Hazardous Substances in NZ Workplaces — HSWA 2015 & HSNO Act 1996

If your workplace stores, handles, or uses any hazardous substance — from cleaning chemicals to industrial solvents — you must comply with two overlapping laws: the Health and Safety at Work Act 2015 (HSWA) and the Hazardous Substances and New Organisms Act 1996 (HSNO). This guide explains your key duties in plain English, with exact section numbers, so you can keep your team safe and stay on the right side of WorkSafe.

1. The Legal Framework

HSWA sets the general duty to manage risks (s36 – PCBU duty to ensure health and safety, so far as is reasonably practicable). HSNO adds specific rules for hazardous substances, including the Hazardous Substances (Hazardous Property Controls) Notice 2017 (HPC Notice). Together they require you to identify hazards, control exposure, and have emergency plans.

2. Safety Data Sheets (SDS)

You must have a current Safety Data Sheet for every hazardous substance in your workplace (HPC Notice, Part 2, cl 2.1). The SDS must be from the supplier (or manufacturer) and less than five years old. Keep them accessible to all workers — a physical folder or a digital portal works. Staff must know where to find them and how to read the hazard statements (H‑phrases) and precautionary statements (P‑phrases).

3. Labelling

Every container of a hazardous substance must be labelled with the product name, hazard pictograms, signal word, H‑phrases, P‑phrases, and supplier details (HPC Notice, Part 3, cl 3.1). For decanted substances (e.g., a spray bottle of degreaser), the label must include the product name and the relevant hazard pictograms — at minimum. Never use unlabelled containers; that’s a breach of cl 3.5.

4. Storage Segregation

Incompatible substances must be separated to prevent dangerous reactions. Follow the NZS 8134:2021 standard (especially clause 2.7) for storage of flammable liquids, oxidisers, and corrosive substances. For example:

• Flammable liquids (Class 3) must be stored away from oxidisers (Class 5.1) by at least 3 metres, or in a dedicated flammable cabinet.
• Corrosives (Class 8) must be segregated from flammable liquids and toxic substances.
• Use bunded pallets or spill containment trays for liquids.

Check the SDS for specific incompatibility data. A simple segregation chart on the wall helps staff remember.

5. Personal Protective Equipment (PPE)

PPE is the last line of defence — you must first try to eliminate or isolate the hazard (HSWA s36). Where residual risk remains, provide suitable PPE at no cost to workers (HPC Notice, Part 4, cl 4.1). Common requirements:

• Gloves: check breakthrough time for the specific chemical.
• Eye protection: safety glasses or goggles for splash risks.
• Respiratory protection: if airborne contaminants exceed exposure limits (WES values).

Train staff on correct use, storage, and disposal of PPE. Replace damaged items immediately.

6. Spill Response

You must have a spill response plan that covers containment, clean‑up, and disposal (HPC Notice, Part 5, cl 5.1). Keep spill kits accessible near storage and handling areas. The kit should include absorbent materials, neutralisers (for acids/alkalis), PPE, and disposal bags. Train staff on the plan and run drills annually.

7. WorkSafe Notification Thresholds

Some workplaces must notify WorkSafe if they hold certain quantities of hazardous substances. Under the HPC Notice, Schedule 7, you must notify if you have:

• More than 100 litres of flammable liquids (Class 3.1A or 3.1B)
• More than 50 kg of toxic substances (Class 6.1A or 6.1B)
• Any amount of explosive substances (Class 1)

Check the full schedule for your substances. Notification is done via the WorkSafe Hazardous Substances Online Notification system. Keep a copy of your notification on site.

If you’re unsure about your obligations, your team can ask ShiftScript questions directly from your uploaded policies at shiftscript.nz/portal/ — it’s like having a compliance expert on demand.

8. Training and Supervision

All workers who handle or are near hazardous substances must be trained (HSWA s44 – duty to provide information, training, and supervision). Training should cover:

• How to read SDS and labels
• Safe handling and storage procedures
• Emergency response (spill, fire, first aid)
• PPE selection and use

Document training records and refresh them at least every two years, or when a new substance is introduced.

9. Record Keeping

Keep the following records for at least five years (or longer if required by HSNO):

• Current SDS for each substance
• Hazardous substances inventory (updated annually)
• Spill and incident reports
• Training records
• WorkSafe notification (if applicable)

An up‑to‑date inventory helps you quickly identify risks and respond to emergencies.