The once-common classroom demonstration in which a condom dissolved in baby oil has largely vanished from UK sex education, according to teachers and experts. The experiment aimed to show students that oil-based lubricants break down latex, rendering condoms ineffective against pregnancy and STIs.
The disappearing classroom demonstration
Adults who attended UK schools in the 1990s and 2000s may recall the vivid lesson: a condom dropped into a container of baby oil would visibly disintegrate within minutes. The message was clear — never use oil-based lubricants with latex condoms. Yet today, many students have never seen this demonstration.
At a recent panel on sex education hosted by Queer Health, an initiative raising funds for LGBTQ+ health organisations, half of the panellists bonded over memories of the experiment while the other half had no idea what they were describing. Dr Henry Blest, co-founder of Polari Labs and a panellist, told Metro he had never encountered the practice until testing lubes in his laboratory, which specialises in anal douching.
Scientific basis: oil degrades latex in 25 minutes
Research dating back to a 1989 study confirms that oil-based lubricants degrade latex condoms. Dr Blest explained that in mechanical models, condoms exposed to oil-based lubes break down in about 25 minutes. 'What struck me was how invisible the risk is: the warning on the back of the bottle is tiny, and oil-based lubes are niche enough that most people would never think to look for it,' he said.
Sex and relationship expert Gigi Engle, author of Kink Curious and educator at sextoys.co.uk, told Metro that latex condoms and oil-based lubricants are 'completely incompatible.' She added: 'It can break down latex and cause condom breakage, making it ineffective.'
Why the experiment faded from classrooms
Lucy Emmerson, chief executive of The Sex Education Forum, explained that while relationships and sex education (RSE) has been mandatory in English schools for the past five years, there is wide variation in what is taught and how. 'Lessons on condoms and contraception are now standard,' she told Metro. 'Some teachers will include activities like opening and handling condoms and putting them on models, which is a useful skill for using them effectively. But including interactive activities like this is a matter of teacher choice, and also needs a long enough lesson.'
Emmerson noted that most teachers lack formal training in sex education, contributing to inconsistent lesson quality. 'It's high time this changed, and Sex Education Forum is calling for a clear plan for improvement including professionalising the teaching of this subject, which is so vital for young people's health and wellbeing,' she said.
Oil-based lubes: a growing trend with risks
Despite the incompatibility with condoms, oil-based lubricants have gained popularity for their longevity. Gigi Engle explained: 'You can put some on at the beginning of sex and it'll pretty much stay on because it's such an exclusive formula, particularly coconut oil. So many brands are using it, because it's all-natural, so it doesn't contain parabens.' However, she stressed that if condoms are the primary form of birth control, oil-based lubes are unsuitable.
Annabelle Knight, Lovehoney's sex and relationship expert, recommended water-based lubes as a safe alternative. 'They can also be used safely with silicone, which is what the majority of sex toys are made with,' she told Metro. 'If you want to use baby oil in the bedroom, then it can work as a massage oil, but generally there is no benefit of using oil-based lubes on genitalia that isn't covered by water-based or silicone options.'
Choosing the right lubricant
Experts advise selecting a lubricant based on the type of sexual activity. For anal play, a thicker, specially formulated gel is recommended because the anus cannot produce natural moisture. For solo play, some lubes may react poorly with certain sex toy materials, such as silicone or 'jelly style' finishes, causing surface degradation and potential bacterial harbouring. Knight emphasised that 'condoms are the most effective preventative measure against both pregnancy and STIs, so you don't want to risk breaking them.'
