Forthcoming European PAH legislation
In December 2015, Europe will restrict the use of polycyclic aromatic hydrocarbons in rubbers and plastics.
by Martin Heels
Polycyclic aromatic hydrocarbons, (PAHs) are organic molecules that consist of two or more adjacent aromatic rings. Although they only contain the elements carbon and hydrogen, these atoms can exist in many different structural arrangements, so a large number of PAHs exist. They occur naturally in coal, crude oil and petrol, and can be formed during the incomplete burning of fossil fuels. Generally, the less efficient the burning, the more PAHs are formed. Studies have shown that there are possible short-term and long-term health effects from PAH exposure, and this has resulted in national and international legislation.
Existing legislation
In Germany, there are limits on the amounts of PAHs present in consumer products. Clause 30 of the LFGB (the food and feed code) restricts the amount of 16 PAHs that can be present in food contact items, such as packaging or plastic utensils. Clause 30 of the LFGB is also applicable to toys for children under 36 months of age that are intended to come into contact with the skin. Many PAHs – including seven of the eight restricted by (EU) 1272/2013 – are also listed in Californian Proposition 65, so warning labels must be attached if products on sale in the state of California contain these chemicals. There are current European restrictions in REACH 1906/2007/EC Annex XVII entry number 28, which bans the sale of PAHs to the general public in substances or mixtures, and entry number 50, although this only applies to tyres.
Effects on health
PAHs may pose a risk to human health by ingestion, skin absorption and inhalation. Studies with animals have shown exposure may cause eye irritation and vomiting. More seriously, they can increase the risk of skin, bladder, liver and stomach cancers. It is this increased long-term risk of causing cancers that is the most significant reason for the new European-wide legislation. From 27th December 2015, the eight PAHs listed in table 1 will be limited to a maximum concentration of 1mg/kg (1 part per million – ppm) in rubber or plastic components that come into contact with the skin or oral cavity. (EU) 1272/2013 includes the definition ‘direct, as well as prolonged or short-term repetitive contact with the human skin or the oral cavity, under normal or reasonably foreseeable conditions of use’. Footwear is specifically listed as an article included in the restriction.
Table 1: The eight PAHs restricted in (EU) 1272/2013 from 27th December 2015 | |
Polycyclic aromatic hydrocarbon (PAH) | CAS number |
Benzo[a]pyrene Benzo[e]pyrene Benzo[a]anthracene Chrysen Benzo[b]fluoranthene Benzo[j]fluoranthene Benzo[k]fluoranthene Dibenzo[a,h]anthracene |
50-32-8 192-97-2 56-55-3 218-01-9 205-99-2 205-82-3 207-08-9 53-70-3 |
PAHs in footwear
PAHs are not intentionally added to plastics or rubbers, but could be present as impurities. As previously mentioned, PAHs can be formed through the burning of fossil fuels. A commonly used pigment in black rubbers and plastics is carbon black, which can be manufactured by the partial combustion of oil or natural gas. Other combustion products can also be formed during this chemical reaction, and these include PAHs. Black rubbers and plastics are, therefore, more likely to contain PAHs than other colours. Extender oils (added to modify and cheapen processing or plasticiser oils) may also be manufactured from coal, crude oil or petrol that could contain PAH impurities.
How can we help?
SATRA is conducting a research project to increase understanding of which footwear materials are likely to contain polycyclic aromatic hydrocarbons and to evaluate methods of analysis. The information gained from this project will be discussed in future SATRA Bulletin articles. Please email chemistry@satra.com for further information on PAHs or chemical testing.
Publishing Data
This article was originally published on page 36 of the October 2014 issue of SATRA Bulletin.
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