2-Phenoxyethanol

Toxicity

LC50 oral, rat; 1980 mg/kg . LD50 Rabbit dermal 2250 mg/kg.
2-Phenoxyethanol (PhE) has been shown to induce hepatotoxicity, renal toxicity, and hemolysis at dosages ≥ 400 mg/kg/day in subchronic and chronic studies in multiple species.
The major hazards encountered in the use and handling of 2-phenoxyethanol stem from its toxicologic properties. Toxic by all routes (inhalation, ingestion, and dermal contact), exposure to this very faintly aromatic, colorless, oily liquid may occur from its use.

Description

2-Phenoxyethanol, known early on as ethylene glycol monophenyl ether, is a high-boiling, oily liquid that is moderately water-soluble. It has a long history and several uses in chemical manufacturing and consumer products.

Description

Phenoxyethanol is an organic chemical compound, a glycol ether often used in dermatological products such as skin creams and sunscreen. It is a colorless oily liquid. It is a bactericide (usually used in conjunction with quaternary ammonium compounds). Phenoxyethanol is used in many applications such as cosmetics, vaccines and pharmaceuticals as a preservative.

Chemical properties

clear colorless liquid

Chemical properties

Phenoxyethanol is a colorless, slightly viscous liquid with a faint pleasant odor and burning taste.

Characteristics

Phenoxyethanol is a tried-and-tested preservative, which is welltolerated by the skin and has a low allergy risk. It can be used over a wide pH range. This means that other preservatives can lose their effectiveness if the product is not within the right pH range. It does not smell unpleasant or change the color of the product, which can be the case when using natural antimicrobial substances.

The Uses of 2-Phenoxyethanol

Phenoxyethanol is a preservative used in consumer and health care products, including vaccines, pen inks, ear drops, shampoos, skin cleansers, moisturizers, sun care products, and topical medicaments. The preservative Euxyl-K 400 also contains 2-phenoxyethanol, in combination with methyldibromoglutaronitrile.

The Uses of 2-Phenoxyethanol

Antimicrobial preservative; also used topically in treatment of bacterial infections.

The Uses of 2-Phenoxyethanol

phenoxyethanol is a broad-range preservative with fungicidal, bactericidal, insecticidal, and germicidal properties. It has a relatively low sensitizing factor in leave-on cosmetics. Phenoxyethanol can be used in concentrations of 0.5 to 2.0 percent, and in combination with other preservatives such as sorbic acid or parabens. In addition, it is used as a solvent for aftershaves, face and hair lotions, shampoos, and skin creams of all types. It can be obtained from phenol.

The Uses of 2-Phenoxyethanol

Ethylene glycol phenyl ether at a 1.0% level acts as a preservative in personal care products.

Background

Phenoxyethanol is a colorless liquid with a pleasant odor. It is a glycol ether used as a perfume fixative, insect repellent, antiseptic, solvent, preservative, and also as an anesthetic in fish aquaculture. Phenoxyethanol is an ether alcohol with aromatic properties. It is both naturally found and manufactured synthetically. Demonstrating antimicrobial ability, phenoxyethanol acts as an effective preservative in pharmaceuticals, cosmetics and lubricants.

Production Methods

Phenoxyethanol is prepared by treating phenol with ethylene oxide in an alkaline medium.

Definition

ChEBI: 2-phenoxyethanol is an aromatic ether that is phenol substituted on oxygen by a 2-hydroxyethyl group. It has a role as an antiinfective agent and a central nervous system depressant. It is a primary alcohol, a glycol ether and an aromatic ether. It is functionally related to a phenol.

Synthesis Reference(s)

The Journal of Organic Chemistry, 40, p. 1356, 1975 DOI: 10.1021/jo00897a043

General Description

Colorless liquid with a pleasant odor. Density 1.02 g / cm3. An irritant.

Air & Water Reactions

Oxidizes in air to form unstable peroxides that may explode spontaneously [Bretherick, 1979 p.151-154, 164]. Water soluble.

Reactivity Profile

2-Phenoxyethanol may react violently with strong oxidizing agents. May generate flammable and/or toxic gases with alkali metals, nitrides, and other strong reducing agents. May initiate the polymerization of isocyanates and epoxides.

Health Hazard

May cause moderate eye irritation and moderate corneal injury. Excessive exposure may cause skin irritation and hemolysis.

Fire Hazard

2-Phenoxyethanol is combustible.

