Is sodium benzoate a safe replacement preservative for parabens?
Sodium benzoate and parabens are in the same class of chemicals, and in my opinion neither are safe preservatives. I’ll break it down to help you understand why it's not a safe preservative. Sodium benzoate is produced by combining benzoic acid with an alkaline substance like baking soda or soda ash. While baking soda and soda ash are safe, benzoic acid is a "compound comprising a benzene ring core" and is a known xenobiotic. Benzene is a proven carcinogen and a hormone disruptor at low doses. Parabens are esters of 4-hydroxybenzoic acid (also known as para-hydroxybenzoic acid). Parabens: 'para' + 'ben' (para = alongside, ben = benzoic acid). Methylparaben and ethylparaben in particular are linked to estrogenicity related diseases as is benzene. It is also noteworthy that sodium benzoate easily converts to benzene, a known carcinogen, simply by coming in contact with ascorbic acid (vitamin C).
Studies tell us that sodium benzoate negatively affects ovaries in mice, as well as decreases testosterone levels and thyroid hormones. A 2020 study found “that increasing doses of sodium benzoate significantly altered the weight of reproductive organs, decreased sperm count and motility and enhanced the percentage of abnormal sperms.” Additionally, clinical trials are underway to investigate the obesogenic endocrine disrupting chemical effects of benzoic acid because studies in piglets and chicks fed low levels of benzoic acid gained more weight than control animals.