exposure Band (similar to other types of industrial chemicals). We will consult further on these requirements later in the year.

For the introduction of chemicals consisting of particles at the nanoscale that do not meet the criteria discussed below, the categorisation will be the same as other unlisted industrial chemicals and may result in it being categorised as Assessed, Reported or Exempted. It will therefore depend on the exposure (volume and use) and the hazard characteristics of the chemical (with information requirements for hazard depending on the Exposure Band).

Categorisation criteria

We propose that criteria be prescribed to determine if the introduction of an unlisted chemical consisting of particles at the nanoscale will be categorised as Assessed, Reported or Exempted. This would be instead of having a static definition of a ‘nanomaterial’. This allows flexibility as criteria for industry self-categorisation could be different to the criteria we would use to appropriately focus an AICIS initiated evaluation of listed chemicals.

The categorisation criteria may incorporate some or all of the below elements:

• size and distribution
• intentionally manufactured
• size-dependent properties
• aggregates and agglomerates
• solubility/dissolution rate.

Many of these elements are in our current working definition of nanomaterial and international definitions. We have reviewed each of these elements to consider their appropriateness in setting criteria to determine the categorisation outcomes for unlisted chemicals under the new framework.

Several options exist for which elements to include and how to incorporate each of the elements in the categorisation criteria. We have considered the impact of these elements (and how clearly they are expressed) on the ability to aid and enforce compliance under the new scheme, with its shift to more industry self-categorisation.

We discuss the relevant considerations for each of these elements below, as well as the possible categorisation criteria structure.

Size and distribution

The current working definition includes a nanoscale range, defined as:

• ‘typically between 1 and 100 nm’, and
• there is an interpretative note that ‘where a material includes 10% or more number of particles that meet the above definition (size, unique properties, intentionally produced) we will consider this to be a nanomaterial’.

The term ‘typically’ is ambiguous. It may cause issues for compliance and enforcement when applied in the context of industry self-categorisation. For this reason, an objective size range of 1-100 nm (as used in some overseas definitions or criteria) will be used. This has the advantage of being enforceable criteria if a compliance issue arises.

The use of a size distribution threshold is desirable but should be included with the size aspect so that these two closely related concepts are considered together.

We could maintain the current ‘10% by number’ threshold in the working definition, or alternatives could be considered, such as aligning with those implemented overseas:

• 50% or more of the particles in the number size distribution (EU)
• 10% by weight (US).

These distribution threshold options would need to be considered in conjunction with other criteria such as the size-dependent properties that may need to be included.

Both approaches have limitations. A size distribution based on particle number can bias the distribution to the smallest particles and so categorise a chemical at the nanoscale when the majority of particles are not in the nanoscale. Whereas a weight (or mass) based distribution has the potential to underestimate the true size distribution as the number of particles in any given mass of substance increases disproportionately as the size of the particle decreases.

Current state technology for measuring distribution thresholds for particles in the nanoscale also needs to be taken into account. For example, measuring particle numbers in the nanoscale with precision can be challenging, particularly when the threshold is low.

Intentionally manufactured

The current working definition includes ‘intentionally produced, manufactured or engineered’ as well as an interpretative note that ‘intentionally produced, manufactured or engineered materials are distinct from accidentally produced materials’.

When considering this criterion in the context of unlisted chemicals, it is worth noting that under the reformed scheme, the following will be considered as excluded introductions (not needing categorisation):

• naturally occurring nanoforms of chemicals
• incidentally introduced chemicals.

The exclusion of these chemicals will thus not need to be taken into account when deciding what chemicals should be excluded through the nanoscale criteria.

Chemicals that are ‘incidentally introduced’ include those introduced because of:

• impurities in other introduced chemicals
• the occurrence of a chemical reaction during the manufacture or use of another chemical.

This applies only where the introduction of the incidentally introduced chemical has no commercial value, separate from the other chemical.

This exclusion of incidentally introduced chemicals would not cover the situation where only a proportion of the unlisted chemical is introduced at the nanoscale, but the introducer was not intending introduction at the nanoscale. Some of these situations may be covered if a size distribution threshold (such as 10% by number discussed above) was incorporated into the categorisation criteria for nanoscale chemicals.

