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Ethene, chloro-: Human health tier II assessment

11 April 2014

CAS Number: 75-01-4

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Preface

This assessment was carried out by staff of the National Industrial Chemicals Notification and Assessment Scheme (NICNAS) using the Inventory Multi-tiered Assessment and Prioritisation (IMAP) framework.

The IMAP framework addresses the human health and environmental impacts of previously unassessed industrial chemicals listed on the Australian Inventory of Chemical Substances (the Inventory).

The framework was developed with significant input from stakeholders and provides a more rapid, flexible and transparent approach for the assessment of chemicals listed on the Inventory.

Stage One of the implementation of this framework, which lasted four years from 1 July 2012, examined 3000 chemicals meeting characteristics identified by stakeholders as needing priority assessment. This included chemicals for which NICNAS already held exposure information, chemicals identified as a concern or for which regulatory action had been taken overseas, and chemicals detected in international studies analysing chemicals present in babies’ umbilical cord blood.

Stage Two of IMAP began in July 2016. We are continuing to assess chemicals on the Inventory, including chemicals identified as a concern for which action has been taken overseas and chemicals that can be rapidly identified and assessed by using Stage One information. We are also continuing to publish information for chemicals on the Inventory that pose a low risk to human health or the environment or both. This work provides efficiencies and enables us to identify higher risk chemicals requiring assessment.

The IMAP framework is a science and risk-based model designed to align the assessment effort with the human health and environmental impacts of chemicals. It has three tiers of assessment, with the assessment effort increasing with each tier. The Tier I assessment is a high throughput approach using tabulated electronic data. The Tier II assessment is an evaluation of risk on a substance-by-substance or chemical category-by-category basis. Tier III assessments are conducted to address specific concerns that could not be resolved during the Tier II assessment.

These assessments are carried out by staff employed by the Australian Government Department of Health and the Australian Government Department of the Environment and Energy. The human health and environment risk assessments are conducted and published separately, using information available at the time, and may be undertaken at different tiers.

This chemical or group of chemicals are being assessed at Tier II because the Tier I assessment indicated that it needed further investigation.

For more detail on this program please visit:www.nicnas.gov.au

Disclaimer

NICNAS has made every effort to assure the quality of information available in this report. However, before relying on it for a specific purpose, users should obtain advice relevant to their particular circumstances. This report has been prepared by NICNAS using a range of sources, including information from databases maintained by third parties, which include data supplied by industry. NICNAS has not verified and cannot guarantee the correctness of all information obtained from those databases. Reproduction or further distribution of this information may be subject to copyright protection. Use of this information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner. NICNAS does not take any responsibility whatsoever for any copyright or other infringements that may be caused by using this information.

Acronyms & Abbreviations

Chemical Identity

Synonyms Chloroethene
Chloroethylene
Vinyl chloride
Vinyl chloride, monomer
Monochloroethylene
Structural Formula Structural formula of Ethene, chloro-
Molecular Formula C2H3Cl
Molecular Weight (g/mol) 62.499
Appearance and Odour (where available) Colourless gas with a sweet odour.
SMILES C(=C)Cl

Australian

According to the National Pollutant Inventory, this chemical is used for the production of polyvinyl chloride (PVC), which in turn is used for various plastic products. It was also reported that this chemical was previously used as a refrigerant.

International

The following international manufacture and uses have been identified through the International Programme on Chemical Safety Environmental Health Criteria (IPCS EHC); International Program on Chemical Safety Health and Safety Guide (HSG); US Agency for Toxic Substances and Disease Registry (ATSDR) report; International Agency for Research on Cancer (IARC) monograph; and the Organisation for Economic Cooperation and Development Screening Information Dataset Initial Assessment Report (OECD SIAR).

This chemical is a highly reactive, gaseous substance that is manufactured in closed systems. It does not occur naturally. However, breakdown of other substances such as trichloroethane by certain microorganisms may result in the natural formation of this chemical. It is produced industrially either through the hydrochlorination of acetylene or through the thermal cracking of 1,2-dichloroethane.

The chemical has reported site-limited use in:

  • the production of polyvinyl chloride (PVC) and vinyl copolymers.

