Material Safety - Stainless Steels
Safe use of Stainless Steel
Consideration of health and safety issues is important when customers are processing or using stainless steel, and when scrap items are returned for re-cycling.
As stainless steel is inert and non-reactive when employed correctly, potential health and safety impacts are extremely limited. This explains why stainless steel is so widely used in medical appliances and for equipment and tools in the food processing industry. In addition to long-term experience with stainless steel in a wide variety of applications, the material has also been tested and reviewed for possible health effects
The Company only stocks and sells stainless steel grades that are standardised and proven to be safe for their recommended use. To ensure that all products sold by the company comply with the specified requirements, only suppliers whose production sites are certified in accordance with the ISO 9001 quality standard are used. In addition, the company’s sales and distribution service centres are also certified in accordance with this quality standard.
Attached is a full material safety datasheet from a leading European manufacturer.
Scope - RoHS & WEEE
The Waste Electrical and Electronic Equipment directive, commonly referred to as WEEE. This is aimed at electrical and electronic equipment manufacturers and has two main aims:
1. Manufacturers will also have a responsibility for recycling products at the end of their life and there are targets manufacturers must meet.
2. To eliminate the use of environmentally sensitive substances from the manufacturing process of electrical and electronic equipment. To do this, the WEEE directive refers to the Restriction of Hazardous Substances (RoHS) directive.
The main objective of the R0HS directive is to eliminate the use of four metals and 2 flame retardants - For each of these substances a maximum concentration value of 0.1% by weight in electrical and electronic equipment is permissible:
- Hexavalent Chromium
- Polybrominated Diphenyls
- Polybrominated Diphenyl Ethers
In addition, there is an extra clause covering the exceptions which includes Lead, when used as an alloying element where the maximum concentration values are:
• 0.35% by weight in Steels (including Stainless Steel)
• 0.40% by weight in Aluminium
• 4.00% by weight in Copper alloys
Our suppliers have confirmed that we do not have a problem in supplying material that fully conforms to the RoHS directive and as a Company we can thus make the following statement:
We can confirm that the levels of:
Polybrominated Biphenyl (PBB)
Polybrominated Diphenyl Ether (PBDE)
are all below the maximum permissible levels stipulated in the European Directive 2002/95/EC (Restriction of Hazardous Substances), for all materials supplied by us.
The only exception to this is where a customer orders a grade of material where the British, European or International Standard covering that grade requires the level of one or more of the substances to be in excess of the RoHS Directive. In this case, the material will contain a value of each substance in line with the requirements of the standard.
Safety Information Sheet for Stainless Steel
Stainless steel products are considered as articles under the European Regulation (EC) 1907/2006, concerning the Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH), a position adopted by all European stainless steel producers as presented in the EUROFER (European Confederation of Iron and Steel Industries) position paper determining the borderline between preparation and articles for steel and steel products (1).
In accordance with REACH and the European Regulation (EC) 1272/2008 on Classification, Labelling, and Packaging of substances and mixtures (CLP), only substances and preparations require a Safety Data Sheet (SDS). While articles under REACH do not require a classic SDS, REACH Article 32 requires articles to be accompanied by sufficient information to permit safe use and disposal. In order to comply with this requirement, EUROFER members have developed a Safety Information Sheet (SIS) that provides information on the safe use of the stainless steel and its potential impacts on both human health and environment.
1. Article name and description
Outokumpu stainless steel products in massive product forms, non-coated or coated. Hot and cold rolled steel products like plate, sheet, strip, bar, rod, tube, fittings, wire rod. Stainless steel as defined in European Standard EN 10088:1:2014 covering corrosion resisting, heat resisting, and creep resisting steels
2. Article supplier
For regional contacts see our web page: www.outokumpu.com
3. Article composition:
Stainless steels are iron alloys that contain more than 10.5% chromium and less than 1.2% carbon. Composition below is given in weight percentages
Chromium: 10.5% to 30%
Nickel: max. 38%
Molybdenum: max. 11%
Carbon: max. 1.2%
Iron: balance (>50%)
Other elements such as Manganese (Mn), Nitrogen (N), Niobium (Nb), Titanium (Ti), Copper (Cu) and Silicon (Si) may be present. For more information on the chemical composition of standard stainless steels: see EN 10088-1:2014
Due to the natural origin of the material also some elements that have not been intentionally added may be present as impurities (Co, As, Sb). The concentration of these elements in some cases could accumulate up to more than 0.1%.
4. Article physical and chemical properties:
- Physical state: solid
- Colour: silver-grey
- Odour: odourless
- Density: 7.7 – 8.3 g/cm3
- Melting point: 1,325 to 1,530 ºC
- Water solubility: Insoluble
Stainless steels are stable and non-reactive under normal ambient atmospheric conditions, because in solid form all alloying elements are firmly bonded in the metallic matrix. Solid stainless steel does not contain Cr (VI) compounds. When heated to very high temperatures (melting or during welding operations), fumes may be produced.