The inclusion of an ‘intentionally introduced’ criterion may be challenging. It may create issues for compliance and enforcement, when trying to determine:

• the introducer’s intent and
• if the introducer has miscategorised their chemical introduction by declaring they did not intend for the nanoscale form to be present in the introduced chemical.

For introduction at the nanoscale it may be easier in some cases to determine the introducer’s intent if they are seeking specific properties that only occur at the nanoscale.

There is also the question if the potential risk to human health and the environment is any different when the nanoscale form is intended for introduction, as opposed to when it is unintentional.

The option for this criterion would be:

1. not include the requirement for ‘intentionally produced, manufactured or engineered’
2. include this requirement as a criterion that a chemical at the nanoscale (and with all other criteria fulfilled) would only be categorised as Assessed if the introducer intended its introduction at the nanoscale.
3. include it as an exclusion criterion that a chemical at the nanoscale (and with all other criteria fulfilled) would be categorised as Assessed, unless the introducer could show that the introduction of the nanoscale form of the chemical is incidental to the introduction of the non-nanoscale form.

Size-dependent properties

The current working definition includes:

• ‘unique properties or specific composition at the nanoscale’
• there is an interpretive note that ’unique properties' refers to chemical and/or physical properties that are different because of a material’s nanoscale features when compared with the same material without nanoscale features, and result in ‘unique phenomena’
• e.g. increased strength, chemical reactivity or conductivity that enables novel applications.

This criterion’s purpose would be to help focus regulatory activities on chemicals that have the potential for increased risk compared to their non-nano forms.

Including this criterion may cause difficulty for industry self-categorisation of unlisted chemicals as:

• it is descriptive in nature
• its interpretation may be subjective.

It would also be difficult to define and measure. This would increase the complexity in applying it. Also, this criterion assumes that there is a non-nanoscale form available for comparison. This may not be true for some unlisted chemicals.

This criterion may increase the likelihood of miscategorisation by an introducer. It may be difficult for us to determine compliance with the categorisation criteria.

It could be an exclusion criterion such that a chemical at the nanoscale (and with all other criteria fulfilled) would be categorised as Assessed, unless the introducer could show that the nanoscale form of the chemicals had the same reactivity and toxicity as the non-nanoscale form.

Some overseas regulatory definitions (e.g. EU and Canada) do not include size-dependent properties for chemicals introduced at the nanoscale of 1-100 nm. Others have included it in criteria where it has been appropriate for the context (e.g. US in the criteria for their “Nanoscale – Reporting Rule”).

Aggregates and agglomerates

The current working definition includes materials that are ‘nanostructured (i.e. having an internal or surface structure at the nanoscale)’. The interpretative note says that ‘aggregates and agglomerates are considered to be nanostructured substances’.

Many other definitions/criteria are explicit in their consideration of aggregates and agglomerates, and do not include the term ‘nanostructured’.

An option to consider for the categorisation criteria is to replace ‘nanostructured substances’ with an explicit description of the inclusion of aggregates and agglomerates.

This would ensure the treatment of aggregates and agglomerates of nanoparticles is clear. Also, this would mean the criterion would not capture other type of materials such as nanoporous materials.

The options for this criterion would be:

1. Keep the term ‘nanostructured’ and be explicit in the criterion (rather than a note) that this includes aggregates and agglomerates; or
2. Remove the term ‘nanostructured’ and refer to particles (when describing the size range and distribution threshold) as being in the ‘unbound state or as a constituent of aggregates or agglomerates’.

Solubility/dissolution rate and persistence at the nanoscale

The current working definition does not include the solubility/dissolution rate element, and it is not included in many other overseas definitions. It is included as a criterion in deciding which nanomaterials may need extra information to be submitted under the current notification and assessment framework.

It has been identified as a key parameter by the OECD Working Party on Manufactured Nanomaterials (WPMN).

If this were to be included as a criterion, the dissolution rate that triggered categorisation would need to be objectively defined in accordance with international guidelines. This is an active area of development under the OECD WPMN guidelines program.

In addition, we could take into account whether the chemical introduced at the nanoscale persisted at the nanoscale during its use. For example, polymer micelles at the nanoscale often do not persist outside of the environment in which they are contained.

Possible structure for categorisation criteria

We provide an example below of how some of the elements could be combined into categorisation criteria for unlisted chemicals. As this possible structure is just for example purposes, it makes a number of assumptions about which option is used for each of the elements.