Australian

The chemical is listed in the following:

  • under Appendix A 'goods too dangerous to be transported' in the Australian Code for the Transport of Dangerous Goods by Road and Rail (NTC, 2007). This restriction does not apply to stabilised vinyl chloride.
  • Australia New Zealand Food Standards Code Standard 1.4.1—Contaminants and Natural Toxicants—Maximum levels of non-metal contaminants in food, the chemical is restricted to a maximum concentration of 0.01 mg/kg in all food types.  
  • Australian Drinking Water Guidelines 2011 state: 'No safe concentration for vinyl chloride in drinking water can be confidently set. However, for practical purposes, the concentration should be less than 0.0003 mg/L, which is the limit of determination' (NHMRC, 2011).
  • Work Health and Safety Regulations 2011, the chemical is listed in table 10.2 under schedule 10 as a restricted carcinogen, which cannot be used at a concentration greater than 0.1 % without authorisation from the appropriate state or territory regulator (WHS, 2011).  
  • The Poisons Standard (Standard for the Uniform Scheduling of Medicines and Poisons (SUSMP)) in Schedule 7 (Dangerous poison—Substances with a high potential for causing harm at low exposure and which require special precautions during manufacture, handling or use).  The chemical is listed with condition 1 'Not to be available except to authorised or licensed persons' under appendix J of the SUSMP.  

International

The chemical is listed in the following:

  • International Air Transport Association (IATA) Dangerous Goods Regulations—Prohibited List Passenger and Cargo Aircraft: the chemical cannot be transported on passenger or cargo aircraft in any quantity.
  • Canada, Health Canada, Consumer Product Safety Bureau, Cosmetics Division, Canada List of prohibited and restricted cosmetic ingredients (The Cosmetic Ingredient "Hotlist"), March 2011
  • EU Cosmetic Directive 76/768/EEC Annex II: List of substances which must not form part of the composition of cosmetic products.
  • New Zealand Cosmetic Products Group Standard—Schedule 4: Components cosmetic products must not contain.
  • US EPA—Banned or severely restricted pesticides.
  • US, Clean Air Act, Section 112(b)(1) Hazardous air pollutants initial list (1990) and amendments (including 70 FR 75047, December 19, 05)
  • WHO (World Health Organization) Guidelines for Drinking-water Quality, Fourth Edition, 2011.  The guideline for the chemical is 0.0003 mg/L.  
  • Canada Environmental Protection Act (CEPA) 1999—Schedule 1 Toxic Substances List.
  • US—California Proposition 65—No significant risk levels (NSRLs) adopted in regulation for carcinogens. The NSRL for the chemical is 3 µg/d.

Existing Work Health and Safety Controls

Hazard Classification

The chemical is currently classified on the Hazardous Substances Information System (HSIS) (may be accessed at http://hsis.safeworkaustralia.gov.au/HazardousSubstance) with the following risk phrases:

F+; R12

Carc. Cat. 1; R45

Australian

TWA: 13 mg/m³ (5 ppm)

International

The following exposure standards are identified (Galleria Chemica):

An exposure limit (TWA) of 2.6–7.8 mg/m³ (1–2 ppm) in different countries such as the USA, South Korea, Canada (Quebec), France and Germany. Japan and the United Kingdom have exposure limits (TWA) of 6.5 mg/m3 (2.5 ppm) and 7.8 mg/m³ (3 ppm) respectively.

Toxicokinetics

The chemical is readily absorbed in humans and animals following oral or inhalation exposure, but dermal absorption is very low (OECD, 2001).

Oral

The chemical is of low acute toxicity through ingestion in rats, with an LD50 of  >4000 mg/kg (OECD, 2001).    

Dermal

No data are available. The chemical is assumed to be of low acute dermal toxicity due to low acute systemic toxicity and very low dermal absorption.

Inhalation

The chemical is of low acute toxicity when inhaled, with LC50s of 390 mg/L, 294 mg/L, 595 mg/L and 595 mg/L in rats, mice, rabbits and guinea pigs respectively.  The chemical causes intense salivation and lacrimation in rats, guinea pigs and rabbits exposed to high concentrations (375–700 mg/L) (OECD, 2001).

