WOOD DUST: HAZARDS AND PRECAUTIONS
Introduction
This Information Sheet is one of a series prepared by the HSE's Woodworking National Interest Group (NIG). Wood dust consists of tiny particles of wood produced during processing and handling of wood, chipboard, hardboard etc. It can be harmful to health and can explode with disastrous results.
The control of wood dust is required by law
- Health and Safety at Work etc Act 1974 ISBN 0 10 543774 3
- Factories Act 1961 ISBN 0 10 850027 6
- Control of Substances Hazardous to Health Regulations 1988 ISBN 0 11 087657 1
The main operations likely to produce high dust levels in the woodworking industry are:
1 machining operations, particularly sawing, routing and turning;
2 sanding, by machine and by hand; and
3 using compressed air lines to blow dust off furniture and other articles before spraying.
High airborne dust levels can also occur during the bagging of dust from dust extraction systems and during factory cleaning, especially when compressed air lines are used for blowing dust from walls, ledges and other surfaces.
What are the hazards?
Health
Too much dust of any kind can adversely affect health. Wood dust is no exception. Exposure has been associated with the following health problems:
1 skin disorders;
2 obstruction in the nose;
3 a type of asthma; and
4 a rare type of nasal cancer.
The Control of Substances Hazardous to Health Regulations 1988 (COSHH) {Control of Substances Hazardous to Health Regulations 1988 ISBN 0 11 087657 1
CONTROL OF CARCINOGENIC SUBSTANCES. CONTROL OF SUBSTANCES HAZARDOUS TO HEALTH REGULATIONS 1988. HSC COP 29 ISBN 011 885468 2} came into force on 1 October 1989 and, by virtue of Regulation 6(1), an assessment (normally written) should be made of risks to health associated with wood dust, together with any action needed to prevent or control those risks.
Regulation 7(1) goes on to say that exposure to both hardwood and softwood dust should be prevented, or where this is not reasonably practicable, adequately controlled.
Hardwood dust has been assigned a maximum exposure limit (MEL) of 5 mg/mÀ3Ù (8-hour time-weighted average) in Schedule 1 of the Regulations and therefore exposure by inhalation to hardwood dust should be reduced so far as is reasonably practicable and, in any case, below the MEL. Detailed guidance on the health effects of hardwood dust and the precautions required are given in HSE leaflet HARDWOOD DUST. {HARDWOOD DUST 1990 HSE IND(S)21(L) revised}
Softwood dust has not been allocated an occupational exposure limit under the COSHH Regulations but the HSC's Advisory Committee on Toxic Substances intends to review exposure to the substance. However, pending the outcome of this review, the limit of 5 mg/mÀ3Ù (8-hour time-weighted average) for softwood dust in Table 4 of HSE Guidance Note EH40 OCCUPATIONAL EXPOSURE LIMITS, {OCCUPATIONAL EXPOSURE LIMITS 1990 HSE Guidance Note EH 40 ISBN 0 11 885420 8 (revised annually)} should be used as guidance for the control of exposure under Regulation 7(1).
Fire/explosion
Each year premises and plant are severely damaged or destroyed by wood dust fires and explosions. Concentrations of small dust particles in the air can form a mixture that will explode if ignited. These concentrations usually occur in dust extraction equipment which can be destroyed unless special precautions are taken. Such an explosion can also dislodge dust deposits that may have accumulated on walls, floors and ledges which in turn can ignite causing a secondary explosion.
Wood dust will also burn readily if ignited. Fires can be started by badly maintained heating units, overheated electric motors, electric sparks and sparks from other sources such as open wood burning stoves and cigarettes.
Safety
Wood dust on the floor can cause tripping or slipping. Vision can be impaired by airborne chips and dust generated during machining and sanding operations.
Precautions
Health
If exposure to wood dust cannot be prevented altogether, then assess the risk to health from exposure to airborne dust by:
1 finding out if exposure to dust is being adequately controlled in your workplace. A dust lamp can be used to show up the dust and where it is coming from; {FURNITURE AND WOODWORKING: HEALTH AND SAFETY 1977 HSE ISBN 0 11 883224 7}
2 where necessary carrying out dust measurements which should be made by the recommended method. {GENERAL METHODS FOR THE GRAVIMETRIC DETERMINATION OF RESPIRABLE AND TOTAL INHALABLE DUST HSE MDHS 14 revised 1989 ISBN 071 76 0343 1} Your trade association should be able to give advice on organisations which can do this work; and
3 determining whether workers will be exposed to airborne dust levels in excess of the occupational exposure limit;
Exposure to airborne dust may be adequately controlled by:
1 using a process or method of work that reduces the generation of dust to a minimum;
2 providing dust control equipment to all dust producing processes to stop the dust entering the workroom atmosphere, {FURNITURE AND WOODWORKING: HEALTH AND SAFETY 1977 HSE ISBN 0 11 883224 7} eg local exhaust ventilation at woodworking machines; and
3 making sure that plant and equipment is properly maintained. {THE MAINTENANCE, EXAMINATION AND TESTING OF LOCAL EXHAUST VENTILATION HSE HS(G)54 1990 ISBN 0 11 885438 0} Keep ventilation ducts free from blockages and repair broken or damaged ducts. Maintain filter units and other plant and equipment regularly in accordance with the manufacturer's recommendations and COSHH.
