Respiratory protection (lungs)
One of the most important hazards faced by the bodyshop
worker is that of potential damage to the lungs.
Respirators are usually needed in body repair shops
even though adequate ventilation is provided for the
working areas. During welding, metal or paint preparation,
or spraying, some form of protection is necessary.
Under the COSHH Regulations, respiratory
protection is essential and therefore must be used.
Respirators give protection against abrasive dusts,
gases, vapours from caustic solutions and solvents,
and spray mist from undercoats and finishing paint,
by filtering the contaminated atmosphere before it is
inhaled by the wearer. They may be either simple
filtering devices, where the operator’s lungs are used
to draw air through the filter, or powered devices
incorporating a battery-driven fan to draw contaminated
air through the filters and deliver a flow of
clean air to the wearer’s face. There are four primary
types of respirator available to protect the bodyshop
technicians: dust respirators, cartridge filter respirators,
powered respirators, and constant-flow air line
breathing apparatus.
Dust respirators (masks)
The most basic form of respiratory protection is the
disposable filtering half-mask, typically used when
preparing or finishing bodywork such as by rubbing
down or buffing, and where dust, mist and fumes are
a problem. This face mask provides an excellent
face seal while at the same time allowing the wearer
to speak freely without breaking the seal. Breathing
resistance is minimal, offering cool and comfortable
use. Various types of mask are available for use in a
variety of environments where contaminants vary
from nuisance dust particles to fine dusts and toxic
mists. These masks can only be used in atmospheres
containing less than the occupational exposure limit
of the contaminant (Figure 2.6a, b).
Cartridge filter mask
The cartridge filter or organic vapour type of respirator,
which covers the nose and mouth, is equipped
with a replacement cartridge that removes the
organic vapours by chemical absorption. Some of
these are also designed with a pre-filter to remove
solid particles from the air before the air passes
(a) (b)
Figure 2.6(a) Dust mask (b) Dust mask in use (Racal Safety Ltd )
64Repair of Vehicle Bodies
through the chemical cartridge. They are used in
finishing operations with non-toxic paints, but not
with isocyanate paints. For the vapour/particle respirator
to function correctly it is essential that it fits
properly against the face. Follow the manufacturer’s
instructions for changing the cartridges when spraying
over a continuous period (Figure 2.7a, b).
Powered respirators
Powered respirators using canister filters offer
protection against toxic dusts and gases. The
respirator draws contaminated air through filters
with a motor fan powered by a rechargeable
battery and supplies clean air to the wearer’s
face. This avoids discomfort and fatigue caused
by the effort of having to inhale air through
filters, permitting longer working periods. These
devices find great use both in the spray shop and
in the repair shop when carrying out welding
(Figure 2.8a, b).
Constant-flow air line breathing apparatus
The constant-flow compressed air line breathing
apparatus is designed to operate from an industrial
compressed air system in conjunction with the
spray gun. Using a waist-belt-mounted miniature
fixed-pressure regulator and a pre-filter, the equipment
supplies breathing quality air through a
small-bore hose to a variety of face masks and
visors to provide respiratory protection for paint
spraying (such as with isocyanates), cleaning and
grinding (Figure 2.9a, b). The COSHH Regulations
have made it mandatory for all respiratory protection
equipment to be both approved and suitable
for the purpose, for the operatives to be correctly
trained in the equipment’s use and maintenance,
and for proper records to be kept.
Ear protection
The Noise at Work Regulations 1989 define three
action levels for exposure to noise at work:
1 A daily personal exposure of up to 85 dB(A).
Where exposure exceeds this level, suitable
hearing protection must be provided on request
(Figure 2.10).
2 A daily personal exposure of up to 90 dB(A).
Above this second level of provision, hearing
protection is mandatory.
3 A peak sound pressure of 200 pascals (140 dB).
Where the second or third levels are reached,
employers must designate ear protection zones
and require all who enter these zones to wear ear
protection. Where the third level is exceeded, steps
must be taken to reduce noise levels as far as is
reasonably practicable. In every case where there is
(a)
(b)
Figure 2.7(a) Standard cartridge mask with filters
(Racal Safety Ltd ) (b) Cartridge mask and protective
coveralls being used while spraying (Gramos
Chemicals International Ltd )
Health and safety 65
a risk of significant exposure to noise, assessment
must be carried out and action taken to minimize
hearing damage.