Observation in humans

The chemical, at a concentration of 8000 ppm, produced no signs of toxicity after 5 minutes of exposure in humans. However at concentrations of 12000 to 20000 ppm, dizziness, headache and nausea were noted (OECD, 2001).

Skin Irritation

When placed on the skin or in the eyes in liquid form, the chemical may freeze tissues as it evaporates (OECD, 2001).  

Eye Irritation

The chemical causes intense lacrimation in rats, guinea pigs and rabbits exposed to high concentrations (375–700 mg/l).  When placed on the skin or in the eyes in liquid form, the chemical may freeze tissues as it evaporates (OECD, 2001).  

Skin Sensitisation

There was no information available on the sensitisation potential of the chemical.

Oral

Classification is warranted due to high repeat-dose toxicity by ingestion or inhalation, with the liver being the main target organ.

Oral administration of 30 mg/kg/day for 13 weeks, or 0.13 mg/kg/day for 149 weeks, produced no adverse effects in rats. Lifetime oral exposure to doses ³1.3 mg/kg/day is toxic to the liver of rats, with the NOEL being 0.13 mg/kg/day (OECD, 2001).

Inhalation

The inhalation no observed adverse effect concentration (NOAEC) in rats, rabbits, guinea pigs or dogs is 50 ppm for six months. Exposure of rats to 50 ppm for longer periods (10–12 months) is associated with decreased body weight, slightly increased mortality, and increased weights of some organs. Mice exposed to concentrations =50 ppm for 12 months exhibit changes in the liver and other organs (OECD, 2001).

Observation in humans

Repeated exposure to the chemical has been associated with vinyl chloride disease and cancer (OECD, 2001).  

Genotoxicity

The chemical is not currently classified for genotoxicity. However, the data available support the need for classification (refer to Recommendations section) based on the findings reported below.

There are are numerous in vitro (both with and without metabolic activation) and in vivo genotoxicity studies on the chemical showing DNA damage (OECD, 2001).  The chemical has also been observed to cause an excess of chromosomal aberrations in the peripheral blood lymphocytes of exposed workers (HSDB, 2012).  There are no in vitro studies conducted using germ cells.

Carcinogenicity

The chemical is classified as a Category 1 Carcinogen with the risk phrase 'May cause cancer (R45)' in Australia. The data available support this classification.  

In lifetime (135–149 weeks) oral toxicity studies in rats, the chemical's carcinogenic effects included hepatocellular carcinoma; hepatic, pulmonary, abdominal angiosarcoma; Zymbal gland tumours with a lowest observed effect level (LOEL) of 1.3 mg/kg bw/d and a no observed adverse effect level (NOEL) of 0.13 mg/kg bw/d (OECD, 2001). The chemical has also been associated with the formation of liver tumours in humans (IARC, 2008; OECD, 2001).

The IARC has classified the chemical as 'carcinogenic to humans (Group 1)', based on sufficient evidence in both humans and animals that it causes cancer.  

The chemical does not show specific reproductive or developmental toxicity, with any effects seen in animal studies only at or above levels that also produce maternal toxicity. In a combined reproductive-developmental study on rats, a NOAEC of ³1100 ppm was obtained (OECD, 2001).

Studies of communities living near PVC production facilities showed no statistically significant correlation between proximity to the facilities or parental occupation and any adverse developmental effects (OECD, 2001).  

Critical Health Effects

The critical effect for risk characterisation is carcinogenicity.

Public Risk Characterisation

No public health risks are foreseen as the chemical is only expected to be used as a reactant in PVC production.

Occupational Risk Characterisation

Given the critical health effect, controls for handling and using the chemical to ensure low worker exposure indicate that its use is unlikely to elicit local or acute toxicity effects.

During product formulation, ocular and inhalation exposure of workers to the chemical could occur. The level and route of exposure will vary depending on the method of application and work practices employed.

Given the critical, systemic, long-term health effect, the chemical may pose an unreasonable risk to workers unless adequate control measures to minimise inhalation exposure to the chemical are implemented. The chemical should be appropriately classified and labelled to ensure that a person conducting a business or undertaking (PCBU) has adequate information to determine appropriate controls.

The control measures put in place to minimise the carcinogenic risk should adequately control risks associated with all of the health hazards documented above.

