Dangerous substances

Dangerous substancesare any substances used or present at work that could, if not properly controlled, cause harm to people as a result of a fire or explosion. They can be found in nearly all workplaces and include:

• flammable liquids such as solvents, paints, varnishes and petrol;
• flammable gases, such as liquid petroleum gas (LPG);
• dusts from machining and sanding operations and dusts from foodstuffs.

Flammable liquids

What is the risk?

Accidental spills can cause fire or explosion. Flammable liquids should be used only for their intended purposes – using them for other purposes may lead to fires or explosions.

How to avoid the risk

If your employees are working with or near flammable liquids, you will need to explain:

• the basics of flammability;
• what to do if liquid is spilt;
• the dangers of using liquids, such as petrol, for cleaning machinery or starting bonfires;
• In garages, how to handle petrol safely.

Flammable gases

What is the risk?

Leaking gas from pipes, appliances or cylinders can cause fires or explosions.

How to avoid the risk

If your employees are working with or near pipes, cylinders or appliances containing flammable gases, you will need to explain:

• the basics of flammability;
• how to detect leaking gas;
• what to do in the event of a gas leak.

Gas cylinders

What is the risk?

Leaking gas from cylinders may cause fires or explosions.

Physical damage to cylinders may cause leaks which may lead to fires or explosions.

Heavy cylinders may cause injury if not properly handled.

Application of heat to gas cylinders may cause them to burst, possibly resulting in a ‘shrapnel’ type explosion. Alternatively the contents may be vented through a pressure release valve resulting in fire or explosion.

How to avoid the risk

If gas cylindersare used in your workplace, you will need to explain:

• the basics of flammability;
• how to detect leaking gas; and
• what to do in the event of a gas leak.

You should ensure that gas cylinders are properly handled, to avoid:

• the danger of fire or explosion; and
• the risk of physical injury to the worker, eg crushed toes.

You should ensure that gas cylinders are safely stored and used, away from direct sources of heat.

Acetylene cylinders, used in oxy/acetylene cutters, burners and welders is an extremely flammable gas and is different from other flammable gases because it is unstable. Special precautionsare required.

Work with vats, tanks, reservoirs or carboys containing chemical agents

What is the risk?

This work involves handling or working near to substantial quantities of substances hazardous to health.

There is a risk of fire or explosion where there is an explosive atmosphere, or where spills or leaks of flammable substances are readily foreseeable. There is also a risk of ignition if a flammable liquid splashes or soaks into clothing.

There is also a risk of falls from heights into dangerous substances.

How to avoid the risk

Your risk assessment should consider issues such as:

• how to ensure young people will follow emergency procedures properly if containment is lost;
• how to prevent young people from falling into tanks of hazardous chemicals; and
• how to ensure that young people behave responsibly when working near quantities of chemicals that have the potential to cause serious harm, eg making young workers aware of the dangers of introducing ignition sources in these situations.