The NPI gives information on the types and amounts of 93 toxic substances being emitted into the Australian environment.
A panel of technical experts was formed in March 1997 to recommend substances for inclusion on the NPI. The Technical Advisory Panel (TAP) used a risk-based approach for recommending which substances should be on the reporting list.
The TAP first developed criteria for selecting substances to the reporting list. These criteria were:
- environmental effects
- human health effects, and
The TAP considered 420 substances against these criteria. The list included some agricultural and veterinary substances but excluded substances that were:
- banned in Australia or scheduled for phase-out
- ozone depleters, and
- greenhouse gases.
All substances on the master list were scored against each of the above criteria. The hazard scores varied between 0 and 3 for both environmental effect and human health. For example, the health hazard score for lead and compounds was 1.75, and the environment hazard score for lead and compounds was 2.5.
These hazard scores were used to generate a number which approximated the relative risk that each substance poses in Australia. This risk is expressed as:
- Risk score = (environment hazard score + human health hazard score) x exposure
The risk scores generated by this process occur between 0 and 18. They were used to rank the substances. The TAP recommended that substances with a risk score of 3 or higher should be included on the NPI. There were 90 substances which scored 3 or higher in this process and all of these substances are on the reporting list. This approach means that substances with a high hazard score but low likelihood of exposure to Australia's population or environment may have a lower risk rating (hence lower NPI rank) than substances with a lower hazard score but higher chance of exposure.
There are fact sheets on the NPI website for the substances on the NPI reporting list. The fact sheets have information about how you might be exposed to the substance, how exposure might affect you and the environment, common uses, comparative data and physical and chemical properties.