Mixing different sun creams ‘might obliterate part of the protection offered from UV rays’

Mixing different sunscreens might nearly obliterate part of the protection offered from UV rays, a research suggests. 

Experts discovered combining ‘chemical’ creams with ‘mineral’ ones which comprise zinc oxide lowered the barrier they supply towards the sun by as much as 91 per cent.    

Researchers as we speak issued a warning to customers about the potential interplay, and mentioned the chemical can be present in SPF merchandise equivalent to moisturisers and make-up.  

Independent specialists as we speak emphasised the significance of creams and SPF-based objects for blocking the sun’s highly effective rays. 

Sunscreen is one of the greatest methods to each take pleasure in the sun and hold your self secure from a nasty burn and long run danger of pores and skin most cancers. 

Chemical sunscreens comprise substances which take up UV rays earlier than they attain the pores and skin, diffusing them in a chemical response.

These merchandise, also referred to as natural or artificial sunscreens, are absorbed by the physique.  

Whereas a mineral sunscreen, made of substances equivalent to zinc oxide or titanium dioxide, supplies a bodily barrier stopping UV rays from hitting the pores and skin.  

Mineral sunscreens have been marketed as a more sensible choice to these with delicate pores and skin, equivalent to youngsters, who can expertise irritation from chemical substances. 

Researchers have discovered mixing different varieties sun protection merchandise might dramatically cut back some of the protection offered 

Academics at the universities of Oregon and Leeds examined different SPF 15 sunscreen mixtures made of substances permitted to be used in the US and EU. 

Mineral vs chemical sunscreen. What’s the distinction?

Chemical sunscreens

These are additionally known as natural or artificial sunscreens and are the most typical sort of sunscreen.

They work by absorbing UV gentle and releasing it as warmth.

The following chemical substances might be discovered present in chemical sunscreens: Oxybenzone, Avobenzone, Octisalate, Octocrylene, Homosalate, Octinoxate

Chemical sunscreen is absorbed into the pores and skin and might generally trigger irritation.   

They should be utilized 20 minutes earlier than sun publicity and should be utilized often.

Example merchandise: Sun Bum, Nivea, Soltan

Mineral sunscreens 

Also referred to as bodily sunscreens, these work by absorbing after which scattering or deflecting the UV radiation along with absorbing the UV gentle and releasing as warmth.

Two substances are utilized in mineral sunscreens:  titanium dioxide, zinc dioxide.

Mineral sunscreens supply quick protection from the sun nonetheless might be washed off with sweat and water.

They are much less irritable to pores and skin however normally require bigger quantities to attain the similar protection as chemical sunscreens. 

Example manufacturers: Alba Botanica, Avène, Hawaiian Tropic

They examined the mixtures on their ranges of UVA protection, which is one ingredient of UV radiation, the different being UVB.

Though UVB is chargeable for most pores and skin cancers, each varieties of UV can doubtlessly trigger cancers. 

The researchers have been notably involved by one combination, the method of which represented the majority of sun cream mixtures utilized in the EU and US.

They discovered it suffered a 90 per cent drop in UVA protection when blended with 6 per cent zinc oxide after two hours publicity.

In comparability, when the method was uncovered to UV for 2 hours with out the zinc oxide it solely suffered a 16 per cent loss in protecting potential.

The scientists discovered that the zinc oxide, when uncovered to gentle, degraded the different UV absorbing chemical substances in the combination — lowering its protecting qualities. 

Co-author of the research Richard Blackburn mentioned folks ought to nonetheless use sunscreen however watch out about combining different merchandise. 

‘We nonetheless suggest customers use sunscreen however counsel they need to watch out to keep away from mixing sunscreen with zinc oxide, whether or not deliberately with hybrid sunscreens that mix small-molecule UV filters with zinc oxide, or by the way by mixing sunscreen with different merchandise containing zinc oxide, equivalent to make-up containing SPF,’ he mentioned. 

The research, printed in Photochemical & Photobiological Sciences, additionally discovered the mixed sunscreens had a better degree of toxicity after being uncovered to daylight in assessments on zebra fish embryos.   

Fish embryos uncovered to the sunscreen combination containing zinc oxide had larger adjustments of their regular growth such under-developed fins and shorter our bodies than different sunscreens.

However, when uncovered to solely zinc oxide the fish embryos didn’t have the similar response.

This indicated it was the mixture of the zinc and the different chemical substances driving the toxicity, the scientists mentioned. 

They admitted their findings are restricted as a result of they did not use the precise formulation utilized by sunscreen manufactures.

And the staff mentioned components, fragrances, and preservatives utilized in merchandise offered on the excessive road might react in another way.

Writing in the journal, they accepted extra work must be carried out on how different creams behave underneath different situations, and together. 

British Skin Foundation spokesperson and dermatologist Dr Emma Wedgeworth welcomed the research. 


Sunburn will increase an individual’s danger of pores and skin most cancers.

It can occur overseas or in the UK. 

To keep sun secure, specialists suggest folks:

  • Seek shade between 11am and 3pm, which is when the sun’s rays are sometimes strongest
  • Wear not less than SPF 30 sunscreen
  • Apply sunscreen half-hour, and once more simply earlier than, UV publicity
  • Opt for water resistant sunscreen if needed and reapply after swimming, sweating or utilizing a towel 
  • Cover up with protecting clothes, a wide-brimmed hat and sun shades
  • Be additional cautious with infants and younger youngsters. Infants underneath six months needs to be saved out of direct daylight
  • Do not use sunbeds or sunlamps 
  • Checks moles and pores and skin for any adjustments 

Source: NHS Choices 

However she added that Brits ought to understand that sunscreen had been proven to guard towards pores and skin most cancers and there was no proof it was poisonous to people.  

‘We are fortunate sufficient to have top quality requirements and rigorous testing of sunscreen merchandise out there in the UK and used, as per the directions, I’m assured that it affords very excessive protection towards damaging UV rays,’ she mentioned.

‘To date, there’s nonetheless no proof that sunscreen is poisonous to people and it’s troublesome to extrapolate research in zebra fish embryos to an actual life scenario of sunscreen utilization.’

Other scientists echoed Dr Wedgeworth’s feedback. 

Professor Winston Morgan, a toxicologist at the University of East London, mentioned whereas the research was of curiosity he was involved about the public’s knee jerk response. 

‘My concern is that the public may even see headlines from this research warning about sunscreen mixing and assume that each one sunscreens are usually not secure which might be mistaken and counterproductive,’ he mentioned. 

Professor Oliver Jones, an professional in chemistry from RMIT University In Melbourne Australia, additionally praised the research as ‘thought frightening’.

But he urged towards drawing an excessive amount of into influence on findings with the zebra fish embryos. 

‘While it is a well-used mannequin for ecological toxicity testing, zebrafish embryos are usually not mini people, and the outcomes are usually not straight comparable,’ he mentioned. 

‘I feel the danger of UV harm from not utilizing any sunscreen in any respect is increased than even the worst-case situation on this research. So briefly, don’t panic and hold utilizing sunscreen’.

Around 2,300 folks in the UK die from melanoma pores and skin most cancers which is primarily brought on by overexposure to UV rays, every year.

Of the close to 17,000 new instances of melanoma pores and skin most cancers reported in the UK every year, about 86 per cent are preventable in response to Cancer Research UK.       

Back to top button