Flammability and Explosibility

Not classified

Pharmaceutical Applications

Phenoxyethanol is an antimicrobial preservative used in cosmetics and topical pharmaceutical formulations at a concentration of 0.5–1.0%; it may also be used as a preservative and antimicrobial agent for vaccines.Therapeutically, a 2.2% solution or 2.0% cream has been used as a disinfectant for superficial wounds, burns, and minor infections of the skin and mucous membranes.
Phenoxyethanol has a narrow spectrum of activity and is thus frequently used in combination with other preservatives,

Industrial uses

2-Phenoxyethanol is used as a preservative in cosmetic formulations at a maximum concentration of 1.0%.
2-Phenoxyethanol is a broad spectrum preservative which has excellent activity against a wide range of Gram negative and Gram positive bacteria, yeast and mould. It is also used as a solvent and, because of its properties as a solvent, it is used in many blends and mixtures with other preservatives.
2-Phenoxyethanol is not registered as a food additive in the EU.
Scognamiglio et al. (ref. 105) reported that 2-phenoxyethanol is a fragrance ingredient used in many fragrance mixtures (see discussion). An ester of 2-Phenoxyethanol, 2-Phenoxyethyl isobutyrate and 2-Phenoxyacetic acid, the main metabolite of 2-Phenoxyethanol, were mentioned in a WHO publication where 43 flavouring agents in food were evaluated (WHO 2003, AR4), however at intakes assessed to be very low in Europe (around 1 µg/kg bw/day).

Contact allergens

Phenoxyethanol is an aromatic ether-alcohol used mainly as a preservative, mostly with methyldibromoglutaronitrile (in Euxyl? K 400) or with parabens. Sensitization to this molecule is very rare.

Pharmacokinetics

This substance has broad-spectrum antimicrobial activity against bacteria, yeasts, and mold .

Side Effects

2-phenoxyethanol is a colorless or straw-colored oily liquid with slight solubility in water but soluble in ethanol and is used as an immersion anesthetic. This agent has bactericidal and fungicidal properties and has been used as a topical anesthetic. This agent can provide deep stages of anesthesia and is relatively inexpensive. Nevertheless, it has no other significant advantages over other drugs. Using 2-phenoxyethanol can elicit several side effects, such as decreased respiratory and heart rate, reduced blood pressure and blood oxygenation, alterations of blood parameters, and elevated plasma levels of adrenaline, glucose, and cortisol, as shown in bighead carp. In addition, sustained and prolonged exposure to 2-phenoxyethanol can cause neuropsychological syndrome in handlers[1].

References

[1] Almut Khler, Karin Finger-Baier, Luis Antunes. "Chapter 16 - Anesthesia, restraint and analgesia in laboratory fishes." Anesthesia and Analgesia in Laboratory Animals (Third Edition) (2023): 393-409.

Safety Profile

Moderately toxic by ingestion and skin contact. A skin and severe eye irritant. Mutation data reported. Some glycol ethers have dangerous human reproductive effects. Combustible when exposed to heat or flame; can react vigorously with oxidizing materials. When heated to decomposition it emits acrid smoke and irritating fumes. To fight fEe, use CO2, dry chemical. Used as a solvent for ester-type resins. See also GLYCOL ETHERS.

Safety

Phenoxyethanol produces a local anesthetic effect on the lips, tongue, and other mucous membranes. The pure material is a moderate irritant to the skin and eyes. In animal studies, a 10% v/v solution was not irritant to rabbit skin and a 2% v/v solution was not irritant to the rabbit eye.Long-term exposure to phenoxyethanol may result in CNS toxic effects similar to other organic solvents.Safety issues related to preservatives used in vaccines, including 2-phenoxyethanol have been reviewed.Contact urticaria has been reported upon exposure to 2-phenoxyethanol-containing cosmetics.
The US FDA has recommended avoiding at least one topical product containing phenoxyethanol due to concerns over inadvertant exposure to nursing infants.
LD₅₀ (rabbit, skin): 5 g/kg
LD₅₀ (rat, oral): 1.26 g/kg

Metabolism

The fate of phenoxyethanol in rats and humans has been investigated . The rate of intestinal absorption was rapid, with 60-70% of the excreted (14)C detected at 3 hours and > 95% of the total 4-day urinary (14)C detected within the first 24 hr. Trace amounts of radioactivity were detected in feces. Four days after dosing, only trace amounts of radioactivity remained in the carcass, primarily in the liver (< 0.2% of the dose), fat and muscle. At the 4 day point, the (14)C concentration in blood was measured to be only 0.001 .
The major metabolite of phenoxyethanol is phenoxyacetic acid .

storage

Aqueous phenoxyethanol solutions are stable and may be sterilized by autoclaving. The bulk material is also stable and should be stored in a well-closed container in a cool, dry place.

Incompatibilities

The antimicrobial activity of phenoxyethanol may be reduced by interaction with nonionic surfactants and possibly by absorption by polyvinyl chloride.The antimicrobial activity of phenoxyethanol against Pseudomonas aeruginosa may be reduced in the presence of cellulose derivatives (methylcellulose, sodium carboxymethylcellulose, and hypromellose (hydroxypropylmethylcellulose)).

Regulatory Status

Included in the FDA Inactive Ingredients Database (topical preparations). Included in nonparenteral medicines licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.
Under European regulations for cosmetics (76/768/EEC), the maximum authorized concentration (MAC) of 2-phenoxyethanol is 1.0%.