WorkSafe’s Hazardous Substances Calculator helps New Zealand workplaces create a hazardous substances inventory and identify many of the key controls that may apply. Before you begin, gather a current safety data sheet (SDS) for each substance, the maximum amount likely to be at your workplace, where it is stored, and any storage or segregation requirements. The calculator is a useful starting point, but it does not replace the legislation or cover every possible control.
In the video below, WorkSafe demonstrates how to create an inventory, add substances, review the controls and incompatibilities the calculator identifies, and keep the results up to date.
Before you start
Use the information on your SDS to prepare for the calculator. WorkSafe says a current SDS, or a condensed version of its key information, must be kept with the inventory and be readily accessible to people who may handle or be exposed to the substance, including emergency services.
- Check that you have an SDS for every hazardous substance in the workplace. Your supplier must provide a compliant SDS when the substance is supplied, including when it is first supplied after five years or after the SDS has changed. WorkSafe’s SDS guidance explains the requirements.
- Record the maximum amount likely to be at the workplace, not just what is on site today.
- Note where each substance is stored and any specific storage or segregation requirements.
- Keep the relevant SDS sections handy: Section 2 for classifications, Section 7 for handling and storage, Section 10 for stability and reactivity, Section 14 for the UN number, and Section 15 for regulatory information such as an approval number or group standard.
1. Accept the disclaimer and create an inventory
Start by reading and accepting the calculator’s disclaimer. It explains what the tool does and does not cover. From the landing page, choose Create a new inventory.
- Choose whether the inventory is for substances in closed containers or open containers. If your workplace has both, create two separate inventories.
- Give the inventory a name that will make sense to the people who maintain it.
- Record the unique PIN immediately. The calculator saves the inventory online for future use, but WorkSafe cannot retrieve the PIN for you. You can also use the calculator’s email option to send the PIN to yourself.
The information entered into the calculator is private, and the inventory can be opened again only with its PIN. Keep the PIN where the people responsible for updating the inventory can access it.
2. Add each hazardous substance
Select Add a Substance and enter the product information from the SDS. For common substances such as petrol, diesel and LPG, searching by name may find the substance. For many branded products, search instead using the hazardous substance approval number from Section 15 of the SDS. If applicable, you can also search by the group standard named in Section 15.
- Enter the name you use for the substance at work, such as its brand name.
- Add the UN number from Section 14 when one is available.
- Enter the storage and segregation information relevant to your workplace using Sections 7 and 10.
- Select the substance’s location.
- If the calculator asks for classifications, enter every applicable classification from Section 2. If you do not know the classifications but the substance has a UN number, enter the UN class and packing group.
- Complete the remaining fields with information that reflects how the substance is actually held and used at your workplace.
Accurate classification and quantity information matters because the controls shown by the calculator depend on the substances and amounts you enter.
3. Review the inventory and controls
After a substance is added, the inventory appears on the left and the key controls appear on the right. Add the next substance and continue until the inventory is complete.
- Expand each inventory item to check the information entered.
- Look for incompatibilities between substances and any special rules highlighted by the calculator.
- Read the controls that apply to every hazardous substance and those triggered only above threshold quantities.
- Use the explanation beside each control to see why it applies and which substances triggered it.
Think of the calculator as a starting point. The linked practical guide contains more detailed information about how particular controls work and what your workplace may need to do.
4. Print or download the results
Select Print to open a print version containing the inventory followed by the control details. You can print a hard copy or save it as a PDF. The calculator also provides a Download option so you can save the inventory as a spreadsheet.
Keep the inventory readily accessible to emergency service workers during an emergency and after the workplace has been evacuated. WorkSafe’s inventory guidance explains what the inventory must contain and how it should be maintained.
5. Keep the inventory up to date
When you need to update the inventory, enter its PIN on the calculator landing page. You can delete a substance you no longer have, edit details such as its quantity, or add a new substance. The controls update when the inventory changes, so review the results whenever the substances, quantities or workplace arrangements change.
Quantity changes are especially important when a control is triggered by a threshold. After updating the inventory, download or print new copies so the workplace and emergency services have access to the current information.
What the calculator does not replace
The calculator provides key controls based on the information entered, but additional controls may apply to your workplace. Its disclaimer also notes that it does not cover every control under the regulations or HSNO, and it does not cover rules made by district, city or regional councils. Check the full requirements for your workplace, including any applicable emergency planning, signage, tracking, certification and training duties.
For the current tool and its own limitations, use the Hazardous Substances Calculator and refer to WorkSafe’s guidance on risk management.
Key takeaways
- Prepare your SDS, maximum quantities, locations and storage information before opening the calculator.
- Record the inventory PIN as soon as it is created.
- Enter full and accurate substance classifications wherever possible.
- Review incompatibilities, threshold-triggered controls and the practical guide.
- Update, print or download the inventory when your workplace changes.