Introduction of an unlisted chemical consisting of particles at the nanoscale will be categorised as Assessed if:

1. The introduced chemical consists of particles, in an unbound state or as an aggregate or as an agglomerate, 10% of which (by number size distribution) have at least one external dimension in the nanoscale range of 1-100 nm, AND
2. The chemical is introduced as a solid or in a dispersion.

unless the:

• introduction is for the purposes of research and development and the introduction volume is less than 100 kg (Categorisation outcome = Reported or Exempted) OR
• introduction is contained import/export (Categorisation outcome = Exempted) OR
• introduced chemical rapidly dissolves in water (categorise in the same way as other unlisted chemicals) OR
• introduced chemical does not persist at the nanoscale during its intended use (categorise in the same way as other unlisted chemicals) OR
• the introduction of the nanoscale form of the chemical is incidental to the introduction of the non-nanoscale form (categorise in the same way as other unlisted chemicals).

Note that this example incorporates the following elements:

• size and distribution
• aggregates and agglomerates
• solubility/dissolution rate and persistence at the nanoscale.

The example does not incorporate the following elements:

• size-dependent properties.

Next - Section 7.2: Background

Go back to the start of Part 7 Regulatory treatment of unlisted chemicals introduced at the nanoscale

In previous consultation papers, we proposed that nanomaterials would be characterised in the highest hazard bands for human health and the environment (due to the uncertainty about their risks and the complexity of the required risk assessment). Thus, they would be categorised as Assessed, except when introduced in scenarios fitting into Exposure Band 1 (i.e. Research and development ≤ 100 kg/annum, or contained import/export).

Stakeholders expressed concern about the way nanomaterials were being represented in the matrix, as well as views that the research and development volume threshold for Exposure Band 1 (≤ 100 kg/annum) was too high for nanomaterials.

Previous consultation papers also proposed that nanomaterials be defined in the new legislation using our current working definition for industrial nanomaterials, which is:

• industrial materials intentionally produced, manufactured or engineered to have unique properties or specific composition at the nanoscale, that is a size range typically between 1 nm and 100 nm, and is either a nano-object (i.e. confined in one, two, or three dimensions at the nanoscale) or is nanostructured (i.e. having an internal or surface structure at the nanoscale)

Notes to the working definition:

• intentionally produced, manufactured or engineered materials are distinct from accidentally produced materials
• 'unique properties' refers to chemical and/or physical properties that are different because of a material's nanoscale features when compared with the same material without nanoscale features, and result in unique phenomena (e.g. increased strength, chemical reactivity or conductivity) enabling novel applications
• aggregates and agglomerates are considered to be nanostructured substances
• where a material includes 10% or more number of particles that meet the above definition (size, unique properties, intentionally produced) we will consider this to be a nanomaterial.

Stakeholder feedback on the proposal to use the working definition included concerns that the definition was too conservative in its use of a 10% by number particle threshold, with calls to align with other international definitions (US or EU).

We have used the working definition to:

• facilitate voluntary calls for information
• identify new chemicals unsuitable for current exemption categories
• identify the notified chemicals that require additional data when assessed under the current ICNA Act.

The use of this definition for determining chemicals unsuitable for current exemption categories has involved self-assessment against the working definition by industry, but this has been limited to the low volumes allowable under the exemption categories (e.g. <100 kg/year).

The proposed categorisation framework for the reformed scheme is, however, significantly different to the current new chemicals notification framework, due to a greater reliance on self-categorisation by industry (including of higher volume introductions), in which the outcomes are:

• Exempted (no reporting to us)
• Reported (pre-introduction report to us)
• Assessed (pre-introduction assessment by us).

The context in which a definition or set of criteria are being used to determine what is considered a ‘nanomaterial’ needing pre-introduction assessment is therefore different between the current and reformed schemes. Although the working definition has been very useful in administering the ICNA Act, it may not be directly applicable to the new risk-proportionate regulatory scheme the Australian Government has agreed. This new scheme has a very different balance of pre-and post-introduction assessment, with industry self-categorisation.

Since we developed our current working definition, considerable work on nanomaterials by bodies such as the OECD has taken place. Many other regulatory agencies have also now developed definitions and/or criteria to support their own work in this area. It is an opportune time to review our working definition and to decide how to use it (or elements of it) in the reformed industrial chemicals scheme.

Next - Part 8: Commercial evaluation authorisation