What is M-cresol?
M-cresol, also known as 3-methylphenol or meta-cresol, is an organic chemical compound with the CAS number 108-39-4. It is one of three cresol isomers (o-cresol, m-cresol, and p-cresol) that are aromatic hydrocarbons derived from coal tar or petroleum sources. M-cresol appears as a colorless to pale yellow liquid with a characteristic phenolic odor. The compound has a molecular weight of 108.14 g/mol and is slightly soluble in water but miscible with organic solvents.
Common Uses
M-cresol is classified as a flavoring agent or flavoring adjuvant in food applications. Its phenolic character gives it a sharp, medicinal taste profile that can be used in very small quantities to modify or enhance flavors in certain food products. However, practical applications of m-cresol in food are limited compared to other flavoring compounds. The substance has been more commonly used in industrial and pharmaceutical applications, including as a disinfectant, in the production of resins, and as a solvent in various manufacturing processes.
Safety Assessment
According to available FDA records, there have been zero reported adverse events associated with m-cresol as a food additive and zero product recalls linked to this substance. This absence of documented harm reports does not constitute definitive proof of safety, but rather indicates no identified safety signals in the U.S. food supply system.
M-cresol's toxicological profile has been characterized through various studies. The compound is considered moderately toxic when ingested in large quantities. Animal studies have demonstrated that m-cresol can cause irritation to mucous membranes and the gastrointestinal tract at high doses. Dermal and inhalation exposure studies have shown localized irritation effects. The phenolic structure of m-cresol, shared with other cresol isomers, underlies its irritant properties.
When used as a food additive in flavoring applications, the exposure levels are anticipated to be extremely low—typically measured in parts per million or lower. At these concentrations, the margin of safety would be considerably higher than levels shown to cause effects in toxicological studies.
Regulatory Status
M-cresol is not listed as a GRAS (Generally Recognized As Safe) substance by the FDA. This means it has not undergone the formal GRAS notification process or does not meet the criteria for GRAS status. The substance is not approved for use as a food additive in the United States under the Food Additives Amendment to the Federal Food, Drug, and Cosmetic Act.
In the European Union, m-cresol is not listed in the EU Register of flavouring substances authorized for use in food. This indicates regulatory restriction or exclusion from approved food additive lists in European jurisdictions as well.
The lack of FDA GRAS approval means that foods containing m-cresol as an intentional additive would be considered adulterated under U.S. law. Any occurrence of m-cresol in food products would need to be incidental and at levels that do not pose a safety concern, or would require specific FDA authorization.
Key Studies
Toxicological evaluations of cresol isomers, including m-cresol, have been conducted and documented in scientific literature. Studies on phenolic compounds have established oral LD50 values (lethal dose for 50% of test population) in laboratory animals, typically ranging from moderate to relatively low values depending on the isomer and species tested.
The chemical's irritant properties have been characterized through standard toxicological testing protocols. Given the structural similarity among cresol isomers, data on o-cresol and p-cresol provide relevant comparative information. However, specific human safety data for m-cresol in food applications remains limited, which is consistent with its restricted regulatory status.