Chemical innocuousness testing of PPE
Investigating the requirement that a personal protective product must not expose the wearer to any additional hazards during normal use.
The wearing of personal protective equipment (PPE) is a very important aspect in any safe working environment. While PPE may be worn as part of the employer’s duty of care in the workplace, there are many different types used commercially and domestically – from safety glasses to protective gloves. Using the correct PPE for the task at hand can help to protect the wearer from avoidable injuries – both minor and serious – but the protective equipment itself must also be assessed to ensure it will not harm the user.
PPE which is intended for the European market must comply with the requirements of the European PPE Regulation (EU) 2016/425, which replaced the European PPE Directive 89/686/EEC on 21st April, 2018. Annex II of the regulation gives a summary of the basic health and safety requirements with which products must comply. Clause 1.2 of Annex II is a requirement for ‘innocuousness’. This means that the PPE product itself must not expose the wearer to any additional hazards during normal, foreseeable use. REACH (Regulation (EC) No 1907/2006) Annex XVII restricted substances legislation is applicable to all products, including PPE, and additional testing may be required in order for the item to comply with REACH requirements.
This article details the chemical innocuousness requirements for protective clothing, footwear and gloves under the PPE Regulation. It will give a broad overview of the chemical testing carried out at SATRA that helps manufacturers to demonstrate that their products are safe and comply with the PPE Regulation. This test data is essential if EU-type examination is required. There are various types of products covered in the PPE Regulation, and the safety requirements and performance characteristics are mainly laid down in European and international standards. These can include substances that have been restricted or banned due to their known harmful effects.
Even if a product standard for a PPE type does not contain specific requirements for named substances, the innocuousness clause requires that an assessment is made based on the materials used and the product construction and intended use. For example, EN 420:2003+A1:2009 – ‘Protective gloves. General requirements and test methods’ only lists pH, Chromium VI and extractable latex protein testing. However, more tests may be required once an assessment of the materials has been made. This standard will soon be replaced by EN ISO 21420, which is expected to be published in the near future. Changes to the innocuousness clause include the removal of extractable latex protein testing and the addition of testing for nickel, azo colourants and dimethylformamide (DMFa).
The innocuousness requirements in these standards are not exhaustive lists of possible hazards in PPE products. Therefore, Notified Bodies such as SATRA may have to conduct chemical innocuousness testing that is not specifically mentioned in the standard in order to provide EU type-examination certification. Clearly, products can vary greatly in manufacturing processes and material composition, and SATRA can advise any additional chemical testing in order to ensure full compliance with the PPE Regulation and REACH Annex XVII. In order to determine what chemical testing is required, SATRA will assess the finished product and recommend a testing regime which will, if the performance requirements are satisfied, enable the customer to state with confidence that the product complies with relevant European legislation.
The following is a summary of some of the main chemical innocuousness testing carried out at SATRA. Our knowledgeable staff can advise on relevant testing for specific items of PPE.
The ‘pH’ value of a material is an indication of how acidic or alkaline it is, and this is measured using the pH scale from 0 to 14. A measurement of below 1 is strongly acidic and 14 is strongly alkaline. Skin irritations can occur if a material in a PPE product has a very high or very low pH value, and particularly if the acids or alkalis present are ‘strong’ – that is, if they are highly ionised. In safety footwear, gloves and protective clothing, the pH value of leather must be above 3.2. A high or low pH value could also affect the integrity of the product, and therefore cause a safety issue. In addition – for protective footwear – if the pH value is below 4, the difference in pH between a test specimen that has been diluted to one-tenth of its original strength and the original specimen must be less than 0.70. Protective clothing and gloves, textiles and other materials must have a pH value of between 3.5 and 9.5, thus excluding the extremes of acidity and alkalinity. These pH requirements are also set in place to not only prevent harm to the user, but also to ensure quality components and product integrity.
Chromium is a ‘transition metal’, the salts of which are used in leather tanning. In leather, it can exist in two main states, known as ‘chromium III’ and ‘chromium VI’. In finished leather, it is usually only present as chromium III. It is possible, however, that during the tanning process or under certain storage conditions, some chromium III can be oxidised to chromium VI, which is a known skin irritant, potential carcinogen and environmental hazard. Chromium VI is currently restricted under REACH – Regulation (EC) No 1907/2006 Annex XVII entry 47, and requires that there is less than 3mg/kg of chromium VI present. The detection limit in ISO 17075-2:2017 (the reference test method to quantify the amount of chromium VI in leathers) is 3mg/kg. Hence, a result of none detected will be reported as ‘<3mg/kg’.
