Is sodium benzoate in cosmetics carcinogenic?

What is sodium benzoate?

Sodium benzoate is sometimes used as a preservative in cosmetics. It is also used to extend the shelf life of carbonated drinks and processed foods.

Some people say that sodium benzoate is dangerous because it is carcinogenic . Others say that it has no particular effect on health. On what basis are these rumors being spread?

In this article, we will provide you with detailed information about sodium benzoate based on domestic and international research.

Benzoic acid is a naturally occurring ingredient

Sodium benzoate is a synthetic ingredient. However, its original benzoic acid is also a naturally occurring substance. It is also found in plants such as strawberries, cinnamon, and nutmeg . It also occurs naturally when yogurt and other foods are fermented. For this reason, it is sometimes listed as a " naturally derived ingredient " in cosmetics.

Carcinogens found in drinks containing vitamin C and sodium benzoate

Sodium benzoate has long been considered safe for most people.

Yet concerns about carcinogenicity are being raised. Why?

The trigger was the detection of a substance called benzene in soft drinks overseas.
It was pointed out that when sodium benzoate is mixed with a drink containing vitamin C, the two ingredients react to produce the toxic substance "benzene."

Benzene is a carcinogen

Benzene is a substance that the International Cancer Institute has determined to be "carcinogenic to humans," so it is not surprising that an increasing number of people are concerned about serious health damage.

In response to this incident, benzene concentrations in soft drinks were investigated in Japan as well , and benzene was detected, just as in other countries.

The US government asked major beverage manufacturers to improve their practices, but high levels of benzene were still found in carbonated drinks. As a result, lawsuits were filed against beverage manufacturers such as Coca-Cola and Pepsi in 2006.

Thus, concern about sodium benzoate spread throughout the world.

*The United States later set the maximum allowable intake of benzene in drinking water at 5 ppb. Meanwhile, Japan has no standard value for benzene in food (it only uses the WHO standard value of 10 ppb as a reference value).

Also linked to ADHD symptoms

A correlation between sodium benzoate intake and ADHD has also been pointed out.

A 2010 anonymous survey of 475 college students found that drinking large amounts of soft drinks high in sodium benzoate may be a contributing factor to symptoms related to ADHD.

Is sodium benzoate in cosmetics okay?

We now know that soft drinks containing vitamin C and sodium benzoate may pose a risk.
So what about cosmetics?

In Japan, the maximum amount of sodium benzoate in cosmetics is 1%. However, that is the only rule. There are no regulations prohibiting the use of these ingredients together with ascorbic acid. In addition, there is little information available on the safety of these ingredients being used together.

Is sodium benzoate good for the skin?

Some people experience skin irritation from cosmetic preservatives, and sodium benzoate is no exception, but the number of people who do this is not particularly high.

Patch tests conducted on 3,229 people between 2008 and 2022 reported that 1.8% of people had a positive reaction at a concentration of 5%.

The maximum concentration allowed in Japan is 1%. Considering this, it may be said that the percentage of people who experience allergic reactions to sodium benzoate is not high.

However, in reality, there is not enough data available about other aspects such as safety , and many details are still unknown.

Conclusion

Sodium benzoate is a natural preservative. For this reason, it is often used in organic cosmetics made overseas. If you have any concerns, such as the fact that it is used together with vitamin C, it may be a good idea to contact the manufacturer.