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ZHHealth and safety in the factory – part 1
Examining some key aspects that affect employee health and safety, and detailing the best practice for different areas of production.
All employers have a legal duty of care for their employees, including satisfying health and safety legislation. Failure to do so may result in fines or the imprisonment of directors and managers. However, ensuring that members of staff are well protected from hazards will have a significant and measurable impact on the success of a company in a number of other ways:
- the number and severity of accidents will be reduced, contributing to more efficient production and also reducing healthcare costs
- well-protected workers will be more content and, therefore, more likely to remain loyal. Such retention of skills will reduce training costs and increase efficiency of production
- good health and safety practices form a significant part of an overall ethical trading policy and companies seen to look after their employees will attract more business.
Many hazards are present
No production processes can be exempt from consideration, although some will be more potentially hazardous than others. Many aspects are common to a number of areas, while some will be process-specific.
The majority of hazards in a particular area should be easily identifiable. Nevertheless, not every hazard will be immediately obvious and determining the corrective action might not be straightforward. Expert guidance may be required to identify all the hazards in any particular work area, determine how shortcomings should be addressed and assess the level of improvement required. Factory management should monitor these on a regular basis to ensure standards are maintained.
The best method of monitoring hazards is to carry out regular ‘risk assessments’, and thereby develop means of reducing these. In many jurisdictions risk assessments are a mandatory part of health and safety legislation.
Airborne hazards
Perhaps the most obvious hazard in many production areas where solvent-based adhesives and primers are used is that of volatile organic compound (VOC) concentrations (see box 1). Not only are many of these toxic, but also many are flammable and, therefore, potentially explosive. The best long-term solution is to substitute all solvent-based products with solvent-free alternatives, although availability, cost and current factory practices may act as deterrents in this regard.
| Box 1: Examples of recommended maximum solvent (VOC) exposure levels | |
| Chemical | Workplace exposure limit (WEL) |
| Acetone Ammonia Cyclohexane Dichloromethane Ethyl acetate MEK (butin-2-one) Toluene |
500 25 100 100 200 200 50 |
| Note: these levels are listed in the International Chemical Safety Card (ICSC) system, supported by the International Labour Organisation (ILO), the World Health Organisation (WHO), the United Nations Environmental Programme (UNEP) and the European Union (EU). These values are expressed in parts per million (ppm) over an eight-hour period. | |
An acceptable alternative is to prevent solvent vapours from building up to hazardous levels around work areas. This strategy can involve several approaches:
- good design of work areas can minimise vapours in workers’ ‘breathing zones’ (see the photograph at the top of this page)
- special safety dispensers can reduce vapour emissions from the products used
- efficient extraction can remove vapours as they are produced. This must not, however, be confused with ventilation or air circulation measures.
Another option is to issue workers with breathing apparatus. Any issue of personal protective equipment (PPE) must always be considered the last resort and masks should not just be absorptive – proper respirator masks are required to fully protect operatives. Above all, smoking or naked flames must be prohibited wherever solvent-based products are used.
Solvent stores and mixing rooms
In solvent storage, bulk dispensing and mixing areas the risk is more acute, albeit for shorter exposure times. The use of PPE is advisable here, even with the necessary extraction systems. Masks, therefore, are frequently worn in adhesive mixing rooms.
Extreme measures are required to prevent explosion of flammable vapours. All electrical switches, lighting and mixing systems must be non-sparking types. It is also prudent to ban mobile phones and other personal electronic equipment in such areas, as these may provide sources of ignition.
Spillage containment measures must be in place where large volumes of solvent-based products are stored. Sand or another absorbent and inert medium should be available to prevent spillage spread. Raised ridges or steps will more effectively contain spillages (these are known as ‘bunded areas’) and thereby prevent flow to other areas. Indeed, the storage/mixing area should be capable of being sealed off completely until vapours clear. Adequate fire hazard and health warnings should be sited outside this area and a self-actuating dry powder sprinkler system should be installed.
