How chemicals are assessed
Last update 17 August 2017
The Inventory Multi-tiered Assessment and Prioritisation (IMAP) framework is a science and risk based framework for the assessment and prioritisation of chemicals on the Australian Inventory of Chemical Substances (AICS). It consists of 3 tiers of assessment, with the assessment effort increasing with each tier. The aim is to provide more timely information about the hazards and risks associated with the use of industrial chemicals by identifying chemicals which:
- pose no unreasonable risk to human health or the environment (Tier I human health assessment, Tier I environment assessment)
- require risk management measures to be instituted for safe use (Tier II human health assessment, Tier II environment assessment)
- require more in-depth assessment to fully determine its impact on human health and/or the environment (Tier III human health assessment, Tier III environment assessment).
Tools, criteria and international assessment approaches were considered during development of the IMAP framework with a focus on Canada, USA, Europe and international agencies such as the Organisation for Economic Co-operation and Development (OECD) and the World Health Organisation (WHO).
The framework aims to resolve the main issues raised by stakeholders which include information on exposure, reducing duplication by using information generated overseas and achieving assessment outcomes early in the program.
IMAP framework key features
Scientifically robust risk based approach
The framework uses simple and transparent criteria to determine the potential exposure and risks from chemicals to human health and the environment. The framework also allows for expert judgement, such as peer review to be applied where appropriate.
Achieving assessment outcomes early in the framework
This approach takes into account advice and requests from stakeholders, including industry and the community, to produce assessment outcomes early in the program and for each tier (see Figure 1). The effort and resources being used should match the potential risk of the chemical.
At each successive tier, the comprehensiveness (and hence resource intensiveness) of the assessments increases, while the number of chemicals requiring assessment decreases.
Using overseas data
A number of other countries and international agencies are generating or gathering information about the human health and environmental effects of a broad range of chemicals. To ensure efficiency and reduce duplication of effort, NICNAS is using this information (where appropriate) in the Australian
To maximise this information, the framework's human health and environmental scientific criteria are aligned with existing hazard classification frameworks already in use across industry and internationally.
Advancements in assessment methodologies
To ensure best practice in assessing chemicals in Australia, internationally recognised assessment tools are used to fill gaps in data on a number of human health and environmental hazard indicators.
Tools and approaches being used are Quantitative Structure Activity Relationship (QSAR) models or computational models for predicting toxicity and data from suitable analogue (similar) chemicals.
A flexible approach to exposure information (actual, surrogate or default)
The greatest challenge when assessing the risks of chemicals on AICS is limited information on identity, volume and usage on chemicals currently being imported and/or manufactured in Australia.
The framework uses surrogate information to estimate exposure, such as from overseas sources, or conservative default values (where actual or surrogate information is not available) in the early stages (Tier I and Tier II assessments).
Targeted Tier I approaches
Low concern polymers
Our approaches in identifying low concern polymers under the IMAP framework. Identifying these chemicals allows us to prioritise assessment of higher risk chemicals.
Identification of chemicals of low concern to human health
The approach used by NICNAS to identify chemicals of low concern to human health was primarily based on the approach used by Health Canada.
Excluded (non-industrial) use chemicals on AICS
NICNAS is screening the AICS for excluded use chemicals which are not considered to be relevant industrial chemicals and do not need Tier II assessments.