manufacture, processing and use of stainless steel - International ...

Grinding of stainless steel
Airborne dust from grinding of stainless steel is made up of spinels and therefore has
a different chemical composition and metallurgical structure to that of metallic
stainless steel. A proportion of the airborne dust particles are respirable and therefore
grinding operations present the potential for inhalation exposure in the occupational
setting. Grinding activities frequently accompany welding operations and also occur
during the later stages of stainless steel manufacture.
Data on the acute toxicity of grinding dust from stainless steel are limited to a single
animal intratracheal (i.t.) instillation study which simply showed that a suspension of
grinding dust (up to 112 mg/kg) was non-lethal in hamsters.
Animal data on the effects of repeated exposure are limited to a single study. Effects
on body weight occurred with repeated i.t. instillation of up to 9 mg dust (total of 12
doses administered at 14-day intervals); information regarding other effects was not
available and it was not possible to identify a NOAEL. No human data are available
concerning the effects of repeated exposure to grinding dust.
Data from two i.t.-dosing carcinogenicity bioassays provide no evidence for the
carcinogenicity of grinding dust from stainless steel, with two austenitic grades and
one ferritic grade failing to induce lung tumours.
Two available studies of cancer risks in grinders of stainless steel do not indicate that
such work leads to excess risks of lung cancer. One study reported cancer findings
under broad headings rather than for individual cancer sites. Nevertheless, it provided
no support for the hypothesis of an effect on cancers of the colon and rectum
suggested by the other study.
When data concerning the hazards of grinding dust from stainless steel are evaluated
against the current EU classification criteria, no concern would appear to be raised in
relation to any of the toxicological end-points.
According to the available data, there appears to be no identifiable hazard associated
specifically with grinding dust from stainless steel. Nevertheless, as some of the
airborne dust is respirable and thus presents the potential for inhalation exposure, it
appears appropriate to treat grinding dust as any other kind of dust and to control
exposure to the appropriate exposure limit 3 .
Although there are gaps in the toxicological database for grinding dust, there appear
to be no major concerns for health and therefore no further testing is warranted.
Cutting of stainless steel
Cutting of stainless steel may be performed using mechanical, laser or plasma cutting
methods. Plasma cutting performed in the open atmosphere appears to be the only
method which presents the potential for inhalation exposure in the workplace.
3 3 3
In the UK, the occupational exposure limit for dust is 10 mg/m (total inhalable dust) or 4 mg/m
(respirable dust).
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