Creosote is an umbrella term for a range of chemicals that are used as wood preservatives. They are harmful to human health and the environment. There are reports that creosote on utility poles, such as telegraph poles, have caused skin burns.
The government’s Health and Safety Executive is reviewing the permitted uses of creosote and ran a consultation asking for views between September and November 2024.
This Insight explains when creosote is allowed to be used as a wood preservative in the UK, what uses are banned and how its use is regulated.
What is creosote?
Creosote is a biocide, which is “a chemical substance, mixture, or microorganism intended to control any harmful organism in a way that is not purely physical or mechanical”. It is highly effective as a wood preservative, protecting wood from insects, fungi, and decay.
Creosote is classified as a category 1B carcinogen under the GB Regulation on Classification Labelling and Packaging of Chemicals (CLP Regulation). This means that there is evidence that it has the potential to cause cancer in humans. It can also be toxic if swallowed or if it comes into contact with skin.
It can cause skin burns and eye damage and may cause allergic skin reactions, according to hazard information provided by manufacturers. However, the impact of creosote, as with all chemicals, depends on how and where it is used.
In the UK there have been media stories of people reporting skin burns after touching telegraph poles potentially treated with creosote.
The European Commission has also highlighted “significant environmental risks when wood treated with creosote comes into direct contact with soil or water”.
What uses of creosote are banned?
Consumer use of creosote was banned in the EU and UK in 2003.
Use of creosote and wood treated with creosote is restricted according to Annex XVII of the UK REACH Regulation, which regulates the manufacture and import of most chemicals in Great Britain. The restriction permits creosote for specified industrial uses, such as telegraph poles.
Wood that has already been legally treated with creosote for industrial uses cannot be used in parks, gardens, playgrounds or certain outdoor facilities where there is a higher risk of skin contact. It also cannot be used inside buildings or for garden furniture or toys.
Creosote-treated wood that was in use before the restrictions came into force is allowed to remain. There is no requirement to remove it.
What industrial uses of creosote are still allowed?
The UK REACH Regulation allows creosote to continue to be applied to wood for “industrial or professional use”, including on railway sleepers, telegraph poles, and certain types of fencing, as well as for agricultural purposes and in harbours and waterways. A guidance note on the use of creosote and creosote-treated wood (PDF, June 2023) from the Wood Protection Association, a trade body, has further examples.
The Health and Safety Executive (HSE), the regulator for health and safety in Great Britain, has noted that for these uses, essential timbers are in contact with the ground and “the service life of the treated wood is critical to safety”.
The UK REACH restriction does not ban industrial uses of creosote in all public places. So, for example, it is still possible for a telegraph pole to be treated with creosote and installed on a pavement.
How is the use of creosote regulated?
Biocidal products such as creosote are regulated under the Great Britain Biocidal Products Regulation (GB BPR). The EU BPR still applies in Northern Ireland.
There are two separate processes under the GB BPR: active substance approval, which is required for creosote, and product authorisations, which are required for specific products containing creosote. The HSE periodically reviews active substance approvals and product authorisations. If these expire and are not extended, the substances or products can no longer be used.
In response to a Freedom of Information request, HSE explained in March 2024 that because there is evidence of creosote having a carcinogenic effect in humans, it is considered a “candidate for substitution”. This means that “the approval of creosote is reviewed more often”, and only uses “for which there is no alternative” can be considered for approval.
HSE noted that, when the approval of creosote was last reviewed, “there was no suitably effective alternative to creosote” for uses such as railway sleepers and telegraph poles.
Could industrial uses of creosote be banned in future?
In May 2022, the Daily Mirror reported that creosote “will no longer be allowed to be used as of July 2023 under new laws”. This may have been referring to the upcoming expiry of the ‘active substance approval’ for creosote at the time, rather than a new law. In 2021, creosote’s active substance approval was extended to July 2023 to allow time for evaluation.
The active substance approval for creosote has been extended again, to February 2025, to allow time for HSE to evaluate whether to renew it. The EU BPR active substance approval for creosote in the EU and Northern Ireland has been extended to October 2029.
In a Freedom of Information request, HSE also said that there would be a public consultation to gather evidence on “whether not approving creosote would have a disproportionate negative effect on society compared with the risks to human and animal health and the environment from its use”. The consultation would also gather information about the availability of suitable alternatives to creosote.
This HSE consultation took place between September and November 2024. The HSE consultation noted the toxicity of creosote but explained that “it may still be possible to renew the approval of creosote” if it can be shown that:
- under normal use the risk is negligible;
- creosote is essential to prevent a serious danger to human or animal health or the environment; or
- not approving creosote would have a disproportionate negative impact on society compared to the risks of approving it.
About the author: Xameerah Malik is a researcher in the House of Commons Library specialising in chemicals regulation.
Photo by: Marcin Rogozinski via Adobe Stock