Claim: Melting polythene in hot oil before frying sliced plantain in it will make plantain chips crispy.

There is no empirical evidence to back this claim which dates back to many years ago. Scientists suggest that the result would rather leave a layer around the chips which will make it unsafe for eating.
Full text
A social media user on Wednesday, January 14, 2021, claimed that she saw a plantain chips seller melting rubber in hot oil before frying the sliced plantain in it. According to her, the seller said doing so will make the chips crispy.
The post has gone viral and its text shared in various social media groups including on WhatsApp with a warning to persons who buy the product.
The claimant was not available to provide additional details but is it true that adding rubber to hot oil before frying sliced plantain in the oil will make the chips crispy?
Verification
Our checks reveal that this claim has been made several times already in the past and dates back to around 2014, as confirmed by a number of social media posts such as this, this and this.
In 2014 when the claim came up, there was again no evidence to back it.
“Apparently some plantain chips producers melt polythene into the cooking oil used in frying the chips to keep them crispy & ensure longevity,” a claimant said.
The Principal Regulatory Officer of the Food and Drugs Authority (FDA), Kofi Essel, in reaction to the claim on TV Africa in 2014 discounted it, arguing that scientifically it is not possible for the plastic material to completely dissolve in the oil to supposedly make plantain chips crispy. [40 secs. – 4 mins.]
“If you [try to] dissolve [rubber] in the oil, it stays in the oil as a gummy material…The plastic is only changing from one state to another physical state as a result of the heating conditions… If anything at all, you may be suspecting leaching,” he said in that interview.
Worldwide claim
A Google search on the subject shows that similar claims have been made on different online forums such as Tercharp and Rojakpot in the past.
In the article on Rojapot, several arguments were made to counter the claim, amongst them being the fact that it was suspicious that despite how widely that claim has circulated, there was not a single piece of evidence, either photo or video, to back it except for viral text messages on social media in which the persons who post it, usually claim they saw it themselves.
Also, the argument was made that any plantain chips that will be fried in such oil will be inedible because the gummy rubber will form a layer on the sliced plantain.
A video below was used to demonstrate what will happen when a plastic material is melted in hot oil.
To get further clarification on the subject, we contacted the co-founder of GhScientific, a science-based NGO focused on promoting Science, Technology, Engineering and Mathematics (STEM) education, Dr Thomas Tagoe. He said there is no certainty that melting rubber in hot oil before frying sliced plantain will make it crispy; however, a thin layer of rubber will most likely form on the chips which could make it firmer.
“Most polythenes that are used are said to be thermoplastic, meaning that when they melt they can be reformed and solidify upon cooling. So theoretically, it is possible that by melting the plastic in oil and frying with it, a thin layer of the plastic could form on the chips and this will give it a firmer, maybe stretchy texture,” Dr Tagoe, who is also a lecturer at the Physiology Department of the University of Ghana said.
On the possible risks associated with consuming any food fried in oil in which plastic has been melted it, Dr Tagoe said: “there is definitely a health risk.”
“Some plastics can leak chemicals which are dangerous within the body and have been linked to cancers and weakened immune systems. Then there are Microplastics, which are plastics too small to be seen with the naked eye (less than 5mm) have been linked to a number of health challenges that affect reproduction and childhood development,” he added.
A Ghanaian food researcher in France, Priscilla Ashie-Nikoi, also indicated that it is impossible for plantain chips to be made crispy by melting plastic in the oil used to fry it.
“Plastic cannot dissolve in oil, it can only melt, and it will stay in oil in the melted state, so it doesn’t contribute at all to the crispiness of plantain chips,” she said.
She adds that any food cooked in such oil would have an unpleasant smell; hence, it would be unlikely that anyone will eat such a product without one noticing.
She, however, suggested among other things that drying sliced plantain before frying it could make it crispy.
Conclusion
There is no definite science to back the claim that melting rubber in oil before frying plantain chips will make it crispy. Rather, evidence shows that the rubber will only change into a gummy state and will form a layer around the sliced plantain.