Azo dyes are a large class of very effective synthetic dyes used for colouring a variety of consumer goods such as foods, cosmetics, carpets, clothes, leather and textiles.
A small proportion of azo dyes contain, or can break down to form, a class of chemical substances referred to as aromatic amines.
Certain aromatic amines such as benzidine, 3,3’-dimethoxybenzidine and p-aminoazobenzene that may be derived from azo colourants are considered to be hazardous. Expert authorities such as the World Health Organisation (WHO) International Agency for Research on Cancer (IARC) have classified some of these aromatic amines as known, or suspected, human carcinogens. A carcinogen is a substance that is capable of causing cancer. Exposure to a carcinogen does not mean cancer will result.
It is only certain azo dyes that are problematic – we understand the majority do not result in exposure to hazardous aromatic amines.
What are the hazards associated with certain azo dyes, including benzidine-based dyes?
Studies have shown that aromatic amines, like benzidine can migrate from clothing and leather articles dyed with azo dyes. Benzidine and other aromatic amines may be absorbed through the skin from dyed clothing and articles where there is direct and prolonged contact. The amount of aromatic amines released from dyed articles can increase with body heat, sweat or saliva. Many things such as; chemicals in some foods, diesel exhaust, alcohol and sunlight are classified as carcinogens and some amount of exposure is unavoidable and would not be expected to result in cancer.
The IARC classifies 3,3’-dimethoxybenzidine and p-aminoazobenzene as Group 2B carcinogens. Classification in Group 2B is the highest available to IARC when the carcinogenic effect is evident in animal studies but there is insufficient human data to assess the carcinogenicity to humans. It should not be taken to mean that the chemical is a less potent carcinogen than those classified in Group 2A or Group 1.
The European Scientific Committee on Toxicity, Ecotoxicity, and Environment (CSTEE) has affirmed the conclusion of a multinational assessment of the risk of cancer caused by textiles and leather goods coloured with certain azo dyes (including benzidine-based dyes), that while consumer exposure is likely to be very low, the associated cancer risks give cause for concern. As a result, exposure to certain azo dyes, including benzidine-based dyes, should be minimised or eliminated.
In 2013, the ACCC tested a range of articles for hazardous aromatic amines. Suppliers of dyed clothing and bedding found to contain hazardous aromatic amines above the acceptable limit of 30 mg/kg have acted responsibly to minimise possible risks to consumers associated with exposure and have voluntarily recalled the articles. The ACCC assisted these suppliers with their recall plans.
The ACCC resurveyed the market in 2015 to determine whether the state of the market had changed since the original survey was conducted and to inform the regulation impact statement which is in preparation.
The 2015 survey tested 102 clothing and textile articles for both adults and children, purchased from bricks-and-mortar and online retailers. The resurvey in 2015 found over 97% of products tested were compliant with the acceptable limit of 30 mg/kg for hazardous aromatic amines. Only 3 suppliers had products with detections above the acceptable limit and the ACCC worked with them to further investigate the survey result. Where adverse results were confirmed the suppliers removed the articles from the market through quarantining affected stock and voluntary recall action. See the Product Safety Recalls website for further information.
How do the 2015 results differ from the previous 2013 survey?
The results for the 2013 and 2015 surveys were similar with over 97% of articles tested passing. Of 199 articles tested in 2013, only four pairs of jeans and one pillowslip were found to contain hazardous aromatic amines over the acceptable limit of 30 mg/kg. In 2015, there were no detections of aromatic amines in 20 sets of pillowslips tested. The 2015 survey detected aromatic amines above the acceptable limit of 30 mg/kg in two brands of jeans and in one colour variant of socks.
Why did the ACCC conduct testing for hazardous aromatic amines in articles in 2013?
The National Industrial Chemicals Notification and Assessment Scheme (NICNAS) recently released a risk assessment of benzidine-based dyes in consumer goods which recommended that the ACCC consider approaches to managing the issue. The ACCC has regulatory responsibility for the safety of consumer goods supplied in Australia.
NICNAS recommended that the ACCC consider mechanisms to restrict the supply of textiles and leather articles which may come into direct and prolonged contact with the human skin where those articles may result in exposure to aromatic amines, released from benzidine-based dyes.
In considering the NICNAS recommendation, the ACCC conducted a market survey to determine if any dyes of concern had been used in the manufacture of consumer goods supplied in Australia.
