Composites Design and Manufacture (Plymouth University teaching support materials) Health and Safety

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Go direct to Product Data Sheets and Material Safety Data Sheets or Fibres - Health and Safety
Safety in Manufacturing Plastics and Composites

The Health and Safety Executive have an online COSHH Essentials webpage.
The University of Reading - Plant Sciences website has a useful online COSHH Chemicals database.

Styrene - see Reduction of styrene in the environment and the workplace

Fibres - health and safety

"There is debate about the hazards associated with glass fibre but currently none of the other [acrylic or polyester] reinforcements are known to be harmful" [1].

The Health and Safety Executive (HSE) have adopted threshold limit values (TLV) for man-made mineral fibres during an 8-hour time-weighted average (TWA) exposure of:

• 10 mg/m³ for total dust
• 5 mg/m³ for respirable dust

These control limits correspond to the TLVs for nuisance dust. Care should be taken during the handling of reinforcements to ensure that these levels are not exceeded. Atmospheric monitoring and control measures may be required. General methods for dust sampling are outlined by the HSE [2]. Where exposure to fibre dust cannot be reduced by control measures (dust suppression or local exhaust ventilation), then suitable respiratory protective equipment should be provided [3, 4].

Broken fibres may cause irritation to sensitive areas of skin. Personal cleanliness, keeping dry and careful working habits are the best ways to prevent skin irritation. The use of a barrier cream, talcum powder or protective clothing (which does not induce perspiration) can be helpful. Thorough washing and rinsing should remove loose filaments [5]. Irritation of the upper respiratory tract is also possible. Fibres of <3μm diameter and <200μm length are classified as respirable [6].

aramid

A report [7] from DuPont research has suggested that lung tumours can occur in rats exposed to aramid fibres at concentrations over 250 times that in a typical composites workplace. No specific reactions were recorded at lower densities. Dr John Davis of the Institute of Occupational Medicine noted that the rat inhalation studies "were only possible because great ingenuity was used to break up the material and to keep it airborne" [8].

carbon

Carbon fibres are electrically conductive and can cause electrical hazard and equipment failure. Electrical equipment should be located remote from potential carbon fibre contamination, should be constructed to be immune to carbon dust, or special procedures (positive pressure of filtered air) must be adopted [5, 9]

SUMMARY

The use of fibrous reinforcements in industry should be quite safe, but prudent factory management should always include frequent counts of respirable fibre levels to ensure that they remain low. No factory should use fibrous materials without routine checks on the levels of respirable fibres generated. If the levels of respirable fibres are negligible, then the health hazards should be negligible as well.

REFERENCES

1. A guide to health and safety in GRP fabrication, HSE Guide C35, December 1987. ISBN 0-7176-0294-X. #4.
2. General methods for the gravimetric determination of respirable and total dust, HSE Methods for the determination of hazardous substances 14, ISBN 0-7176-0142-0.
3. Certificate of approval (RPE), HSE, 1983 revised F2 486.
4. Recommendation for the selection, use and maintenance of RPE, British Standard BS 4275, 1974.
5. Handling precautions - Health and Safety at Work Act 1974, Carrfibre datasheet - Handling precautions, September 1985.
6. Man-made mineral fibres, HSE Discussion Document, July 1979. ISBN 0-11-883251-4.
7. C Barrie, DuPont aims to calm cancer fears over Kevlar, The Engineer, 19 November 1987, 265, 6-7.
8. JMG Davis, Private communication, 27 May 1988.
9. Carbon dust: health and safety precautions, HSE Environmental Health Guidance Note EH21, January 1979. ISBN 0-11-883181-X.