A tank that is installed in a building as part of an installation for burning a class 3.1 substance or substance approved by the Environmental Protection Authority (EPA) is required to comply with requirements of Regulation 17.57 of the Health and Safety at Work (Hazardous Substances) Regulations 2017.

A stationary tank must be designed and constructed to ensure that if the tank is located in a building, the hazardous substance does not discharge or leak from any part of the stationary container system within that building, and any vent pipe, relief valve or overfill pipe must terminate outside the building. The exception to this is a SwRI 95-03 tank, which can have an emergency vent that terminates inside the building.

Where an emergency vent terminates inside a building, a PCBU cannot rely on sighting liquid coming out from the vent pipe that is located outside the building as this will mean that liquid will also be coming out of the emergency vent within the building.

Operational requirements for all stationary tanks

Regulation 17.65(2)(a)(iii) requires that when a stationary tank that is part of a system is being filled, the filling must be monitored to prevent over-filling. Regulation 17.11(1) requires that a PCBU must ensure a tank is not filled with a hazardous liquid to a level that exceeds the safe fill level. In practice this means they should have some form of over-fill protection in place.

Clause 5.3.3 of AS1940:2017 provides reasonably practicable steps that could be implemented to prevent a stationary tank from being overfilled, but a PCBU is not limited to these. The PCBU must ensure that whatever overfill protection system is used is fit for purpose and remains functional for the life of the tank.

Ensure a person filling the tank checks the overfill protection system is working before the tank is filled.