The first two noise action levels relate to exposure
over a period (one day) and are intended to cater for
the risks of prolonged work in noisy surroundings.
The third level is related to sudden impact noises
like those occurring in metal working procedures.
2.2 Fire precautions
The Fire Precautions (Places of Work) Regulations
1992 replaced and extended the old Fire Precautions
Act 1971 as from 1 January 1993. These Regulations
are aligned with standard practice in EC
Directives in placing the responsibility for compliance
on the employers. They require employers not
only to assess risks from fire, but now to include the
preparation of an evacuation plan, to train staff in
fire precautions, and to keep records. Workplaces
with fewer than 20 employees may require emergency
lighting points and fire warning systems. The
self-employed who do not employ anyone but
whose premises are regularly open to the public
may only require fire extinguishers and warning
signs; they will, however, need to be able to demonstrate
that there is a means of escape in case of fire.
Where five or more persons work on the premises as
employees, all assessments need to be recorded in
writing.
Most of these requirements were already covered
by existing legislation. The prime differences are
the recording of assessments, the provision of training,
and the requirement that means of fighting fire,
detecting fire and giving warning in case of fire, be
maintained in good working order.
(a) (b)
Figure 2.8(a) Airstream welding helmet (powered respirator) (b) Powered respirator in use in welding
(Racal Safety Ltd )
66Repair of Vehicle Bodies
2.2.1 What is fire?
Fire is a chemical reaction called combustion (usually
oxidation resulting in the release of heat and
light). To initiate and maintain this chemical reaction,
or in other words for an outbreak of fire to
occur and continue, the following elements are
essential (Figure 2.11):
Figure 2.10Ear protectors (Racal Safety Ltd )
(a) (b)
Figure 2.9(a) Visionair constant-flow breathing apparatus (b) Operator wearing complete constant-flow
breathing apparatus (Racal Safety Ltd )
Figure 2.11The fire triangle (Chubb Fire Ltd )
Health and safety 67
Fuel A combination substance, either solid, liquid
or gas.
Oxygen Usually air, which contains 21 per cent
oxygen.
Heat The attainment of a certain temperature
(once a fire has started it normally maintains its
own heat supply).
Methods of extinction
Because three ingredients are necessary for fire to
occur, it follows logically that if one or more of
these ingredients is removed, fire will be extinguished.
Basically three methods are employed to
extinguish a fire: removal of heat (cooling);
removal of fuel (starving); and removal or limitation
of oxygen (blanketing or smothering).
Removal of heat
If the rate of heat generation is less than the rate of
dissipation, combustion cannot continue. For
example, if cooling water can absorb heat to a
point where more heat is being absorbed than generated,
the fire will go out.
Removal of fuel
This is not a method that can be applied to fire
extinguishers. The subdividing of risks can starve a
fire, prevent large losses and enable portable extinguishers
to retain control; for example, part of a
building may be demolished to provide a fire stop.
The following advice can contribute to a company’s
fire protection programme:
1 What can cause fire in this location, and how
can it be prevented?
2 If fire starts, regardless of cause, can it spread?
3 If so, where to?
4 Can anything be divided or moved to prevent
such spread?
Removal or limitation of oxygen
It is not necessary to prevent the contact of oxygen
with the heated fuel to achieve extinguishment. It
will be found that where most flammable liquids
are concerned, reducing the oxygen in the air from
21 to 15 per cent or less will extinguish the fire.
Combustion becomes impossible even though a considerable
proportion of oxygen remains in the atmosphere.
This rule applies to most solid fuels although
the degree to which oxygen content must be reduced
may vary. Where solid materials are involved they
may continue to burn or smoulder until the oxygen
in the air is reduced to 6 per cent. There are also
substances which carry within their own structures
sufficient oxygen to sustain combustion.