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

2.2 Information on exposure
The manufacture of stainless steels gives rise to airborne dusts and fumes and thus
presents the potential for inhalation exposure in the occupational setting. The
components of the airborne dusts and fumes are likely to vary according to the type of
production process, the stage of the process and also according to the grade of
stainless steel under production. Airborne substances may arise from the metal
constituents used to produce the stainless steel, such as oxides of chromium, nickel,
iron, molybdenum and manganese. Available information indicates that airborne dust
contains chromium predominantly as Cr III , although Cr VI compounds do occur
(Huvinen et al. 1993; Koponen et al. 1981a). Other substances present in the
atmosphere may contain the following elements: silicon, calcium, aluminium,
magnesium and sodium (Koponen et al. 1981a). From the available data, it is
difficult to characterise the type of exposure that occurs at each stage of the
manufacturing process more precisely.
With regard to polycyclic aromatic hydrocarbons (PAHs), former methods of stainless
steel manufacture involved the use of electrodes which may have given rise to
airborne PAHs during the melting stage. Modern methods of manufacturing stainless
steel use electrodes which do not release PAHs during melting, and thus there is no
exposure to PAHs during this stage of the production process. PAHs may occur
during the casting stage if molds are used which contain binders and additives,
airborne PAHs arising as decomposition products of these materials. However,
currently most stainless steel is cast using the continuous casting process; this process
involves water-cooled copper molds and PAH exposure is therefore not anticipated.
Although there is the potential for inhalation exposure in the stainless manufacturing
industry, the quantitative data on exposure are limited. Two reports have been
published; both studies are based on the same company in Finland. The results from
these studies are summarised in Table 2.1. The UK Health and Safety Executive
(HSE) were unable to provide any additional exposure data relating to the
manufacture of stainless steel.
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