Wits chemists hope to revolutionise the sunscreen industry with cashew nut shells.

Two Wits are part of a multinational team working on using cashew nut shells to potentially produce sunscreen.

For the past four years, Wits chemistry professor Charles de Koning has been in collaboration with Malawian chemist and Wits lecturer Dr Kennedy Ngwira, German colleagues Professor Till Opatz and Jonas Kühlborn and Tanzanian chemistry lecturer Dr Quintino Mgani to nurture their innovation.

“We use building blocks from discarded cashew nut shells in countries such as Tanzania [To make UVA and UVB absorbers],” De Koning said.

Ngwira said they extract a thick liquid called cashew nut shell liquid (CNSL), which contains  anacardic acid, cardol and cardanol, the team’s “building blocks”. In their research paper published recently in the European Journal of Organic Chemistry, the chemists said CNSL has “high technological potential… including anti-microbial, anti-inflammatory, anti-tumour, anti-oxidant and insecticidal properties”.

Ngwira explained that if someone is unprotected and exposed to UVA and UVB sunrays, they can develop conditions such as skin cancer from UVB rays or wrinkles from UVA rays.

“We have proved that our compounds are both UVA and UVB active, made from waste materials which are renewable resources,” De Koning said.

“A buzz term right now is ‘bio-driven economy’. The South African government is even promoting it now,” Ngwira said.

Ngwira said there is sustainability in their cashew nut innovation.

“We can always plant cashew nuts and regrow the trees,” he said.

Petrochemicals are chemical products derived from petroleum and can be taken from fossil fuels such as oil.

“We cannot rely on resources that are dwindling. Petrol prices have been constantly increasing, and extracting from petrochemicals is hazardous as it causes a lot more environmental waste,” Ngwira said.

De Koning said the environmental effects of sunscreen are topical.

Effective in 2021, Hawaii has banned the use of sunscreens containing chemicals such as oxybenzone that are harmful when absorbed by corals in the ocean.

A National Geographic article published in May explains that those dangerous substances not only bleach corals but also disrupt coral reproduction and growth cycles in oceans.

“[Would our product] be biodegradable? We don’t know; we still need to find out,” De Koning said.

However, the scientists foresee the prospects of their innovation.

“We saw there was the potential commercialisation of this, so Wits Enterprise decided that we should get a local provisional patent,” De Koning said.

The local patent has since been secured.

“Within a year we have to see if it is worthwhile to patent in other parts of the world,” De Koning said.

“The decision to patent in other countries largely depends on market analysis,” said Tumi Ngqondo, technology transfer manager at Wits Enterprise.

“This would include looking at where key market players and the target market are,” Ngqondo added.

FEATURED IMAGE: Wits chemists Professor Charles de Koning  (left) and Dr Kennedy Ngwira (right) have found a way to potentially make sunscreen from cashew nut shells. Photo: Ntombi Mkandhla