Motor Vehicle Repair Industry

Occupational Health in The Motor Vehicle Repair Sector

Posted By Kerry Budworth on 2015-08-22 18:46

Occupational Health Surveillance in The Motor Vehicle Repair Industry

There have been over 7000 injuries and 33 deaths in the motor vehicle repair (MVR) industry over the last 5 years according to the HSE website. Because of the nature of the materials used, there is widespread potential for work-related ill health in MVR body shops. Many of the substances used require careful storage, handling and control. It makes sense to have a strong occupational health strategy to protect your employees and your business. 

Occupational health strategy

Because of the nature of the MVR industry there is a need for a cross surveillance approach in any occupational health surveillance strategy. By that we mean that employees should be monitored for multiple conditions as part of your strategy. There should be lung function testingbiological monitoring for isocyanates exposure and dermatological surveillanceThis surveillance monitors employees for the occupational diseases and problems that most feature in the MVR industry. The diseases are occupational asthma, occupational dermatitis and exposure to isocyanates. 

Isocyanates & occupational asthma

In particular, isocyanate-containing paints have been the biggest cause of occupational asthma in the UK. The MVR industry is also in the top 10 industry's for cases of disabling dermatitis. Paints containing isocyanate are used extensively in MVR as almost all motor vehicle repair body shops use 2-pack or "2K" isocyanate-containing paints. Isocyanates are also used in some water-based paints, most base coats and almost all lacquers. It is important that you are aware that water-based does not mean isocyanate-free. It just means that it is an emulsion based paint and has reduced levels of solvents.

The spraying of 2-pack isocyanate paints is the main cause of occupational asthma in the UK.  Paint sprayers in the industry have about a 90 times higher risk of getting asthma compared with the rest of the UK working population. According to the figures on the HSE website, every year around 50 sprayers are diagnosed with isocyanate asthma and most have to leave the industry.

It is not just a problem for paint sprayers, other workers in body shops are also sometimes affected. There have been cases of maintenance personnel, managers and others who work in close proximity to spray booths/rooms getting isocyanate asthma. This spray mist containing isocyanate may also worsen existing asthma. Once people are affected even very low exposure levels can trigger an attack. Significant skin contact with isocyanate hardeners may cause dermatitis.

Over a number of years HSE have worked with representatives from the MVR industry to explode the myths and explain why even the best air-fed visor can fail to protect people. Below are some key tips for vehicle paint sprayers and owners of motor vehicle repair body shops.

Vehicle paint sprayers

  1. The risk of developing occupational asthma occurs because paint spraying produces a lot of invisible airborne mist that you can breathe in. Never spray paint outside the spray booth or room.
  2. Your spray booth/room takes time to clear of mist, so know the clearance time and make sure that everyone else does too.
  3. Always wear air-fed breathing apparatus (BA) when spraying and know how to safely leave or enter your booth or room during the clearance time.
  4. Your employer should check the controls are working by measuring your exposure to isocyanate. Currently the only way to do this (and accepted by the MVR industry) is by providing a urine sample for analysis. See Sector Information Sheet 03/2012/01 - Reducing ill health from isocyanate exposure in motor vehicle repair (MVR)
  5. You need regular health surveillance i.e. lung function testing and skin checks. This is to identify early symptoms and signs of occupational asthma and dermatitis (skin rashes).

Body shop owners / managers

  1. Spraying 2-pack isocyanate paints creates fine, invisible, airborne mist that can cause occupational asthma
  2. It spreads through the air like smoke.
  3. Your spray booth or room takes time to clear of fine paint mist.
  4. Measure the clearance time (information below) using a smoke/fog generator, clearly mark it on the entrance door(s) and make sure everyone who uses the booth/room knows what to do. For information on smoke generators and advice on how to conduct a clearance time measurement please see Measuring paint spray booth clearance time.
  5. The research report 'An automated system for indicating spray clearance times of MVR spray booths and rooms - RR742' describes the design and assembly of a device consisting of a timer switch, programmed with the clearance time, which is triggered by a sensor that detects when the spray gun is turned on and off. Two types of sensor are evaluated and recommendations made for different operational setups. The system is relatively inexpensive and can be retrofitted to existing spray booths/rooms.
  6. Make sure the booth/room runs at slight negative pressure so that if there are any leaks, air is drawn into the booth/room rather than paint mist leaking out into the workshop
  7. Make a list of simple daily and weekly checks to be done in the booth/room, appoint someone to do them, record the findings and act if things are wrong
  8. Check exposure is properly controlled by arranging for the analysis of urine samples of vehicle paint sprayers. See Sector Information Sheet 03/2012/01 - Reducing ill health from isocyanate exposure in motor vehicle repair (MVR)
  9. Arrange regular health surveillance for those potentially exposed to isocyanate paints such as sprayers. For more information on health surveillance for occupational asthma see HSE guidance publication'Health surveillance for occupational asthma (G402)'
  10. Use the COSHH paint spraying and allied tasks and other published advice to help you reduce exposures to isocyanates.

Measuring paint spray booth clearance time

Knowing how long it takes for your spray booth/room to clear of fumes is an important factor in your occupational health strategy. The HSE has guidelines to measure the clearance time using a party fog machine or professional smoke machine. They recommend that the test should be undertaken just before the filters in the spray booth or room are changed. This allows you to assess a worst-case time. It is recommended that a clearance time test should also be included in the 14-month thorough maintenance examination of the booth or room. The guidance is as follows:

  1. The spray booth or room should be empty when measuring the clearance time. This is because the volume of the car will effectively reduce the volume of a booth or room and give a lower clearance time. In addition, the smoke generated is made of a glycol aerosol and may leave a greasy deposit on any vehicle or body part in the booth/room.
  2. The booth or room should be set up for normal spraying operations except with the ventilation deactivated (see No. 3) and the lights on maximum to enable the smoke aerosol to be seen.
  3. Ensure that the extraction system is turned off. There are two reasons for this:
    1. in a booth with the ventilation running it would be very difficult to fill the room completely;
    2. Filling the booth with the extraction turned off will give a clearance time showing the worst case scenario ensuring the room is clear before anybody enters, or sprayers remove their RPE.
  4. Fill the room with smoke, making sure to distribute smoke evenly throughout the room (an extension lead may be useful in allowing all areas of the room to be reached).
  5. The room shall be regarded as full when the facing wall is no longer visible when viewed across the short axis of the room. Depending on the fog machine used, it may cut out and require time to reheat one or more times before this is achieved.
  6. Switch on the ventilation system and start a timer.
  7. During the smoke test the opportunity should be taken to do a visual inspection of the exterior of the booth and any associated ductwork to check for any leaking air.
  8. The room shall be regarded as clear when smoke is no longer visible in any part of the room. A lamp (viewed from a narrow angle towards the beam of light) may be useful in judging this, though ensuring that the room is truly full at the start of the measurement is more important than precise judgement of when the smoke has cleared. The difference between clear by eye and clear using a lamp is typically 30 seconds longer.
  9. Note the time at which the room is judged to be clear of smoke. This time should be rounded up to the next quarter minute. This should be put on a notice and displayed on the door or entrance of the booth or room, and all personnel who need to know should be told.

Occupational health surveillance 

As an occupational health services provider HealthScreen UK can supply health surveillance services across the United Kingdom including biological monitoring, dermatology surveillance and lung function testing in the workplace. If you have any questions or you would like a quote, please don't hesitate to contact us on 01455 234 600 or online. 

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