The ACCC commissioned the testing of 199 clothing and textile articles that it purchased from mainstream suppliers in Australia. The samples purchased were dyed articles which may come into direct and prolonged contact with the skin. The purpose of testing was to measure the concentrations of 22 hazardous aromatic amines, including benzidine, that may be released from articles dyed with certain azo dyes.
The articles surveyed included mainstream adult and children’s articles purchased from major retailers both in store and online:
It is difficult to specify a ‘safe’ limit for the different hazardous aromatic amines that may be released from some azo dyes. Many common substances are classified as carcinogens and some exposure to them will not result in cancer. Experts do recommend minimising exposure to hazardous aromatic amines such as benzidine.
As consumers are not able to tell which articles contain certain chemicals and there are effective alternative dyes available to manufacturers, the ACCC takes the view that the maximum level for each hazardous aromatic amines in articles in direct and prolonged contact with the skin should be 30 mg/kg (which is 30 parts per million).
How widespread is this problem with hazardous dyes in clothing or bedding?
The evidence available to ACCC does not suggest the problematic azo dyes being used to dye certain articles is widespread. ACCC testing found over 97% of articles tested did not have high levels of problematic dyes. This result is consistent with testing conducted by other national consumer product regulators. Many Australian suppliers already have systems in place to manage for the possibility of the wrong dyes being used by manufacturers overseas however it is possible cheaper dyes are being substituted somewhere in the production process.
I’ve worn recalled clothing – what does this mean for me?
Exposure to hazardous aromatic amines from normal use of textile products that have been recalled would be very low - however expert authorities recommend minimising exposure - so you should stop using clothing or linen that has been recalled.
Does washing the clothing dyed with certain azo dyes reduce the concentration of hazardous aromatic amines?
Not necessarily. Some chemical residues will reduce significantly after washing, however the pre and post wash test results commissioned by the ACCC did not indicate a consistent decrease in the concentrations of hazardous aromatic amines after a single wash. In some cases the results after a single wash were slightly higher than the pre-wash test results.
What do I do if I’ve purchased a recalled article?
Stop using clothing or linen that has been recalled and contact the retail outlet you bought the product from and advise them that you have purchased a recalled product. Ask the retailer how you should return the recalled product and get a refund or other acceptable remedy.
You have the right to ask for a repair, replacement or refund under the Australian Consumer Law consumer guarantees for products and services bought on or after 1 January 2011.
Do other countries regulate azo dyes, including benzidine-based dyes?
A number of countries have specific regulations relating to certain azo dyes and hazardous aromatic amines.
In the European Union, 22 certain aromatic amines derived from certain azo dyes are restricted in articles which may come into direct and prolonged contact with the human skin or oral cavity. The maximum total concentration for all of the aromatic amines is 30 mg/kg or 30 parts per million.
The introduction of textiles or leather articles containing benzidine-based dyes is proposed to be restricted in the United States. Access to these dyes for home use is not permitted.
In a number of international jurisdictions benzidine based dyes are banned for use in cosmetics.
Where is the RIS up to? Is there going to be new regulation?
The ACCC has consulted on a draft Regulation Impact Statement examining the cost and benefits of options to limit consumer exposure to hazardous azo dyes through dyed clothing and textile articles. These options range from retaining the status quo to recommending to the Minister to introduce regulation under the Competition and Consumer Act 2010. All options must be subject to a cost benefit analysis in accordance with the Governments requirements. A final RIS which takes into account stakeholder submissions is expected to be submitted to the Office of Best Practice Regulation later in 2015. See Consultation for options to limit consumer exposure to hazardous azo dyes.
What are the potential types of risks to human health?
In Australia, the Hazardous Substances Information System (HSIS) provides that benzidine, 3,3’-dimethoxybenzidine and p-aminoazobenzene are classified as a Category 1 carcinogen, a known human carcinogen, and a Category 2 carcinogen respectively. According to the National Occupational Health and Safety Commission (NOHSC)’s ‘Approved Criteria for Classifying Hazardous Substances’ report, Category 2 carcinogens are substances that ‘should be regarded as if they are carcinogenic to man’.
NICNAS’ released risk assessment of benzidine-based dyes in consumer goods indicates that benzidine may pose a risk as a substance toxic to reproduction and development.