A number of top brand sunscreen products risk causing cancer if they’re left on a shelf for too long, a new study finds, revealing they release toxic chemicals over time.
Scientists from France and the US studied a number of randomly selected brand name sunscreen products containing the organic ‘sun filter’ chemical ‘octocrylene’.
Products from Garnier, Bioderma, LaRoche-Posay, L’Oreal, Coppertone, Banana Leaf and Neutrogena were purchased from shops in the US and France – including some aimed at babies and children.
Octocrylene is a common ingredient of sunscreens as it absorbs UVB radiation, which is responsible for sunburn and skin cancer, but is controversial as it is a potential allergen and isn’t biodegradable. It is already banned in a number of places.
The team from Sorbonne University found that octocrylene degrades into the carcinogenic chemical benzophenone when left on the shelf for more than a year.
Study authors say the manufacture of products containing the chemical octocrylene should be banned until the industry can prove ‘beyond doubt’ that it is safe.
Dr Emma Meredith, Director General of the Cosmetic, Toiletry and Perfumery Association (CTPA) said: ‘Octocrylene has been used in sunscreens for many years and no health risk from tiny quantities of benzophenone impurities has been shown.’
A number of top brand sunscreen products risk causing cancer if they’re left on a shelf for too long, study finds, revealing they release toxic chemicals over time
The CTPA says the report may appear alarming but doesn’t need to cause concern as the results and health concerns are not directly transferable to humans.
Dr Meredith said: ‘This study does not change the fact that sunscreens and their ingredients are safe, effective and an essential part of a sunsafe regime for protecting our health, as advised by dermatologists globally.’
‘We can be reassured that the safety of every single sunscreen must be approved by a highly qualified specialist before it can be sold in the UK.’
The issue isn’t so much in the product itself, rather how long it is being used, or left unused between summer holidays.
Families will purchase a sunscreen, use it for two weeks over the summer and then put it in a cupboard to use again the following year – but, study authors say this could be very dangerous.
Researchers, including a team from the Haereticus Environmental Laboratory in the US, didn’t claim octocrylene in itself was cancer causing, rather the chemicals produced when it breaks down over time.
Among them is benzophenone, which is a ‘mutagen, carcinogen and endocrine disruptor’ which can lead to cancer.
An endocrine disruptor is a chemical that can interfere with the messengers in the body that regulate the circulatory system and can result in cancerous tumours.
The one product the team tested which did not contain octocrylene was Nivea Sun SPF 50+, which they used as a control subject.
They found that after ageing all of the products this is the only one that didn’t contain any benzophenone, allowing them to confirm it was octocrylene causing the build up of the carcinogen.
Dermatologist, Dr Sharyn Laughlin, involved in this study, said she was gravely concerned regarding the far-reaching consequences of this new research.
‘Benzophenone is still the worst offender in causing contact dermatitis, and may induce uticaria and anaphylaxis. Absorption of both chemicals through the skin poses a potential threat to toxicities and diseases of other organs.’
Benzophenone is already banned in food products and food packaging in the US and from personal care products including sunscreens and moisturisers.
Scientists from France and the US studied a number of randomly selected brand new sunscreen products containing the organic ‘sun filter’ chemical ‘octocrylene’
Finding out that concentrations of the harmful chemical increase in sunscreen containing octocrylene the older it gets is ‘very worrying,’ the team said.
To test their theory that benzophenone is produced over time from octocrylene, the team selected a random number of creams directly from stores after looking for the best sellers.
They then artificially aged them over a six-week period to replicate conditions found in a normal family home over the course of an entire year.
Benzophenone developed in increasingly high concentrations the older the product got – so buying sunscreen to use on holiday and then leaving it for a year before using it again could be harmful.
Both octocrylene and benzophenone are readily absorbed into the skin.
Dermal absorption of benzophenone into the body may exceed 70%, based on topical studies conducted by Howard Maibach and colleagues in the 1990s.
The French team say this is a strong argument for regulatory prohibition of this chemical in perfumes and other topical products.
