An unexpected chemical among us

In sustainable chemistry, even the experts can be surprised by what they missed or didn’t realize. It’s sometimes the case the chemicals that can be hazardous are formed by processes rather than added deliberately or knowingly.

As part of the Enhesa Toxicology team, I presented a poster about a very interesting chemical at the Society of Toxicology (SOT2024).  Surprisingly enough, 100% of the people who viewed the poster were unaware of their day-to-day interaction with the acetophenone azine chemical (CASRN 729-43-1). This chemical has been used as a biocide and an anti-parasitic for treating lymphatic filariasis, commonly known as elephantiasis, a painful and profoundly disfiguring disease. It is an illness that affects over 120 million people in 72 countries throughout the tropics and sub-tropics of Asia, Africa, the Western Pacific, and parts of the Caribbean and South America. The common question posed to me while presenting my poster (Acetophenone Azine: Molecular Weight Scaling for the Determination of Potential Chemical Hazards) was “is there an unexpected chemical among us?”

Toxic chemical in sports gear

There is an explanation for our day-to-day interaction with this chemical, but not regarding the health concerns mentioned above. Acetophenone azine may be found in sports equipment such as shin pads, sneakers foam, and flip-flop soles, mainly in copolymer ethyl-vinyl acetate (EVA) foam. It has been suggested that acetophenone azine is not intentionally added to the process of the foam manufacture but produced during the rubber vulcanization process with hydrazine hydrate (CAS RN 302-01-2) and dicumyl peroxide (CAS RN 80-43-3) becoming an unwelcome adulterant, or byproduct, or an impurity. It’s important to note that while acetophenone azine has various potential benefits, it is also essential to handle it with care as it can be toxic and harmful if not used properly. Moreover, this chemical was awarded the 2021 Allergen of the Year since it has been shown to be a skin sensitizer.

Chemicals for greener companies

It is admirable when companies strive to prioritize environmental sustainability and operate in an eco-friendly manner. Chemical safety is one of the pillars of becoming greener and sustainable. Enhesa provides chemical hazard assessments for companies that need accurate information to develop their safety foundation.

Our duty is to perform a chemical hazard assessment just as performed for acetophenone azine; the fact is that there is scarce information regarding the potential adverse effects on humans and the environment. We deployed various modeling tools and a mathematical model to predict acetophenone azine behavior in other unknown human and environmental settings. Besides the known characteristic of being a skin sensitizer, we could accurately determine the corresponding amount of exposure throughout its metabolites. Nevertheless, the hazard profile for this emerging chemical is still of high health concern.

We come in contact with numerous chemicals that remain unknown to us today and it is important that we are always gathering and sharing new information, which is why we saw a clear opportunity to spread new information in one of the most attended scientific toxicological forums. For the Enhesa Sustainable Chemistry team, communicating ideas and information about the possible impacts of chemicals on our health and environment is vital to empowering companies to produce compliant products.