Extractable protein content of latex products
Natural latex proteins are known to cause allergic reactions in many people. One common product in which latex is used is the single-use medical examination glove. The nature of this product causes the wearer and the patient to have direct skin contact with the latex. This means that the issue of allergies must be considered as part of the chemical innocuousness testing. Latex protein testing is currently required under EN 420:2003+A1:2009, although in the upcoming EN ISO 21420 standard, this test requirement will be removed. SATRA can offer testing to determine the level of natural latex proteins. The test data is required to be marked on the product or the packaging, in order to allow the end-user to make an informed choice of suitable product.
Some of the dyes within the azo family (compounds containing the functional group -N=N-) can break down to form aromatic amines, which are carcinogenic. There are currently 22 restricted aromatic amines within REACH Annex XVII entry 43. Dyed textiles or leathers which are in direct or prolonged contact with the skin should be tested for the presence of these aromatic amines. The ‘azo dyes restriction’ is a specific condition within EN ISO 13688:2013 – ‘Protective clothing. General requirements’. For other products, however, SATRA recommends testing dyed textiles and leather which have the potential for skin contact. This is to ensure that the products meet the innocuousness requirements of the PPE Regulation. In addition, it will be added to the upcoming EN ISO 21420 standard, which will replace EN 420:2003+A1:2009.
Metal components (such as buckles and eyelets) can sometimes cause skin allergies if they are in direct or prolonged contact with the skin. This is usually due to the presence of nickel. According to EN ISO 13688:2013, all metallic materials which could come into prolonged contact with the skin must have an emission of nickel of less than 0.5µg/cm2 per week. This restriction is part of clause 4.2 of EN ISO 13688:2013, and is also covered by REACH Annex XVII entry 27. In addition, it will be added to the soon-to-be-published EN ISO 21420 standard.
Dimethylformamide (N,N-dimethylformamide – ‘DMFa’) is a solvent used when coating or dipping protective gloves with polyurethane (PU). DMFa can be rapidly absorbed through the skin and is known to cause harm to the liver, as well as abdominal pain, constipation, nausea and vomiting, headache, weakness, dizziness and skin problems. Furthermore, it was recently classified as a ‘Group 2A substance’ by the International Agency for Research on Cancer (IARC), which defines it as being ‘probably carcinogenic to humans.’ DMFa is restricted by the German TRGS 401 Technical Rules for Hazardous Substances and is also listed in REACH as a Substance of Very High Concern (SVHC). Once EN ISO 21420 is published, it will also be a required test for innocuousness by the EN 16778:2016 test method for all gloves containing PU.
Polycyclic aromatic hydrocarbons (PAHs) are organic molecules that consist of two or more adjacent aromatic rings. They occur naturally in coal, crude oil and petrol, and can be found in plastic or rubber materials as impurities. Studies have shown there are possible short-term and long-term health effects from PAH exposure. This has resulted in national and international legislation, including REACH Annex XVII entry 50 as amended by European Regulation (EU) 1272/2013. PAHs may pose a risk to human health by ingestion, skin absorption and inhalation, and may cause eye irritation and vomiting.
There may also be long-term effects, such as an increased risk of cancers in the stomach, skin, bladder and liver. While REACH Annex XVII only lists eight PAHs, SATRA’s internal testing procedure can identify and quantify up to 24 PAHs by Gas Chromatography with Mass Spectrometry (GC-MS). Results for the additional PAHs can be helpful if testing to more stringent standards such as the German GS Mark, which has a restriction on the sum of 18 individual PAHs.
Pentachlorophenol (PCP) has historically been used as a fungicide for natural materials such as cotton, leather and wool. Its use is restricted, as it is known to be highly toxic to humans and has been linked to some forms of cancer. REACH Annex XVII entry 22 states that PCP must not be detected in materials in concentrations above 1,000 parts per million (ppm). In Germany, there is also a requirement that PCP shall not be detected in concentrations above 5 parts per million (ppm). Natural materials, such as cotton or leather used in gloves or clothing, either require testing for PCP or valid test reports to confirm its absence.
Chemical innocuousness testing is an important part of assessing the safety of PPE for the European market. Evidence of the absence of restricted substances listed in REACH and product specification standards is required in order for Notified Bodies to certify PPE, and therefore for the product to be labelled with the CE mark.
SATRA can provide a comprehensive service to guide the customer through the legislative requirements. Finished products can be assessed by our experienced staff to determine which substances are relevant, so that only the correct materials are assessed for the appropriate restricted substances. This ‘targeted testing’ approach helps to minimise the costs of chemical innocuousness testing which, if satisfactory results are obtained, will enable the customer to place the product in the marketplace with confidence.
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