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These guidelines provide practical advice for investigating and addressing complaints and notifications about poisoning arising from chemical contamination of the environment and hazardous-substances injury.
The Hazardous Substances and New Organisms Act 1996 (HSNO Act) refers to injury, but for practical purposes, this also includes disease associated with exposure to a hazardous substance that is legally required under the Health Act 1956 and the HSNO Act 1996. The guidelines contribute to the assessment of human health risk or health impact by providing a systematic procedure for responding to and investigating chemical or hazardous substance complaints and notifications.
The guidelines are for public health officers who investigate complaints of chemical or hazardous-substances injury, and notifications of poisoning arising from chemical contamination of the environment (referred to as chemical exposure incidents) in non-occupational settings. People may be exposed in non-occupational settings in and around home or outdoors.
These guidelines should also be used whenever a hazardous-substance injury in an occupational environment is notified to the National Public Health Service.
The guidelines provide advice on coordination with other agencies, such as regional councils, territorial authorities, Environmental Protection Authority, WorkSafe New Zealand, and the Ministry of Business, Innovation and Employment (Trading Standards).
The guidelines are designed to be compatible with investigations carried out by these agencies.
The 2026 revisions are minor and administrative only. They include the updated WorkSafe notification form in Appendix 3. This form is to be used when medical officers of health notify WorkSafe of work-related notifiable diseases or hazardous substances injuries under section 199 of the Health and Safety and Work Act 2015. Links to other publications have also been updated.