Moves are under way to close big gaps in tracking the volume and type of hazardous chemicals getting into the environment.
The Environmental Protection Authority is asking for submissions on a move to require annual reporting from importers and manufacturers.
This follows criticism by Parliamentary Commissioner for the Environment Simon Upton of the country's "disjointed and patchy" system for tracking chemicals.
The EPA's move would initially cover agricultural and domestic pesticides, fumigants, timber treatment chemicals, parasiticides used as veterinary medicines, antifouling paints, starting in March 2026, and may be expanded later. Any amount would have to be reported - there would be no minimum.
Companies would also have to let the authority know a lot more about the nature of the chemicals, which would help officials in turn inform companies about new problems or rules around the substances.
Upton has said the country has no way of quickly finding in out what is being used and where, if there is a pollution emergency.
A similar EPA attempt eight years ago was dropped after pushback from submitters concerned about their ability to provide this information and extra administration, and the authority had not tried since.
"Other regulators internationally have established systems to collect information" but New Zealand did not, the authority said in its new 53-page discussion document.
For instance, Australia, Canada and the EU collected pesticide information each year from companies.
Companies in New Zealand are by law required to notify the EPA the first time they import or manufacture a hazardous substance, but the authority is worried they do not.
"Improving compliance with the notice is essential to the current regulatory system," the report said.
The new proposal would have non-reporting incur an infringement notice and a fine.
The key would be how much active ingredient is in the product. "Our expectation is that importers and manufacturers will know the concentration of the active ingredients in their products and will therefore have this information available."
The EPA also proposes to report to the public each year in an aggregated way.
It is also proposing tightening up on report-backs about explosives made in New Zealand.