In contact with strong acids, stainless steels may release gaseous acid decomposition products (e.g. hydrogen and oxides of nitrogen) and chromium may be released in the form of chromium III.
In contact with strong oxidizers at high pH (e.g. alkaline cleaners at pH 10-14), very small amounts of Cr (VI) compounds may form at ambient temperatures. None of these substances are intended to be released under normal or reasonably foreseeable conditions of use. Exposure to humans or the environment during normal or reasonably foreseeable conditions of use including disposal is negligible.
General Information on the safe use of Stainless Steel Products
Stainless steel is the term used to describe a versatile family of engineering materials, which are selected primarily for their corrosion and heat resistant properties. Corrosion resisting stainless steels contain a minimum of 10.5% chromium, which ensures the formation of a protective, adherent nanometric, oxide film covering the entire surface. Increasing the chromium content beyond the minimum of 10.5% confers still greater corrosion resistance. Corrosion resistance may be further improved, and a wide range of properties provided, by the addition of other chemical elements (e.g. nickel and molybdenum). Corrosion from stainless steel in aggressive media can be avoided by use of the proper grade in accordance with relevant European or international standards.
Stainless Steels are alloys. The alloying elements in stainless steel are firmly bonded in its chemical matrix. Due to this bonding and to the presence of a protective oxide film the release of any of the constituents is very low and negligible when the steel is used appropriately.
Stainless steels are generally considered non-hazardous to human health or the environment (see paragraph 4.1) and regularly applied where safety and hygiene is of utmost importance (e.g. equipment in contact with drinking water, food contact materials, medical devices, etc.).
This SIS presents relevant information for downstream users in order to secure a proper use of the stainless steel articles supplied.
1. Description of Hazards
1.1. Classification and Bio-elution
All intentionally added alloying elements in Stainless Steel with the exception of nickel are not classified as hazardous. Nickel is the only substance of major importance with regard to the hazard classification of stainless steels in the solid form. In accordance with (EC) Regulations 1272/2008 (CLP) and 790/2009 (ATP 1), nickel is classified as a Carcinogen Category 2, Specific Target Organ Toxicity Repeated Exposure 1 (STOT RE1) and Skin Sensitizer 1.
The exposure route for the nickel carcinogenic Category 2 classification is inhalation. However Stainless Steel in solid form cannot be inhaled, only when it is in powder form. The risk of being exposed to nickel in stainless steel can therefore also only exist when the stainless steel is in powder form. Nevertheless the European Classification is based on Hazard rather than on Risk. Therefore it is the obligation of the steel industry to provide proof that stainless steel is safe.
Even when steel is in powder form the likelihood of being exposed to nickel is far less than the pure metal thanks to the alloying effect. In other words when nickel is in the form of stainless it doesn’t necessarily become available to the organism which is inhaling the stainless powder. It is not bio available. This bio-availability can only be proven by doing in vivo testing using test animals. In vivo tests have been performed both on nickel powder and stainless steel powder (2, 3, 4).
As industry is encouraged to find alternative ways to animal testing the non-ferrous metals industry in Europe is developing a testing methodology based on Bio-elution. This methodology is an in vitro methodology thus preventing the necessity of in vivo testing. In Bio-elution body fluids like saliva, gastric, lung and intestinal fluids are mimicked and the specific release of constituents is tested. In these tests the bio-accessibility is being established.
The European Steel Industry together with the European Non-ferrous industry strongly believe that bio-accessibility in vitro tests will become a good and sustainable alternative to animal testing and we believe that bio-accessibility data are a good predictor of bioavailability and toxicity for use in hazard assessment.
According to REACH (5), alloys that contain Ni and that could come in frequent contact with skin, may be tested according to European standard EN1811 to determine the release rate of Ni. Tests conducted in accordance with this standard determined that stainless steels release nickel at levels significantly below the criteria set for classification as a skin sensitizer. Thus, stainless steels in general are suitable for use as piercing posts (where the maximum nickel release limits is 0.2 μg/cm2/week) and for applications involving close and prolonged contact with the skin (where the maximum nickel release limits is 0.5 μg/cm2/week).
However, tests conducted in accordance with EN 1811 (6) have shown that the resulphurised free machining stainless steels (containing 0.15 – 0.30 % sulphur) release nickel at levels close to, or above, the maximum nickel release limit 0.5 μg/cm2/week. Resulphurised free-machining stainless steels are, therefore, not suitable for use as piercing posts or for applications involving prolonged contact with the skin (i.e. jewellery, watch backs and watch straps, etc.).
