Many substances pose serious risks to human health or the environment in relatively low quantities.
In 1999, Environment Canada and the NPRI Multistakeholder Ad Hoc Work Group on Substances examined candidate substances for addition to the NPRI and at alternate reporting thresholds. The following changes were made to the NPRI for the year 2000. The 20 000-hour employee threshold was removed for facilities used for wood preservation and certain types of incineration. The consultations leading to these changes and the reporting criteria for the substances with alternate reporting thresholds are described in detail in the Supplementary Guide and on the NPRI Web site .