Plastics - Frequently asked questions


Will styrene used in plastics manufacturing damage my health?

Styrene is widely used in the plastics industry. Styrene vapour can cause irritation to the nose, throat and lungs. Other symptoms can include difficulty in concentrating, drowsiness, headaches and nausea. The vapour and splashes are also irritating to the eyes and skin.

It is not possible to specify a 'safe' level to which employees can be exposed without a risk to their health. The work exposure limit (WEL) for styrene is currently 100 parts per million (ppm) averaged over an 8-hour day. There is also a short-term exposure limit (STEL), currently 250 ppm averaged over a 15-minute period. Employers should carry out assessments to identify what control measures are needed to reduce exposure to below these levels.

Provided that adequate controls are put in place to reduce exposure, there should be no damage to people's health from the styrene in resins.

For more information on controlling styrene, see: Assessing and controlling styrene levels during contact moulding of fibre-reinforced plastic (FRP) products .

Are the fibres in the grinding of Glass Reinforced Plastic (GRP) hazardous?

Dust produced from grinding GRP can cause fluid to collect on the lungs, respiratory irritation and skin irritation.

There is no work exposure limit (WEL) specified specifically for exposure to GRP. However, there is a WEL specified for nuisance dust of 10 mg/m3 averaged over an 8-hour day, which would apply to GRP dust.

Employers should carry out assessments to determine what control measures are appropriate for grinding GRP. Possible control measures include the use of gloves / overalls etc to protect skin, good hygiene procedures to remove dust, and local exhaust ventilation (LEV) to prevent it being inhaled. You should also train and inform your staff of the hazards of GRP dust, the symptoms to be aware of if exposed, and what action to take if exposure occurs.

For more information on carrying out assessments, see: COSHH.

How can we reduce hand knife injuries?

Hand knives are used widely in the plastics sector and can account for a significant proportion of injuries in individual companies. However, these injuries can be reduced in a number of ways:

  • Firstly, determine if you have to use hand knives. See if you can change tooling or processes to eliminate the use of hand knives
  • Ensure you select and provide the right knife for the task
  • Ensure that the right type of blades are provided and that maintenance regimes are followed
  • Provide appropriate personal protective equipment (PPE) for the task
  • Assess the environment to see if there are environmental factors present that could increase the likelihood of injuries (eg poor lighting, slip hazards etc)
  • Provide training to staff to ensure they are using hand knives correctly and using the correct PPE etc

For more information, see: How to reduce your hand knife injuries.

How can I do machine interventions such as mould changing / maintenance safely?

Before you intervene in a machine, whether carrying out maintenance, repairs or changing tooling, you should first work out your safe system of work (SSoW). The SSoW should be completed following a risk assessment and should consider issues such as:

  • proper isolation
  • permits to work
  • electrical hazards
  • mechanical hazards
  • what props may be needed to prevent mechanical parts moving under gravity
  • procedures to release stored energy before working on them
  • other hazards associated with the task, such as work at height, asbestos etc
  • restoring the machine to its normal operating equipment (eg replacing fixed guards, ensuring interlocks are working properly)

Once you have assessed the risks and devised your SSoW, you should make sure staff are properly trained and provided with the necessary equipment to carry out the task safely.

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Updated 2023-09-13