Clinical studies did not reveal any risk of allergy among individual already sensitised to nickel. Thus, frequent intermittent contact with stainless steels of all types should not pose a problem to downstream users or consumers (7).
1.3. Specific Target Organ Toxicity
In accordance with the CLP Regulation, stainless steels are considered to be mixtures (8, 9). This means that stainless steels containing more than 10% nickel should be classified as Specific Target Organ Toxicity Repeated Exposure 1 (STOT RE1) and stainless steels containing 1 -10% nickel should be classified as STOT RE 2. Stainless steels containing less than 1% Ni are not classified.
However, a 28-day repeated inhalation study on rats with stainless steel in the powder form (2) clearly indicates a lack of toxicity (i.e. no adverse effects were seen, even at the highest concentration of stainless steel, which was 1.0 mg/L in the study), whereas the lowest nickel dose (0.004 mg/L) resulted in clear signs of toxicity in a 28-day nickel inhalation study (3, 4). No classification of stainless steel for STOT is proposed.
In accordance with the CLP Regulation, stainless steels are considered to be mixtures. This means that stainless steels containing more than 1% nickel should be classified as Carcinogen Category 2 when it is classified as a simple mixture. However, no carcinogenic effects resulting from exposure to stainless steels have been reported, either in epidemiological studies or in tests with animals (7). Therefore, it can be concluded that the weight of evidence supports the non-carcinogenicity of
In addition, IARC (International Agency for Research on Cancer) has concluded that stainless steel implants are not classifiable as to their carcinogenicity to humans (10). Several stainless steel grades are specifically designed for use in human implant parts (see ISO 5832).
Stainless steels containing less than 1% Ni are not classified
1.5. Summary classification
According to CLP an alloy can be classified either on its constituents classification (simple mixture) or on the hazard properties the mixture if they have been tested. Based on studies on the stainless steel alloy (7) the steel industry proposes the following classification for stainless steel:
No classification for most stainless steel grades
For re-sulphurised grades (0.15 – 0.30 % sulphur) Skin Sensitizer 1
For a comparison between classification according to constituent and classification based on alloy testing, see Annex 1.
2. Specific process and exposure controls
Dust and fume may be generated during processing e.g. in welding, cutting and grinding. If airborne concentrations of dust and fume are excessive, inhalation over long periods may affect workers’ health, primarily of the lungs. Dust and fume quantity and composition depend on specific practice. Oxidized forms of the various alloying elements of stainless steel may be found in welding fumes.
Over long periods, inhalation of excessive airborne levels may have long term health effects, primarily affecting the lungs. Studies of workers exposed to dust and fumes generated in the production of stainless steels have not indicated a respiratory cancer hazard (7).
Chromium in stainless steel is in the metallic state (zero valence) and stainless steel does not contain hexavalent chromium. Welding and flame cutting fumes may contain hexavalent chromium compounds. Studies have shown that some hexavalent chromium compounds can cause cancer. However, epidemiological studies amongst welders indicate no extra increased risk of cancer when welding stainless steels, compared with the slightly increased risk when welding steels that do not contain chromium. IARC has defined the welding process and welding fumes as a risk, irrespectively of which metals that are involved. (11).
The process of welding should only be performed by trained workers with the personal protective equipment in accordance with the laws of each Member State relating to safety. Guidance on the welding of metals and alloys is provided on the European Welding Association website (12). The guidance document will provide background information on health hazards posed by welding processes and appropriate risk management measures.
There are no specific occupational exposure limits for stainless steel. However, specific occupational exposure limits have been established for some constituent elements and compounds. Users of this Safety Information Sheet are strongly advised to refer to the occupational exposure limits set by their EU Member State for the substances in stainless steel and, where relevant, welding fumes.
3. First Aid Measures
There are no specific First Aid Measures developed for the stainless steel. Medical attention should be provided in case of an excessive inhalation of dust or a physical injury to the skin or to the eyes.
In case of eye injury note that austenitic stainless steel particles are non-magnetic or only slightly magnetic and may not respond to a magnet placed over the eye. In such cases seek hospital treatment.
4. Handling and Storage
There are no special measures for handling stainless steels. Normal precautions should be taken to avoid physical injuries produced mainly by sharp edges. Personal protective equipment must be used e.g. special gloves and eye protection.
Care should be taken to avoid exposing fine process dust (e.g. from grinding and blasting operations) to high temperatures as it may present a potential fire hazard.
Stainless steels are present in a wide variety of activities. Main use areas include industrial processes, architectural and building, house appliances and kitchenware, catering and transportation.
