Other issues

You must also think about spill clean-up equipment, non-dangerous goods, and situations involving small quantities of hazardous chemicals when managing incompatible hazardous chemicals.

Selecting fire fighting agents

It is important that you consider the appropriate fire suppression needs for each of the hazardous chemicals at your workplace. Incompatible fire fighting agents will make an emergency situation worse.

The safety data sheet (SDS) for each material needs to be consulted for the appropriate type of fire fighting media that is required. The first digit in the HAZCHEM code provides emergency responders with information about the most appropriate fire fighting medium to use.

Selecting appropriate spill clean-up equipment

When cleaning up spills, make sure the equipment you use does not react with the spilled material.

Separating other items from hazardous chemicals

Hazardous chemicals must not come into contact with foodstuff, food-packaging materials, items for direct personal contact and medical or veterinary products. A segregation distance of 5m between hazardous chemicals and these products is recommended.

You must not keep hazardous chemicals above food or other products or open containers of these chemicals in the same room.

Storing hazardous with non-hazardous chemicals

When storing hazardous chemicals, it is important to also consider that adverse reactions can arise between these and other materials that are not hazardous. Some examples of incompatibility between hazardous chemicals and common products include:

• metals that react adversely with some corrosive chemicals (e.g. strong acids) to give off flammable hydrogen gas
• aqueous (water containing) solutions (e.g. detergents) can react adversely with dangerous when-wet substances (e.g. calcium carbide) to give off flammable and or toxic gases and heat
• combustible products (e.g. saw dust, paper, timber products, asphalt, organic fibres) can react with oxidising agents
• organic peroxides that react violently even with small traces of zinc, copper, iron, combustible materials and other contaminants.

Storing small quantities of hazardous chemicals

There are times where it may not be practicable to store smaller and aggregate quantities of hazardous chemicals apart by 3m or more (e.g. retail places, laboratory work benches and cabinets).

However you must still manage the risk from incompatible goods. Incompatible goods must not be stored either vertically or horizontally on the same shelves.

Control measures may include:

• segregate goods using a liquid tight partition between incompatible materials
• segregate incompatible materials in different fire-rated, self-bunded chemical storage cabinets
• store incompatible materials on different shelves to ensure they do not come into contact
• store glass bottles on lower shelves to minimise breakage
• ensure liquid goods are not placed above solids and powders.