The key hazards and risks are indicated by the dangerous goods classification on the label of the container.
When assessing risk for stored chemicals, consider the following:
-The quantity of chemical to be stored and the type of containers (i.e in packages or in bulk)
-The duration of storage
-The dangerous goods class, Packing Group and other characteristics of the chemicals with respect to toxicity, stability and compatibility (see the MSDS or supplier)
-The separation of chemicals from other classes of dangerous goods. For example, Class 5 oxidising agents, such as solid pool chlorine, are incompatible with many other substances
-Spillage control (for liquids)
-Fire rating of the structure and walls
-Emergency procedures and equipment needed in the store (consult the MSDS for information on fires and other emergencies)
-The need for control of potential ignition and heat sources
-Separation from other stores of chemicals, fuels or combustible materials
-Separation distances from other activities and accommodation.
-Separation distances, the isolation of spills and suitable emergency procedures are important control measures even when small quantities of chemicals are stored for short periods.
Even small amounts of highly toxic chemicals in packages, such as dangerous goods in Packing group I (eg carbon disulphide), should be stored in a metal cabinet.
Relatively small amounts of PG II or III should be kept on impervious spill trays on shelves.
Some veterinary chemicals should be kept in a refrigerator, separated from food.
You should use a designated storage area for chemicals if storing more than 100 kg or L. This may be a cabinet, part of an existing store or a purpose-built store.
Reducing the quantity of chemicals stored is one of the most cost effective ways of reducing the risk.
Many chemicals have a specified shelf life and do not retain their efficiency beyond that date. Minimising purchasing not only saves purchasing costs but also minimises disposal costs.
Storage design (solids or liquids)
When storing chemicals, consider using a secure separate building, or a segregated area within a building, with the following features:
-Cross flow ventilation
-Concrete floors with drainage into a sump
-Concrete door sills
-Concrete block or concrete walls to a suitable height to provide a bund
-Impervious shelving or spill control trays on shelving
-A lockable door to keep dangerous goods secure, or child-proof latch if no dangerous goods are stored
-A clean-up kit for spills
-Access to water for washing and cleaning.
Provision must be made for the containment of spills of those chemicals classified as dangerous goods
(OHS Regulation clause 174Y). This is also good practice for those chemicals not classified as dangerous goods.
The walls (or bund) and door sill should be high enough to contain a spillage of 25 per cent of the total volume of packaged liquid chemicals, including at least 100 per cent of the largest package.
All above-ground bulk tanks must have a form of spillage control (also called bunding). Bunding for bulk tanks under a roof must contain 100 per cent of the largest tank, or 110 per cent for outside tanks (to allow for possible rain water accumulation). A bulk tank includes a bulk transport container such as an IBC (Intermediate Bulk Container).
Provide for drainage of spills and clean up water into a sump or pit that can contain the chemical, clean up materials and the wash water. A supply of wash water should be readily available.
Good natural cross-flow ventilation should be provided with vents in opposite walls, above bund height.
Substances should be stored at a cool temperature to prevent deterioration. The products should be protected from moisture so that packing and labelling does not deteriorate (especially cardboard containers).
Check the MSDS for information on chemical compatibilities and other advice in relation to storage. In some cases, specific Australian Standards provide advice on the location, design and separation distances of the store.
If you store relatively large quantities of chemicals (eg more than one tonne or more than 1,000 L of any type) then a specific Australian Standard may need to be observed.
The storage and handling of agricultural and veterinary chemicals should be observed if you have more than 1,000 kg or 1,000 L of agricultural chemicals that are dangerous goods.
In some cases where a wider variety of packaged dangerous goods are used (eg where produce is processed such as wineries or oil extraction) AS/NZS 3833 The storage and handling of mixed classes of dangerous goods in packages and intermediate bulk containers may be applicable.
The above standards are approved industry codes of practice.