5.1. Food Contact
Stainless steel has been in use for contact with food for many years and is present in various articles (kitchenware, bowls, and industrial kitchen appliances). Depending on the application (knives, blades, forks, spoons, bowls), different grades are selected and have been recognized as safe. The Council of Europe has published new technical test guideline to ensure the suitability and safety of finished articles of metals and alloys in food contact (13). The release of specific constituents has to be below certain specific release limits (SRL). Some national laws also give detailed information on the choice of grades that should be allowed for food contact.
5.2. Medical devices and implants
In many cases stainless steel is the only material which can be used for medical devices and/or implants. Presently the Directive 90/385/EEC on Active Implantable Medical Devices and Directive 93/42/EEC on Medical Devices are being revised.
5.3. Drinking water
The 4MS Common Approach (agreed between Germany, France, the Netherlands and the United
Kingdom) describes a procedure by which a material is approved. The list of "Metallic materials suitable for drinking water under hygienic aspects" includes those metallic materials, for which the hygienic suitability for drinking water has been demonstrated. This includes stainless steel.
Safe use of stainless steel in toys is recognized in European Directive 2009/48/EC.
There are no hazards to the environment from stainless steel in the forms supplied.
Stainless steel is part of an integrated life cycle and it is a material that is 100% recyclable. Thus, surplus and scrap (waste) stainless steel is valuable and in demand for the production of prime new stainless steel. Recycling routes are well-established, and recycling is therefore the preferred disposal route. While disposal to landfill is not harmful to the environment, it is a waste of resources and therefore to be avoided for the benefit of recycling.
1. EUROFER position paper determining the borderline between preparations and articles for steel and steel products. 28 October 2008 http://www.eurofer.org/Issues%26Positions/REACH/REACH.itp
2. SafePharm Laboratories (2008). Stainless steel powder (Grade 316L): Twenty‐eight day repeated dose exposure inhalation (nose only) toxicity study in the rat, SafePharm Laboratories: 1 ‐249.
3. WIL Research Laboratories, I. (2002). A 4‐week range‐finding inhalation toxicity study of nickel metal in albino rats, WIL Research Laboratories, Inc.: 1‐319.
4. Inhalation carcinogenicity study with nickel metal powder in Wistar rats. A. R Oller et al., Toxicology and Applied Pharmacology 233 (2008) 262-275
5. Regulation (EC) No 1907/2006 of the European Parliament and of the Council of 18 December 2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH)
6. EN 1811:2011+A1:2015 Standard: Reference test method for release of nickel from all post assemblies which are inserted into pierced parts of the human body and articles intended to come into direct and prolonged contact with the skin (test for measuring Ni release in artificial sweat)
7. Review on toxicity of stainless steel, Finnish Institute of Occupational Health (FIOH), 2010 http://www.ttl.fi/en/publications/Electronic_publications/Pages/default.aspx
8. Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008 on classification, labelling and packaging of substances and mixtures
9. Regulation (EC) No 790/2009 1st Adaptation to Technical Progress (ATP) to the CLP Regulation
10. IARC (1999). Surgical implants and other foreign bodies. Geneva, World Health Organization, IARC.
11. Manufacture, processing and use of stainless steel: A review of the health effects, EUROFER, 1999 http://www.eurofer.org/index.php/eng/News Publications/Publications
12. http://www.european-welding.org/wp-content/uploads/2012/01/Communication statements_july_2010.pdf
13. Metals and Alloys used in food contact materials and articles, EDQM, CoE, 2013, 1st Edition, ISBN 978-92-871-7703-2, Specific chapter on Stainless Steels pp165, www.edqm.eu
Table 1 gives classification proposal based on testing performed on stainless steel, and Table 2 gives the classification according to constituents (in this case nickel)
Table 1. Classification proposal based on testing performed on stainless steel.
|Skin Sensitizing||Specific Target Organ Toxicity STOT||Carcinogenicity|
|Stainless steel||No Classification. For re-sulphurised grades only: Skin Sensitizer 1 H317||No Classification||No Classification*|
* As this proposal is based on weight of evidence on alloy testing it is not the CMR classification according to mixture rules in CLP. According to CLP, the carcinogenicity classification outlined in Table 2 should apply.
Table 2. Classification based on constituents
|Skin Sensitizing||Specific Target Organ Toxicity STOT||Carcinogenicity|
|Stainless steel <1% Ni||No Classification||No Classification||No Classification|
|Stainless steel <1% Ni||Skin Sensitizer 1 H317||STOT RE2 H373 (Inhalation)||Carcinogen Category 2 H351 (Inhalation)|
|Stainless steel >10% Ni||Skin Sensitizer 1 H317||STOT RE1 H373 (Inhalation)||Carcinogen Category 2 H351 (Inhalation)|