National Environment Protection Measures
The National Environment Protection Measures (NEPM) are a nationally consistent approach to assessing site contamination.
Under legislation, there are specific definitions, extraction methods and reporting fractions for hydrocarbon analyses of samples from contaminated sites.
NEPM defines how the concentration of each fraction is determined, for example:
- Fraction 1 includes all the hydrocarbons eluting (elution is closely correlated to boiling point) between n-hexane (C6) and n-decane (C10) with the sum of benzene, toluene, ethylbenzene and xylenes (BTEX) compounds subtracted.
- Fraction 2 is calculated as the difference between the >C10–C16 fraction and naphthalene; the concentration of naphthalene is derived from the volatile total recoverable hydrocarbons (TRH) analysis (purge and trap GC-MS).
Our capabilities
The National Measurement Institute is Australia’s peak measurement body. We offer:
- a personalised service
- competitive pricing
- full analytical reports tailored to meet your requirements.
Our testing services
You should request the NEPM TRH–silica test when you suspect samples contain significant levels of non-petroleum based interferences. For instance, trade waste or soils with high organic content. The report from this test includes the semi-volatile fractions from >C10–C40.
Limits of reporting
These are the minimum concentration that we can be reliably detected in our laboratories.
| TRH | NMI method | Limit of reporting for soil (mg/kg) | Limit of reporting for water (µg/L) |
|---|---|---|---|
| TRH C6–C10 | NGCMS_1121 | <25 | <25 |
| TRH C6–C10 less BTEX (F1) | NGCMS_1121 | <25 | <25 |
| TRH >C10–C16 | NGCMS_1112 | <50 | <25 |
| TRH >C10–C16 less Naph (F2) | NGCMS_1112 | <50 | <25 |
| TRH >C16–C34 (F3) | NGCMS_1112 | <100 | <100 |
| TRH >C34–C40 (F4) | NGCMS_1112 | <100 | <100 |
How to request a services from NMI
Read the steps to request an environmental testing and analytical service and how to send samples from in Australia or from overseas.