Methylparaben

Methylparaben (CAS 99-76-3), also known as Tegosept M, is a synthetic antimicrobial preservative used in pharmaceutical, cosmetic, and food manufacturing.

Where is Methylparaben used?

• Pharmaceuticals: preserves oral suspensions, topical creams, and injectable preparations where microbial contamination control is a regulatory requirement
• Personal care: protects lotions, shampoos, and makeup products from spoilage throughout their shelf life
• Food and beverage: protects goods under FEMA 2710 designation
• Processed goods, beverages, and flavoring systems
• UV stabilizer in certain formulations, protecting active ingredients from photodegradation during storage and transport
• It inhibits the growth of bacteria, yeast, and mold in finished formulations.
• Normally used in a 3:1 combination with propyl 4-hydroxybenzoate.
• Suitable for preserving both rinse-off and leave-on formulations.
• Used in industrial settings such as adhesives, lubricants, and cutting fluids to prevent microbial growth.

Good to know: Extends product shelf life at low use concentrations. Standard grades include USP, BP, Ph. Eur., and FCC; technical grade is available where compendial certification is not required.

Formulation notes

• Typical use concentrations are 0.05-0.2% (average 0.075%).
• Easily soluble in lipophilic components; can be incorporated by adding it to the oil phase with some heating before any emulsification step.
• At pH values above 8, there is a risk of salt formation, which causes loss of preservative activity.
• In strongly acidic and strongly alkaline conditions, it can degrade by hydrolysis.

Typical specification

• Contains not less than 99.0% and not more than 100.5% of methyl 4-hydroxybenzoate according to Ph.Eur.
• Solubility in propylene glycol is 26% w/w.
• Remains completely stable over a wide pH range of 4 to 8.
• Solubility in vegetable oil (peanut) is 2.4% w/w.
• Very slightly soluble in water (1:500).

Regulatory status

• As a food additive, permitted in certain confectionery, processed meats, some table sweeteners and ready-to-eat snacks.
• Allowed as a preservative in cosmetics under Annex V (entry 12) of EU Regulation No 1223/2009, with a maximum concentration of 0.4% as acid for a single ester.
• In June 2025, France notified ECHA of its intention to propose a harmonized classification (CLH) as an endocrine disruptor for human health and the environment, which could lead to new restrictions in the future.

Storage, packaging and handling

• Should be stored in a well-closed container in a cool, dry place.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.