Hazardous substances rules apply to a much wider range of New Zealand workplaces than the phrase suggests. Cleaning products, fuels, LPG, paints, solvents, adhesives, pool chemicals, agrichemicals and compressed gases are all captured, which brings in workshops, salons, cafés, gyms, farms and cleaning contractors alongside obvious industrial sites.
The framework
Hazardous substances are approved and controlled by the Environmental Protection Authority under the HSNO regime. Workplace requirements sit in regulations under the Health and Safety at Work Act and are enforced by WorkSafe.
The practical effect is that a business has obligations both about the substance itself and about how it is used in the workplace.
The baseline obligations
Inventory. You must keep a current inventory of hazardous substances at the workplace, recording what they are, their classification, maximum quantities held, and where they are located. It must be readily accessible, including to emergency services.
Safety data sheets. An SDS must be available for each hazardous substance, current and accessible to workers. Suppliers must provide them; keeping them is your obligation.
Labelling and packaging. Substances must be correctly labelled. Decanting into an unlabelled container is one of the most common breaches and a genuine cause of harm.
Information, training and supervision. Workers must know what they are handling, what the risks are, what controls apply and what to do in an emergency.
Emergency response. Depending on substances and quantities, requirements can include emergency response plans, spill containment, fire extinguishers and eyewash or shower facilities.
The threshold-based obligations
Above defined quantities, further requirements attach:
- Certified handlers. Certain substances require a person with a current certified handler compliance certificate to be present or in control.
- Location compliance certificates. Locations where specified substances are held above thresholds require certification, renewed periodically.
- Signage identifying hazards at entry points.
- Secondary containment to contain spills and prevent environmental discharge.
- Separation distances between incompatible substances and from ignition sources and boundaries.
- Tracking for the highest-hazard substances, recording their location and movement.
The thresholds are substance-specific. A business needs to know not just what it holds but how much, because crossing a threshold changes the obligations without anyone being notified.
Health monitoring and exposure
Where workers are exposed to substances that can cause harm through repeated exposure, exposure monitoring and health monitoring may be required. Isocyanates, solvents, silica, welding fume and certain agrichemicals are common triggers.
This is an area of increasing regulatory attention, because the harm is chronic and appears years later. Businesses that have never considered occupational health — as distinct from safety — should look at what their people actually breathe.
Where businesses get caught
- No inventory. The single most common finding, and the easiest to fix.
- Not realising ordinary products are captured. Bulk cleaning chemicals in a commercial kitchen are hazardous substances.
- Quantities creeping over a threshold without the associated certificates being obtained.
- Expired location compliance certificates, treated as one-off rather than cyclical.
- Decanted and unlabelled containers.
- Incompatible storage — oxidisers with flammables, acids with bases — usually because storage grew organically.
- Contractors bringing substances on site that are not on your inventory and not in your emergency plan.
A practical starting sequence
- Walk the site and list every chemical product, including in vehicles, sheds and cleaning cupboards.
- Collect a current SDS for each and read the classification.
- Record maximum quantities held and compare against the thresholds.
- Identify what triggers certified handler, location certificate or tracking requirements.
- Fix labelling and segregation, which is usually quick and cheap.
- Write the emergency response information and make sure it and the inventory are accessible at the point emergency services would arrive.
WorkSafe publishes a hazardous substances calculator and detailed guidance free at worksafe.govt.nz, and the EPA publishes the register of approved substances and their controls. Both are free, and the calculator answers the threshold question faster than reading the regulations.
General information only, not legal advice.
