Hazard Vehicle safety systems
Knowledge and understanding
|Vehicle safety systems||
Understand all associated hazard knowledge
The hazards presented by vehicle safety systems include:
- Heat from vehicle components
- Physical injury from fast-moving vehicle components
- Noise from deployment of safety systems
- Skin irritation from powders or chemicals released from airbags
- Projectiles and explosives
Vehicle safety systems are designed to protect the occupants of the vehicle in certain types of accidents or collisions. They are installed in many types of road vehicles, but may be concealed or their presence and state unknown. Because of this, there is a risk that personnel could inadvertently deploy safety systems. This could result in injury to personnel, other emergency responders, or vehicle occupants.
Vehicle safety systems include:
- Supplementary restraint systems (SRS), comprising:
- Airbags, including inflatable tubular structures, inflatable curtains and side impact protection systems (SIPS)
- Seat belt tensioners
- Seat belt load limiters
- Roll over protection systems (ROPS)
Airbags are designed to work in conjunction with the seat belt system. Activation of passenger airbags may be determined by the presence of seat occupancy detectors.
In the event of a collision serious enough to cause injury, the airbag should inflate using either a propellant or compressed gas. If a propellant is used, the chemical reaction may produce heat and noise. Newer systems may use dual-stage gas generators in what are known as multi-stage airbags.
Within milliseconds the airbag emerges at approximately 200mph from its storage compartment, which is split apart and folded out of the way by the force of the inflation. Most airbags are made from a highly durable polyamide fabric, which is dusted with talcum powder to protect it and stop it sticking. When the airbag is deployed, this powder will form a white cloud. Small holes at the back of the airbag allow the cooled gas to escape.
People with allergies or asthma may experience a reaction to the chemicals generated when an airbag deploys, mainly if there is prolonged exposure to the chemicals.
Seat belt pretensioners
Seat belt pretensioners normally deploy in tandem with airbags. They reduce the slack in the seat belt by up to 15cm. These devices, if undeployed, present a trap hazard that could cause injuries. Seat belt tensioners may be activated by a gas cartridge. Crimping or crushing the gas cartridge may cause it to release at high pressure, creating a hazardous projectile.
Roll over protection systems ROPS
Roll over protection systems (ROPS) are found in some convertible vehicles, and are deployed automatically in the event of the vehicle rolling over. If activated, roll over bars will be deployed within a fraction of a second, at great force and high speed. If ROPS are present and have not been deployed, there is a risk of injury to personnel, other emergency responders and vehicle occupants if they activate. It is not always apparent as to which direction the roll over bars will travel if activated.
- Control measureUse specialist cutting equipment
- Control measureIdentify the vehicle safety systems and communicate the information