Where measures taken to reduce exposure to airborne dust are inadequate, then in addition to taking those measures suitable respiratory protective equipment will be necessary. {RESPIRATORY PROTECTIVE EQUIPMENT: A PRACTICAL GUIDE FOR USERS HSE HS(G)53 1990 ISBN 0 11 885522 0}
It should be selected from equipment that is type-approved by HSE or complies with the appropriate HSE approved standards. {RESPIRATORY PROTECTIVE EQUIPMENT: LEGISLATIVE REQUIREMENTS AND LISTS OF HSE APPROVED STANDARDS AND TYPE APPROVED EQUIPMENT 1990 HSE ISBN 0 11 885428 3}
- Provide other personal protective equipment, such as eye protection, overalls and gloves, where necessary. Make sure it is suitable and kept in good order. Launder overalls and aprons regularly.
- Provide good washing facilities with hot and cold water, soap and towels and encourage a high standard of personal hygiene.
- Provide vacuum cleaning equipment to remove dust from clothing, where this is a problem. Prevent the use of compressed airlines.
- Make sure workers are adequately instructed, trained and supervised. This is essential if they are to understand the precautions and their duties and responsibilities.
Fire/explosion
- Check that the design and installation of dust control equipment incorporates explosion precautions. {FURNITURE AND WOODWORKING: HEALTH AND SAFETY 1977 HSE ISBN 0 11 883224 7 DUST EXPLOSIONS IN FACTORIES HSE HSW 22 revised 1976 ISBN 0 11 880851 6} In particular look at location of collection equipment, the need for enclosure and/or explosion relief.
- Keep floors free and clear from wood chips and dust. Pay particular attention to areas around machines and on or near heating units.
- Clean inside walls, ceilings, ledges and other surfaces of workrooms regularly to prevent dust accumulating. Use suitable vacuum cleaning equipment. Do not use compressed airlines as this will create dust clouds and redistribute the dust.
Reading list and references
1 Health and Safety at Work etc Act 1974 ISBN 0 10 543774 3
2 Factories Act 1961 ISBN 0 10 850027 6
3 Control of Substances Hazardous to Health Regulations 1988 ISBN 0 11 087657 1
4 CONTROL OF CARCINOGENIC SUBSTANCES. CONTROL OF SUBSTANCES HAZARDOUS TO HEALTH REGULATIONS 1988. HSC COP 29 ISBN 011 885468 2
5 HARDWOOD DUST 1990 HSE IND(S)21(L) revised
6 OCCUPATIONAL EXPOSURE LIMITS 1990 HSE Guidance Note EH 40 ISBN 0 11 885420 8 (revised annually)
7 FURNITURE AND WOODWORKING: HEALTH AND SAFETY 1977 HSE ISBN 0 11 883224 7
8 GENERAL METHODS FOR THE GRAVIMETRIC DETERMINATION OF RESPIRABLE AND TOTAL INHALABLE DUST HSE MDHS 14 revised 1989 ISBN 071 76 0343 1
9 THE MAINTENANCE, EXAMINATION AND TESTING OF LOCAL EXHAUST VENTILATION HSE HS(G)54 1990 ISBN 0 11 885438 0
10 RESPIRATORY PROTECTIVE EQUIPMENT: A PRACTICAL GUIDE FOR USERS HSE HS(G)53 1990 ISBN 0 11 885522 0
11 RESPIRATORY PROTECTIVE EQUIPMENT: LEGISLATIVE REQUIREMENTS AND LISTS OF HSE APPROVED STANDARDS AND TYPE APPROVED EQUIPMENT 1990 HSE ISBN 0 11 885428 3
12 DUST EXPLOSIONS IN FACTORIES HSE HSW 22 revised 1976 ISBN 0 11 880851 6
13 AN INTRODUCTION TO LOCAL EXHAUST VENTILATION HSE HS(G)37 1987 ISBN 0 11 883954 3
14 DUST IN THE WORKPLACE: GENERAL PRINCIPLES OF PROTECTION HSE Guidance Note EH 44 ISBN 0 11 883598 X
15 DUST CONTROL AT WOODWORKING PROCESSES HSE Specialist Inspector Report No 14
This information is reproduced from a leaflet published by the Health and Safety Executive
This page is sponsored by Professional Health and Safety Consultants Ltd. Phone Internationally: +44 2087787838 or UK London 020 8778 7838 for all your health and safety requirements.