16 June 2016

Certification of Stationary Container Systems for Hazardous Substances

If you’re involved in designing stationary container systems for hazardous substances, make sure you’re aware of the processes for certification. Take a look at this guidance from WorkSafe New Zealand.

The starting point for the certification of stationary container systems which contain hazardous substances is Schedule 8 of the Hazardous Substances (Dangerous Goods and Scheduled Toxic Substances) Transfer Notice. Clause 92 of this Schedule 8 specifies the requirements, in particular clause 92(2)(b) specifies the elements that need to be verified in order to achieve certification. There are also some exemptions to certification specified in clause 1 of Schedule 8 and in the relevant individual clauses of this Schedule 8.

Stationary container systems can comprise stationary containers (stationary tanks, process vessels) and associated equipment (pipework, fittings, dispensers etc).

For an installation which is new to industry, the broad elements which must be certified include the stationary container design, the stationary container construction/fabrication and the installation (which includes pipework and ancillary items (eg pumps dispensers etc.)). Each of these broad elements include specific requirements, such as pressure management, emergency pressure management, level indicator and lightning protection.

Stationary Tanks

For purposes of certification, stationary tanks which contain hazardous substances are divided into two categories: field constructed and shop fabricated. Field constructed includes tanks which are constructed on site but also includes tanks which are “one off” ie it may be fabricated in a workshop as a one-off tank. Shop fabricated refers to tanks which are fabricated in a workshop on a regular basis to the same design.

A field constructed tank must have all elements certified on an individual basis by a test certifier(s) approved for all of these elements. This includes design, construction and installation.

A tank which is shop fabricated may have the tank design certified and entered onto the Tank Design and Fabricators Register. The fabricator certified to fabricate that design may also be entered onto the register. In this case, once the tank arrives on site, it is only the installation which must be certified for that site.

The EPA guidance document Certification of Stationary Tanks and Process Containers elaborates on the process and indicates the certifier in question may rely on documentation prepared by a chartered engineer or the constructor. See Appendix B of this document for a flow chart of the processes.

Test Certifiers

Stationary container systems are required to be certified by a certifier(s) approved for the respective elements ie design/construction/installation. A list of approved test certifiers is maintained by the Environmental Protection Authority. Use the following steps to ascertain which of these persons is approved for the stationary system in question: 1. In the first of the two search boxes change “all types” to “stationary container systems”. 2. In the second search box either leave as “all regions” or select the region desired. 3. Complete the search. 4. Click on the names of the individuals. The detailed approval of each person is listed together with their limitations.

There are different types of approvals for test certifiers, even just for stationary container systems which contain hazardous substances. As a general rule there are fewer test certifiers approved for design and construction/fabrication. The approval held by a certifier may also be limited by size of tank. A certifier may be approved to certify for design and construction/fabrication but may be limited to tanks of a specified capacity eg 60,000 litres. You should discuss your requirements with the certifier to make sure he/she holds an approval which encompasses your requirement.

For more information or assistance, email WorkSafe at hsinfo@worksafe.govt.nz