Page 146 - Quick Guide to Welding and Weld Inspection by S.E. Hughes, Clifford Matthews

A Quick Guide to Welding and Weld Inspection

and then ignite, causing a flash fire or explosion. Oxygen is
particularly dangerous as it has no smell, but will cause a
flash fire to occur if an ignition source is brought into an
oxygen-rich atmosphere. In particular, if clothing is con-
taminated with oxygen, it will catch fire easily and burn very
fiercely, resulting in severe injury. Even fire-retardant
clothing will burn if contaminated with oxygen. Also, oxygen
can cause explosions if used with incompatible materials. In
particular, oxygen reacts explosively with oil and grease.
Most gases are stored under high pressure and gas
cylinders should be stored and used in accordance with
recognised practices. All fittings such as pressure regulators,
flashback arrestors, flowmeters, gas hoses, etc., should be
inspected at regular intervals and maintained in good
condition.
COSHH and workplace exposure limits (WEL)
The Control of Substances Hazardous to Health (COSHH)
Regulations require employers to prevent exposure to
substances hazardous to health, if it is reasonably practicable
to do so. If prevention is not reasonably practicable, the
employer must adequately control exposure by putting in
place measures including, in order of priority, one or more of
the following:
. Use processes that minimise the amount of material used
or produced, or equipment that totally encloses the
process.
. Control exposure at source (e.g. local exhaust ventilation)
and reduce the number of employees exposed to a
minimum, the level and duration of their exposure and
the quantity of hazardous substances used or produced in
the workplace.
. Provide personal protective equipment (PPE), e.g. face
masks, respirators, protective clothing, but only as a last
resort and never as a replacement for other control
measures that are required.

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Data Standards Ltd, Frome, Somerset – 17/9/200909QG Welding chap9.3d Page 130 of 134