Dangerous goods quick reference guide regarding flammable substances and outlining dos and don’ts on handling those Class 4 cargoes.
Class 4 dangerous goods include flammable solids and substances that can ignite spontaneously or emit flammable gases when in contact with water. These pose risks such as property damage, cargo damage, injury, environmental harm, insurance invalidation, and potential criminal prosecution.
Classification and examples
- 4.1 Flammable Solids: Self-reactive, polymerising substances, and solid desensitised explosives. Examples: Aluminium powder, matches, sulphur, fire lighters, activated charcoal.
- 4.2 Spontaneously Combustible Substances: Liable to ignite without external ignition. Examples: Phosphorus, sodium sulphide, fishmeal, carbon, oily cotton waste.
- 4.3 Dangerous When Wet: Emit flammable gases when in contact with water. Examples: Calcium carbide, sodium, potassium.
Do’s and Dont’s
Packing
Do…
- Use only approved packaging for Class 4 cargoes
- Ensure appropriate packaging for each division (air tight for 4.2 and water tight for 4.3
Don’t…
- Use damaged packaging
- Repackage Class 4 cargoes without specialist advice
Storing
Do…
- Store in well-ventilated and, where required, temperature-controlled storage facilities (self reactive and polymerising)
- Store with labels forward, heavy cargoes at bottom, and correct orientation (arrows up)
- Inspect stored cargoes regularly to ensure condition remains stable and safe
- Alert the dangerous goods competent person immediately if any problems
- Ensure all employees involved in storing are trained in emergency response procedures
Don’t…
- Store near to stairways and emergency exits
- Store near to sources of heat, such as a radiator
- Store near to sources of ignition, such as electrical equipment and (for Class 4.3) water
- Store near other cargoes that are designated incompatible
- Store old or uncollected cargoes, which can become more unstable over time
Transporting
Do…
- Ensure all relevant transport risks assessments are up to date
- Ensure all staff involved in transport have the relevant dangerous goods awareness training
- Contact the DG competent person if you have any questions or queries about transport
- Pack cargoes securely to avoid movement during transport
- Familiarise yourself with and adhere to the relevant chapters of the CTU Code
- Where required use temperature-controlled transport units (self-reactive and polymerising)
Don’t…
- Allow any ignition sources near cargoes during transport
- Transport Class 4.1 cargoes if classed as ‘high consequence’ without a security plan in place
REMEMBER
Always:
- Communicate clearly with the entire supply chain
- Follow the manufacturer’s instructions
- Maintain a documented emergency response plan that is regularly tested and, ideally, developed in collaboration with the cargo manufacturer
Never:
- Expose flammable solid cargoes to extreme temperatures
- Throw, drop, roll, slide or drag Class 4 cargoes at any point in the supply chain
- Ignore abandoned cargo – it must be safely removed and disposed of