Name: Phenoxyethanol
CAS No: 2-Phenoxyethanol [122-99-6]
BP: Phenoxyethanol PhEur: Phenoxyethanol USP-NF: Phenoxyethanol
Arosol; Dowanol EPh; Emeressence 1160; ethyleneglycol monophenyl ether; b-hydroxyethyl phenyl ether; 1-hydroxy-2-phenoxyethane; Phenoxen; Phenoxetol; phenoxyethanolum; bphenoxyethyl alcohol; Phenyl Cellosolve.
2-Phenoxyethanol [122-99-6]
C8H10O2 138.16
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.(1,2) 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.(3–5) Phenoxyethanol has a narrow spectrum of activity and is thus frequently used in combination with other preservatives, see Section 10.
Phenoxyethanol is a colorless, slightly viscous liquid with a faint pleasant odor and burning taste.
See Table I.
Acidity/alkalinity pH = 6.0 for a 1% v/v aqueous solution. Antimicrobial activity Phenoxyethanol is an antibacterial preservative effective over a wide pH range against strains of Pseudomonas aeruginosa and to a lesser extent against Proteus vulgaris and other Gram-negative organisms. It is most frequently used in combination with other preservatives, such as parabens, to obtain a wider spectrum of antimicrobial activity.(6–8) See also Section 12. For reported minimum inhibitory concentrations (MICs) see Table II.(9,10) Autoignition temperature 1358C Boiling point 245.28C Dissociation constant pKa = 15.1(11) Flash point 1218C (open cup) Melting point 148C Partition coefficients Octanol : water = 1.16;(12) Isopropyl palmitate : water = 2.9;(13) Mineral oil : water = 0.3;(13) Peanut oil : water = 2.6.(13) Refractive index nD 20 = 1.537–1.539 Solubility see Table III. Specific gravity 1.11 at 208C
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.
The antimicrobial activity of phenoxyethanol may be reduced by interaction with nonionic surfactants and possibly by absorption by polyvinyl chloride.(14) The antimicrobial activity of phenoxyethanol against Pseudomonas aeruginosa may be reduced in the presence of cellulose derivatives (methylcellulose, sodium carboxymethylcellulose, and hypromellose (hydroxypropylmethylcellulose)).(15)
Phenoxyethanol is prepared by treating phenol with ethylene oxide in an alkaline medium.
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.(10) Long-term exposure to phenoxyethanol may result in CNS toxic effects similar to other organic solvents.(16) Safety issues related to preservatives used in vaccines, including 2-phenoxyethanol have been reviewed.(17) Contact urticaria has been reported upon exposure to 2-phenoxyethanolcontaining cosmetics.(18) The US FDA has recommended avoiding at least one topical product containing phenoxyethanol due to concerns over inadvertant exposure to nursing infants.(19) LD50 (rabbit, skin): 5 g/kg(20) LD50 (rat, oral): 1.26 g/kg(12)
Observe normal precautions appropriate to the circumstances and quantity of material handled. Phenoxyethanol may be irritant to the skin and eyes; eye protection and gloves are recommended.
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%.(21)
Chlorobutanol; chlorophenoxyethanol; phenoxypropanol. Chlorophenoxyethanol Empirical formula C8H9ClO2 Molecular weight 172.60 CAS number [29533-21-9] Phenoxypropanol Empirical formula C9H12O2 Molecular weight 152.18 CAS number [4169-04-4] Synonyms 1-Phenoxypropan-2-ol.
Aqueous solutions are best prepared by shaking phenoxyethanol with hot water until dissolved, followed by cooling and adjusting the volume to the required concentration. The EINECS number for phenoxyethanol is 204-589-7. The PubChem Compound ID (CID) for phenoxyethanol is 31236.