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

grade was tested, an austenitic stainless steel (elemental composition: 9% nickel, 18%
chromium, 70% iron). Discs of the stainless steel were immersed in synthetic sweat
(pH 6.5) for six weeks at 30°C. The amount of nickel released during the first week
was approximately 0.04 µg/cm 2 /week; this decreased during the six-week period.
Discs made of the same type of stainless steel were also investigated in nickelsensitised
subjects in a human patch-testing study (see Section 1.1.4). The extent of
nickel release reported in this study is similar to the values reported for some of the
austenitic stainless steels by Haudrechy et al. (1994).
Ten items of stainless steel ear jewellery were investigated for release of nickel into
synthetic sweat (Fischer et al. 1984). The items were stored in synthetic sweat (pH
6.4) at room temperature for one week, after which the nickel content of the sweat
was determined. With eight items of jewellery, 0.05 - 3.0 µg Ni was released; with
the two other items of jewellery, 15 and 19 µg Ni was released. No details were
available regarding chemical composition of the stainless steel(s), nor the weight or
surface area of the items tested. This study therefore contributes little useful
information to this review of metallic stainless steel.
Nickel release into synthetic sweat from items of stainless steel jewellery was
quantified by Kanerva et al. (1994). Ten different “metal” items were investigated,
although only two of the items, two rivets, were reported to be made of stainless steel.
Each item was immersed in synthetic sweat (pH 6.5) at 30°C. Nickel content of the
sweat was determined after 1, 3 and 6 weeks using atomic absorption spectrometry.
Nickel release from the rivets ranged from