Propane-1,2-diol esters of fatty acids

About

What it is and where it shows up.

A mixture of propane-1,2-diol mono- and diesters of fatty acids derived from food fats and oils, appearing as clear liquids or waxy white flakes with a bland odour. Used as a food emulsifier and aerating agent in products such as cakes, whipped toppings, shortenings, and margarine.

Safety summary

The regulatory and scientific consensus.

EFSA re-evaluated E477 in 2018 and confirmed the previously established ADI of 25 mg/kg body weight per day expressed as propane-1,2-diol (equivalent to approximately 80 mg/kg bw/day for E477 itself); exposure estimates did not exceed this ADI in any population group. No genotoxicity concern was raised and no adverse effects were observed in short-term animal studies; however, the absence of chronic toxicity, carcinogenicity, and reproductive/developmental toxicity data for E477 itself is a recognised limitation. Any potential adverse effect is attributed to the propylene glycol (propane-1,2-diol) component released upon hydrolysis, not the intact ester.

Regulatory landscape

What food-safety regulators have decided.

Jurisdiction	Status	Note
EFSA (European Food Safety Authority) (European Union)	Approved	Approved under Regulation (EC) No 1333/2008 on food additives; specifications set in Commission Regulation (EU) No 231/2012. EFSA 2018 re-evaluation confirmed ADI of 25 mg/kg bw/day expressed as propane-1,2-diol, corresponding to 80 mg/kg bw/day for E477 itself (based on max 31% free and bound propane-1,2-diol per EU specification). Panel noted data gaps in chronic/carcinogenicity/reproductive toxicity and flagged potential need for a group ADI covering all propylene glycol-releasing additives (E477, E1520, E405).source
JECFA (JECFA (FAO/WHO))	Approved	ADI of 25 mg/kg bw/day (expressed as propylene glycol) first established at JECFA 17th meeting (1974) and reaffirmed at the 49th meeting (1997). Functional class: emulsifier. Listed in Codex GSFA (STAN 192-1995) as INS 477.source
FDA (Food and Drug Administration) (United States)	Approved	Regulated as a direct food additive under 21 CFR 172.856 (propylene glycol mono- and diesters of fats and fatty acids). Also listed as a permitted defoaming agent component under 21 CFR 173.340. No numerical ADI formally adopted in US regulations; use governed by GMP and defined technical effect (emulsifier, aerating agent).source

Who should approach with care

Whose guidance would steer them away.

Infants — Infants and very young children have a reduced capacity to metabolise propylene glycol (the primary hydrolysis product of E477), potentially leading to accumulation; EFSA noted the importance of assessing combined propylene glycol exposure across all relevant food additives in young age groups.

Kidney Disease — Propylene glycol and its metabolites (lactate, pyruvate) are renally cleared; impaired kidney function could increase systemic exposure from regular consumption of foods containing E477 and other propylene glycol-releasing additives.

Liver Disease — Propylene glycol is primarily metabolised hepatically; liver impairment may reduce clearance of the propylene glycol released upon hydrolysis of E477, increasing the risk of accumulation at dietary exposure levels.

Children — EFSA flagged the need for a group ADI covering all propylene glycol-releasing additives (E477, E1520, E405) and combined dietary exposure assessment, with children identified as a population group warranting closer monitoring due to higher relative food intake.

Research citations

The sources behind this verdict.

1WHO. JECFA database entry: Propane-1,2-diol esters of fatty acids (INS 477). apps.who.int
2FDA. 21 CFR 172.856 – Propylene glycol mono- and diesters of fats and fatty acids. accessdata.fda.gov
3EFSA. Re-evaluation of propane-1,2-diol esters of fatty acids (E 477) as a food additive, 2018. efsa.europa.eu
4PubMed. Re-evaluation of propane-1,2-diol esters of fatty acids (E 477) as a food additive, 2018. pubmed.ncbi.nlm.nih.gov
5PubMed (PMC full text). Re-evaluation of propane-1,2-diol esters of fatty acids (E 477) as a food additive, 2018. pmc.ncbi.nlm.nih.gov

Independently researched5 citations