The CTPA says manufacturers carry out their own studies to show that sunscreens change over time to ensure they are safe and effective during their projected lifetime.
Sunscreens don’t have expiry dates in the UK but does have a limited shelf life of less than 30 months and is labelled with a best before date, the CTPA explained in a statement on the study.
‘The vast majority of sunscreens safely last longer than 30 months, and these may be labelled with a ‘period after opening’ (PAO) open jar symbol,’ a spokesperson said.
‘The PAO is not an expiry date, but shows that once opened the product will not deteriorate to cause harm to the user.’
In 2019, almost 3,000 commercial products sold in the United States contained octocrylene, including shampoos, hair conditioners, and hair sprays.
The latest research revealed that L’Oreal Age Perfect FPS 20 had the highest concentration of benzophenone after ageing – up 200 per cent on the rate found before the ageing process began – or 214mg per kg.
Products from Garnier, Bioderma, LaRoche-Posay, L’Oreal, Coppertone, Banana Leaf and Neutrogena were purchased from shops in the US and France – including some products aimed at babies and children
In the US the highest increase was found in Coppertone Sport Clear SPF 30 which went up 134 per cent to 408mg per kg – the highest of all products tested.
In mammalian-model studies, benzophenone exposure quickly gave rise to liver cancers and lymphomas, the team behind the new research explained.
Benzophenone can act as a photo-mutagen; in the presence of light, it increases the rate of DNA lesions, thus increasing the risk of skin cancers.
Benzophenone is also an endocrine disruptor, affecting thyroid function as well as inducing anti-androgenic activity, delaying testicular development and causing anatomic difficulties with female reproductive organs.
The team from Sorbonne University found that octocrylene degrades into the carcinogenic chemical benzophenone when left on the shelf for more than a year
Octocrylene can be removed from personal care product formulations, the US team said in a statement about the new study.
‘It is a challenge to formulate aesthetically pleasing and effective sunscreens without using endocrine disrupting chemicals, but it can be done,’ said Autumn Blum, CEO of Stream2Sea, a biodegradable sunscreen manufacturer not involved in the study.
‘It is possible major manufacturers and ingredient suppliers can pay attention to the science that clearly shows the danger, and industry needs to invest in the innovation necessary to develop products that are safe for consumers and ecosystems.’
Dr Craig Downs, sunscreen expert not involved in the study told The Telegraph that previous research into the chemical was from industry insider papers.
‘This paper blows all of that up and calls into question all of the industry narratives that octocrylene is safe to be used,’ he said.
Study authors say the manufacture of products containing the chemical octocrylene should be banned until the industry can prove ‘beyond doubt’ that it is safe
Adding that he now hopes the industry will invest in hunting for a safer and more environmentally friendly alternative to octocrylene.
The researchers say that responsible regulation to prohibit the development and sale of the chemicals should be considered until industry can prove they are safe.
The findings of this study provide new scientific evidence to argue that octocrylene-based products – and therefore contaminated with benzophenone – can pose a threat to individual and public health, as well as the environment, the team warned.
‘Our results plead in favour of the implementation of regulations dictated by the precautionary principle, the objective of which would be the protection of public health and the environment.’
All the firms named in the study have been approached for a comment.
Industry body CTPA said the new study doesn’t show that sunscreens containing octocrylene pose any health risk to humans, just that benzophenone impurities can exist after manufacture in sunscreen products.
‘The strict UK and EU cosmetics laws acknowledge that traces of impurities may be present or develop in products over time, but the rules are very clear that any presence must not cause harm to human health,’ a spokesperson said.
Octocrylene is approved for use as a sun protector in the US, EU and the UK but can pose a risk to marine life and lead to bleaching of coral reefs.
It is also not biodegradable, leading it to be banned in a number of places including the Marshall and US Virgin Islands.
L’Oreal, which produces a number of products tested by the team, said: ‘The use and concentration of octocrylene in our sunscreen products is carefully controlled to avoid any potential impact on the aquatic environment.’
The findings have been published in the journal Chemical Research in Toxicology.