The substances reportable to the NPI are listed in Table 1 of Schedule A to the NPI NEPM. Each entry has a name, a Chemical Abstracts Service (CAS) number where one applies, and a threshold category that decides when it must be reported.
Key points
- 93 substances listed in Schedule A, Table 1 of the NPI NEPM
- Each substance has a threshold category
- The list grew from 36 to 90 to 93 substances by 2007-08
- Facilities must report every substance they trip
- Greenhouse gases are not NPI substances
How the list was chosen
Substances were selected for their potential effect on human health and the environment. The list has grown over time, from 36 substances in the first three reporting years (1998 to 2001), to 90 from 2001-02, and to the current 93 from 2007-08.
What the list includes
The list spans metals and metal compounds, acids, combustion by-products such as oxides of nitrogen, carbon monoxide and sulfur dioxide, particulate matter as PM10 and PM2.5, polycyclic aromatic hydrocarbons, dioxins and furans, individual organic chemicals such as benzene, total volatile organic compounds (TVOC), and the nutrients total nitrogen and total phosphorus.
How the list is applied
A facility reports only the substances whose threshold it exceeds, but it must report every substance it trips. Special counting rules apply to some entries. For a “metal and compounds” entry, the threshold counts the total amount of the metal and its compounds used, but emissions and transfers are reported as the mass of the metal only. PM2.5 is reportable only from burning fuel or waste.
What is not included
Greenhouse gases such as carbon dioxide and methane are not NPI substances. They are covered by the National Greenhouse Accounts and the NGER scheme.
Where to find the full list
DCCEEW publishes the full substance list with each substance’s threshold category. The NPI Guide lists all 93 substances in Appendix A, with notes on how each is counted.
Why it matters
Many facilities trip thresholds for substances they never buy, because the substances are produced by combustion or are present in ore, fuel or raw materials. Checking the full list against site inputs and processes each year is the only reliable way to confirm which substances must be reported.
References & sources
Primary regulatory documents and authoritative references underpinning this answer.