What Is SM-102? Moderna COVID Vaccine Ingredient Claim Debunked by Scientists

A conspiracy theory regarding the Moderna vaccine is being circulated on social media, in which anti-vaccination proponents raise concerns that the shot contains an ingredient that is unsafe for human use.

The conspiracy theory being spread by users on Twitter and TikTok highlights one Moderna vaccine ingredient; a lipid, or type of fat, known as SM-102.

According to Moderna, SM-102 is indeed listed among the ingredients of the vaccine.

Many of the social media posts and videos then highlight U.S. biochemical manufacturing company Cayman Chemical, which sells SM-102 as a research chemical.

The site states that the SM-102 product it sells is "for research use only, not for human or veterinary use."

It also includes a safety sheet that identifies hazards such as flammability and "harmful if swallowed," among others.

However, what the videos and posts do not show is that the SM-102 product sold by Cayman is a mixture of two substances—SM-102 and chloroform. It lists chloroform as the dangerous component, and not SM-102, which is listed as "other."

Substances are often prepared mixed-in with other chemicals that help them to dissolve. These substances that help with the dissolving process are known as solvents, and chloroform is used in this way. Even water can be used as a solvent.

Al Edwards, impact lead for the pharmacy research division at the University of Reading, told Newsweek: "Some solvents are often used to prepare things like lipids, but are removed after use.

"I don't know the exact process used to make the Moderna vaccine, but even if it did involve dissolving the lipid in a solvent such as chloroform, any residual amount of solvent left in the vaccine—if not fully removed—would be measured very precisely and listed as an ingredient. It would also only be allowed if it was known to be safe."

Chloroform is not listed as an ingredient in the Moderna vaccine.

Ed Hutchinson, a lecturer at the University of Glasgow's Centre for Virus Research, told Newsweek it is "entirely normal" for chemicals to be supplied in different grades of purity and that ones destined for human use would be treated with the greatest care.

"If you want an analogy—road grit and table salt are both salt, but you should only eat the more expensive and cleaner one," he said.

"Safety sheets for chemicals sold for purposes other than vaccines can look alarming for three reasons—they might refer to a less pure product than is used in vaccines; they might include warnings about additional compounds not present in vaccines—for example, flammable solvents; or they might refer to properties of the compound on its own that aren't present in the vaccine itself."

Edwards also said that fact safety sheets, such as the SM-102 one alluded to by anti-vaccination proponents, can easily be misinterpreted.

"A seller can label something as not for human consumption or use in medicines just because they don't want the product to be used in that way; the business does not want to certify that it's safe for human use."

"But this doesn't reflect that the product and all its components are unsafe—just that particular preparation.

"Peanuts sold for bird seed often are labelled in this way. That doesn't mean peanuts are hazardous to humans."

Newsweek has contacted Moderna for comment.

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A COVID vaccine being handled by a pharmacy technician in Aurora, Colorado, December 2020. The Moderna vaccine does not include chloroform as an ingredient, according to Moderna. Michael Ciaglo/Getty