Electrical dangers
As well as the special fixtures required in solvent stores, other aspects of electrical supply require attention. All machines that draw power should be checked regularly for electrical safety, and a notice attached to indicate when testing is next due. These checks should be made at least annually and also whenever repairs have been made to the equipment. Machines that fail such checks should be disconnected until they are repaired and retested. Full records must be kept of all testing and repairs.
A visual check should also be made to ensure fittings are sound and undamaged. Any worn or damaged wiring must be replaced by a competent and qualified electrician. All electrical connections on machines must be insulated to prevent contact with live wires.
Electrical wires and leads should be as short as possible and flex should never lie across floors (figure 1). Not only are these tripping hazards but, if knocked, they could become loose and ‘live.’ Also – as in solvent stores – safety electrical fittings must be used wherever flammable materials are at risk of ignition by sparks or electrical arcing.
Figure 1: Trailing flexes and hoses pose very severe tripping hazards
Fire precautions
There should be a responsible person assigned as ‘fire warden’ or ‘fire marshal’ for each work area. Deputies must also be assigned to cover for absences. Suitable extinguishers should be readily to hand and clearly marked for the type of fire on which they should be used. If extinguishers are not immediately visible, signs must indicate where they are located. The extinguishers must be checked regularly, as should fire hoses and hydrants. They must also be mounted in accessible positions.
There should be sufficient numbers of easily accessible alarm sounders located around all occupied buildings, with a considerable number in higher-risk areas. As mentioned previously, this is best determined by conducting risk assessments in each area. Alarm sounders need to be tested regularly with fire drills, for which records should be kept. In noisy environments, sounds can be supplemented with flashing lights.
In the event of a fire or drill, any problems encountered by staff must be reported and recorded – for example, if exit routes are blocked or doors are locked. It is also important to ensure that all walkways, emergency routes and passages are free of tripping hazards and blockages. They should be sufficiently well marked and wide enough to allow easy access for members of staff.
Fire routes and exits must never be used as storage areas (even on a temporary basis) and employees must not leave personal items in these areas. They must also not be used as rest or break areas.
Floor surfaces must be sound, even, free of contamination and have an acceptable level of slip resistance. Good levels of slip resistance are particularly important on ramps and slopes.
Dust and particulates
Figure 2: Dust exposure can be determined by personal air monitors
Airborne particles are commonly produced by roughing and scouring operations. These should be treated in the same manner as vapours. Fine particulates and smoke also emanate from some moulding and vulcanising operations, and can be checked by personal air monitors (figure 2). It is important to ensure that extraction equipment is of sufficient power to remove dust particles. Local exhaust ventilation (LEV) systems must produce sufficient air movement to capture released particles near the workstation.
Noise levels
As with solvent vapours, the best strategy is prevention rather than cure (box 2). Can noisy machines be replaced with quieter alternatives? Could a machine be modified to reduce noise? Sometimes effective maintenance and lubrication can be equally effective.
| Box 2: Noise levels |
SATRA recommends two ‘action levels’:
|
Noise levels can change as machines wear, as new machines are added and also when different combinations of machines are in use. Therefore, noise monitoring should be carried out at regular intervals – and certainly when replacement or new machines are brought into operation.
If a noisy operation or area is unavoidable, workers should wear ear protectors. Noisy machines and the areas housing them should carry notices telling workers to wear hearing protection. At high noise levels, ear protection should be mandatory. Consideration should be given to collecting together and screening off noisy operations from other production areas, to minimise the number of workers affected.
Part 2 of this article will investigate such issues as factory lighting levels, mechanical hazards, safe manual handling, ergonomic factors and what to do in the event of an injury.
How can we help?
Please contact us at healthandsafety@satra.com for further information on how to develop an effective health and safety programme.
Publishing Data
This article was originally published on page 10 of the September 2019 issue of SATRA Bulletin.
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