While diesel is not a particularly flammable substance, it is an environmental hazard with considerable clean-up costs if it should leak into a drain, watercourse or the soil.

Diesel is a hazardous substance and two grades of diesel fuel are approved for use in New Zealand:

  • automotive gas oil and marine diesel
  • low flash point diesel

For simplicity, both are treated as flammable liquids, low hazard.

In addition, diesel may be blended with biodiesel in quantities up to 99 percent biodiesel. The biodiesel is non-hazardous but the blends are treated as flammable liquids, low hazard. As a flammable liquid, low hazard diesel will burn, but not as easily as a flammable liquid, such as petrol.

Safe use of diesel

Adhere to the following safety guidance when using or storing diesel:

  • No hotwork should be performed on the storage tank or container unless it is emptied and purged of remaining diesel vapour.
  • Containers should be positioned away from any source of direct heat.
  • Drums should be located in an area where there is no risk of collision with vehicles, such as fork-lift trucks, as diesel splashing onto a hot engine may ignite.
  • Leaks and spills should be confined to the vicinity of the drum and mopped up quickly, to lessen the risk of slipping.
  • Adhere to safe handling practices when refilling and dispensing containers.

Storing diesel

Diesel does not require a Location Compliance Certificate or a certified handler. When stored in a bulk storage tank of more than 5,000 litres, a Stationary container compliance certificate is required. This is also the case if the diesel is used in connection with an oil burning installation or an internal combustion engine, such as a generator. In this case, the threshold could be as low as 60 litres. There are exceptions where the diesel is used in a domestic oil burning installation.

Diesel may be kept in a store room in a building, but the store room must have a fire resistance rating and the quantities allowed are limited, as is the package size.

Storing diesel on farms

The rules are slightly different for diesel stored on farms of more than four hectares.

Above ground fuel storage on farms (PDF 4.3 MB)

While this guidance has not been updated to reflect current work health and safety legislation (the Health and Safety at Work Act 2015 and regulations), it may still contain relevant information and practices to keep workers and others healthy and safe.

Please read this guidance in conjunction with all relevant industry standards that apply to you as a PCBU. This guidance will be progressively reviewed and either updated, replaced with other guidance, or revoked.