Is milk from cows fed Bovaer safe?

Posts claiming that the methane-reducing cow feed additive Bovaer can cause cancer and is linked to Bill Gates have been circulating widely on social media, and we’ve been asked about them by readers. 

Examples include an amended screenshot of a real post on X from dairy company Arla Foods UK, which announced a new project with several supermarkets to trial the use of Bovaer on around 30 Arla farms. 

The X post claims that the additive can help reduce the emissions related to cattle farming. But in the versions being shared on social media, it has been overlaid with red text at the top saying “poison warning”, with extra text at the bottom which says: “A Bill Gates funded program is all you need to know. Avoid like the plague. Time to only shop locally.”

Another post we’ve seen circulating is an amended screenshot of a news release from Arla Foods about the project, with overlaid red text saying “Bill Gates poison” and “BOYCOTT ALL ARLA FOODS PRODUCTS” at the bottom.

But Bovaer has been approved by UK, EU and US food safety authorities, and is considered safe in the approved doses. Bill Gates was not involved in the development of Bovaer, and the manufacturer DSM-Firmenich says it fully owns Bovaer, which has no other investors.

Why are people worried about Bovaer’s safety?

Some social media posts have shared a screenshot of a report from the Food Standards Agency (FSA) and suggested it shows Bovaer was found to cause cancer. But this doesn’t tell the full story of what the FSA actually found.

The FSA reports that a carcinogenicity study of Bovaer, also known as 3-Nitrooxypropanol or “3-NOP”, “concluded there was evidence of carcinogenicity in female rats”. But a follow-up analysis found the rates of the disease in the rats fed the highest dose of Bovaer were not statistically significantly higher than the control group (who didn’t get the feed). 

Researchers concluded that at the highest dose, the additive had the potential to cause benign (non-cancerous) tumours and for that reason concluded that the level at which there was no observed adverse effect was 50mg per kilogram of body weight per day. But the FSA decided that the acceptable daily intake of 3-NOP should be even lower than this, at 0.3mg per kilogram of body weight. 

It said: “Due to the absence of malignant [cancerous] tumours and genotoxicity [the ability for a chemical to damage a cell’s genetic information], it was concluded that the additive is not carcinogenic at the recommended inclusion rate.”

It also concluded that Bovaer is “non-genotoxic in vivo [in a living organism].”

Professor Alastair Hay, Professor (Emeritus) of Environmental Toxicology at the University of Leeds, said via the Science Media Centre that “extensive tests” had shown that at approved doses the additive “presents no cancer risk”.

He added: “There is no evidence to suggest that at the doses approved for use in animals that the additive is a risk to humans through consumption of milk.”

An FSA spokesperson said: “Milk from cows given Bovaer, a feed additive used to reduce methane emissions, is safe to drink. Bovaer has undergone rigorous safety assessments and is approved for use in Great Britain.”

A blog by the FSA answers common questions about the additive and stresses Bovaer “does not cause cancer (it is not carcinogenic or genotoxic) and poses no safety concerns to consumers, animals or the environment”.

It adds: “More than 58 studies on potential risks were evaluated and it was concluded that the additive is safe at twice the recommended dose.”

Would milk from cows given Bovaer contain the chemical?

Professor Hay said: “Tests have been done on the milk of animals receiving 3-NOP and no metabolites were detected. The level of detection was 5 [millionths of a gram] per kg of milk. 

“Theoretical studies indicate that levels of 3-NOP possible in milk at the dosing levels proposed are some 100 times less than would occur at the dose accepted by the FSA as safe. The FSA states that a dose of 0.3mg (milligrams) per kilogram body weight is one it judges to be safe.”

Other posts circulating on social media include a screenshot of a letter from the US Food and Drug Administration (FDA) which says that “3-nitrooxypropanol may damage male fertility and reproductive organs, is potentially harmful when inhaled, and is a skin and eye irritant”.

But DSM-Firmenich told Full Fact this relates to human handling of the additive itself, not consumption of the milk produced by a cow that has been fed Bovaer. 

A spokesperson told Full Fact: “It has been tested over many years in many countries; it is totally safe and has been approved by regulators in Britain, America and many other countries.”

DSM-Firmenich said in a FAQ page on its website that a product safety sheet, as included in the letter from the FDA, “is a standard sheet which provides clear guidelines to people handling the product at processing facilities and ensures safe use”. It added: “Such procedures are quite common for feed supplements, such as vitamins, to ensure workers take appropriate measures (eg, wearing masks and gloves) to avoid risks from small dust particles.”

An Arla Foods spokesperson said: “Bovaer has already been extensively and safely used across Europe and at no point during the trial will there be any impact on the milk as it does not pass from the cow into the milk.”

The European Food Safety Authority said the use of Bovaer in the approved amounts “was of no concern for consumer safety and for the environment”.

The US Food and Drug Administration (FDA) likewise certified Bovaer as meeting safety and efficacy standards for use in lactating dairy cattle earlier in 2024.

What has Bill Gates got to do with Bovaer?

Mr Gates has invested in Rumin8—a company also working on its own dietary supplement which hopes to reduce the methane emissions of cow burps. But Rumin8 is not involved with Bovaer, Arla Foods or DSM-Firmenich. DSM-Firmenich says: “Contrary to what is stated in recent messages, Bovaer is fully developed and owned by DSM-Firmenich and has no other investors. Bill Gates is not involved in the development of Bovaer.”

An Arla Foods spokesperson described the online claims about a link between Mr Gates and Bovaer as “completely false” and the Bill & Melinda Gates Foundation likewise said “the claims linking Bill Gates to Bovaer are false”.

The Bill & Melinda Gates Foundation has previously given development grants to DSM-Firmenich, but these have been specifically for projects related to preventing malaria and improving water, sanitation and hygiene, and were not related to Bovaer. The foundation has also told Full Fact it doesn’t own equity or hold debt in DSM-Firmenich. 

Mr Gates has been the subject of widespread misinformation online, especially on the subject of public health due to his charitable work in the area. We have written about this many times. 

Misinformation like this can be harmful if people use it to make decisions about their health.