The data available support an amendment to the hazard classification in HSIS (refer to the Recommendation section).

In Australia, the chemical is a restricted carcinogen under Work Health and Safety (WHS) Regulations (2011). A person conducting a business or undertaking must apply in writing to the regulator for authorisation to use, handle or store a restricted carcinogen at the workplace.

It is also listed on Schedule 7 of the SUSMP (requiring a label heading, 'Dangerous Poison'). Schedule 7 substances should be available only to specialised or authorised users who have the skills necessary for safe handling. Special regulations restricting the chemical's availability, possession, storage or use may apply.

The current Australian exposure standard of 13 mg/m³ (5 ppm) TWA may require reconsideration. International exposure standards are in the range of 2.6 mg/m³ (1 ppm) to 7.8 mg/m³ (3 ppm), which is significantly less than the current Australian level.  

Information has been provided by the only Australian company using the chemical to indicate that exposures in their plant are controlled to levels well below the current exposure standard.

NICNAS Recommendation

This chemical is a restricted carcinogen in Australia under the WHS Regulations 2011. There are specific obligations for suppliers of this chemical, and obligations for persons conducting a business or undertaking (PCBU), to protect the safety of workers using/handling/storing the chemical (Work Health and Safety Regulations 2011).  

Information about the status of the chemical as a restricted carcinogen under the WHS Regulations (2011) should be included in the Australian Inventory of Chemical Substances (AICS) according to section 13(1)(b) of the Industrial Chemicals (Notification and Assessment) Act 1989.

The chemical is classified as a Category 1 carcinogen (HSIS) and has an exposure standard for workplace use/exposure. However, not all of the potential health effects of the chemical are covered by the current classification and it should be expanded as detailed in the occupational health and safety section below.  

Although the chemical has a current exposure standard of TWA 13 mg/m³ (5 ppm), this is higher than that specified in other juristrictions. Considering that adverse effects were seen in 12-month repeated inhalation toxicity studies at 50 ppm with no NOEC able to be set in these studies, the current exposure standard may not provide sufficient protection for workers with long-term repeated exposure to the chemical.

A Tier III assessment may be necessary to provide further information as to whether the current exposure controls and other standards are appropriate to offer adequate protection to workers and the public.

Public Health

As previously stated, the chemical is listed in Schedule 7 of the SUSMP and should be available only to specialised or authorised users who have the skills necessary to handle them safely. Special regulations restricting their availability, possession, storage or use may apply with appropriate warning statements and safety directions.

The chemical is not expected to be present in consumer products as it is only permitted to be used as a reactant to manufacture other chemicals.

These existing regulatory controls are considered adequate.

Work Health and Safety

The chemical is recommended for classification labelling under the current approved criteria and adopted GHS as below:

Hazard Approved Criteria (HSIS)a GHS Classification (HCIS)b
Repeat Dose Toxicity Danger of serious damage to health by prolonged exposure (T; R48) Causes damage to organs through prolonged or repeated exposure - Cat. 1 (H372)
Genotoxicity Muta. Cat 3 - Possible risk of irreversible effects (Xn; R68) Suspected of causing genetic defects - Cat. 2 (H341)
Carcinogenicity Carc. Cat 1 - May cause cancer (T; R45)* May cause cancer - Cat. 1A (H350)

a Approved Criteria for Classifying Hazardous Substances [NOHSC:1008(2004)].

b Globally Harmonized System of Classification and Labelling of Chemicals (GHS) United Nations, 2009. Third Edition.

* Existing Hazard Classification. No change recommended to this classification

Advice for industry

Control measures

Control measures to minimise the risk from ocular/inhalation exposure to the chemical should be implemented in accordance with the hierarchy of controls. Approaches to minimise risk include substitution, isolation and engineering controls. Measures required to eliminate or minimise risk arising from storing, handling and using a hazardous chemical depend on the physical form and the manner in which the chemical is used. Examples of control measures which may minimise the risk include, but are not limited to:

  •  using closed systems or isolating operations;
  •  using local exhaust ventilation to prevent the chemical from entering the breathing

    zone of any worker;

  •  health monitoring for any worker who is at risk of exposure to the chemical if valid

    techniques are available to monitor the effect on the worker’s health;

  •  air monitoring to ensure control measures in place are working effectively and

    continue to do so;

  •  minimising manual processes and work tasks through automating processes;
  •  work procedures that minimise splashes and spills;   
  •  regularly cleaning equipment and work areas; and
  •  using protective equipment that is designed, constructed, and operated to ensure

    that the worker does not come into contact with the chemical.

