Formic Acid
AKA “Methanoic acid, Formylic acid, Aminic acid, Bilorin, Hydrogen carboxylic acid, Formisoton, Formira, Myrmicyl”
Acid
Ingredient Facts
Formic acid
AKA: Methanoic acid, Formylic acid, Aminic acid, Bilorin, Hydrogen carboxylic acid, Formisoton, Formira, Myrmicyl
Acid · Preservative · EWG: 4
Synthetic
Preservative
Acid
Clean
A gentle pH balancer that helps preserve the formula's freshness and effectiveness, keeping your product stable and safe to use.
Solubility greater than or equal to 100 mg/mL at 70 °F (NTP, 1992)
Formula
CH2O2
Mol. Weight
46.02
CAS #
64-18-6
Form
Liquid
State
Formic acid appears as a colorless liquid with a pungent odor. Flash point 156 °F. Density 10.2 lb / gal. Corrosive to metals and tissue.
See origin →
Functions
Ph Adjusters
Preservative
Keeps your product from growing bacteria, mold, or yeast. Without these, that jar of cream becomes a petri dish in about a week.
Moisturizing
Locks in moisture to keep skin soft and supple throughout the day
Prevents microbial growth
Provides scent
Adjusts product pH
Traditional Use
Historically obtained from ant venom and found in stinging nettles, formic acid was used in traditional European folk medicine for joint and skin conditions. Modern cosmetic use as a pH buffer and preservative dates to the 20th century.
Skin Types
●all-skin-types
Best For
General
Melanin-Rich Skin
Suitable
Pregnancy & Breastfeeding Safe
Caution
EWG
4
CIR
Safe w/Qualifications
Pregnancy
Caution
CIR Safety Findings
Not an Irritant
medical-approval
all-shades-safe
Concentration Guide
0.5%
0%1%
Reg. Limit
EU regulatory limit: 0.5%. Source: EU Cosmetics Regulation (EC) 1223/2009, Annex V (Preservatives), Entry 14.
Regulatory Agencies
Final Report on the Safety Assessment of Formic Acid
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Safety Assessment of Formic Acid and Sodium Formate as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Formic Acid
European Commission
EU Cosmetic Ingredient Database (CosIng)
Safety Assessment of Formic Acid and Sodium Formate as Used in Cosmetics.
Johnson W Jr, Heldreth B, Bergfeld WF, Belsito DV, Hill RA et al.
International journal of toxicology, 2016
Safety Assessment of Formic Acid and Sodium Formate as Used in Cosmetics.
Johnson W Jr, Heldreth B, Bergfeld WF, Belsito DV, Hill RA et al.
International journal of toxicology, 2016
Verified Feb 2026
Data: PubChem · CosIng · EWG · CIR