Guidance on managing risks from hazardous chemicals are provided in the Managing Risks of Hazardous Chemicals in the Workplace—Code of Practice  available on the Safe Work Australia website.

Personal protective equipment should not solely be relied upon to control risk and should only be used when all other reasonably practicable control measures do not eliminate or sufficiently minimise risk. Guidance in selecting personal protective equipment can be obtained from Australian, Australian/New Zealand or other approved standards.

Obligations under workplace health and safety legislation

Information in this report should be taken into account to assist with meeting obligations under workplace health and safety legislation as adopted by the relevant state or territory.  This includes, but is not limited to:

  •  ensuring that hazardous chemicals are correctly classified and labelled;
  •  ensuring that (material) safety data sheets ((m)SDS) containing accurate

    information about the hazards (relating to both health hazards and

    physicochemical (physical) hazards) of the chemical are prepared; and

  •  managing risks arising from storing, handling and using a hazardous chemical.

Your work health and safety regulator should be contacted for information on the work health and safety laws in your jurisdiction.

Information on how to prepare an (m)SDS and how to label containers of hazardous chemicals are provided in relevant codes of practice such as the Preparation of Safety Data Sheets for Hazardous Chemicals— Code of Practice and Labelling of Workplace Hazardous Chemicals—Code of Practice, respectively. These codes of practice are available from the Safe Work Australia website.

A review of the physical hazards of the chemical has not been undertaken as part of this assessment.

References

Agency for Toxic Substances and Disease Registry (ATSDR) 2006. Vinyl Chloride (CAS 75-01-4). Accessed October 2012 at http://www.atsdr.cdc.gov/PHS/PHS.asp?id=280&tid=51.

Australia New Zealand Food Standards Code - Standard 1.4.1 - Contaminants and Natural Toxicants. Accessed October 2012 at http://www.comlaw.gov.au/Details/F2011C00542.

Hazardous Substances Data Bank (HSDB). National Library of Medicine. Accessed October 2012 at http://toxnet.nlm.nih.gov.

International Agency for Research on Cancer (IARC) 2008. 1,3-Butadiene, Ethylene Oxide and Vinyl Halides (Vinyl Fluoride, Vinyl Chloride and Vinyl Bromide), IARC Monographs Volume 97. Accessed October 2012 at http://monographs.iarc.fr/ENG/Monographs/vol97/index.php.

International Programme on chemical Safety (IPCS) 1999. Vinyl Chloride. Environmental Health Criteria 215. World Health Organisation, Geneva. Accessed October 2012 at http://www.inchem.org/documents/ehc/ehc/ehc215.htm#SectionNumber:3.3.

National Health and Medical Research Council. National Water Quality Management Strategy, Australian Drinking Water Guidelines. Accessed October 2012 at http://www.nhmrc.gov.au/guidelines/publications/eh52.

National Pollutant Inventory (NPI). Accessed October 2012 at http://www.npi.gov.au/index.html.

National Transport Commission (NTC) 2007 Australian Code for the Transport of Dangerous Goods by Road and Rail (ADG code), 7th Edition, Commonwealth of Australia.

OECD 2001. SIAR on Vinyl Chloride (75-01-4). Accessed October 2012 at http://webnet.oecd.org/HPV/UI/Search.aspx

The International Programme on Chemical Safety (IPCS) 1999, Vinyl Chloride Health and Safety Guide. Health and Safety Guide No. 109. Accessed October 2012 at http://www.inchem.org/documents/hsg/hsg/hsg109.htm#SectionNumber:1.5.

Work Health and Safety (WHS) Regulations 2011. Schedule 10 - Prohibited carcinogens, restricted carcinogens and restricted hazardous chemicals. Accessed October 2012 at http://www.comlaw.gov.au/Details/F2011L02664

Last update 11 April 2014