Benzyl alcohol is an organic aromatic alcohol (C₇H₈O) primarily used as a local anaesthetic, a preservative, and a solvent. It occurs naturally in many plants and fruits—such as jasmine, ylang-ylang, and green tea—but is manufactured synthetically for commercial use.
CAS Number: 100-51-6
Molecular Formula: C7H8O
Molecular Weight: 108.14
EINECS Number: 202-859-9
Because of its unique chemical properties, it is widely utilized across the skincare, pharmaceutical, and consumer product industries
Primary Functions and Uses
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Preservative and Stabiliser: In cosmetics and skincare, it kills bacteria, fungi, and mold. It prevents contamination in products like lotions, face creams, and hair care items.
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Local Anaesthetic: It possesses mild numbing qualities. It is added to topical anti-itch creams, insect bite treatments, and some injectable medications to reduce pain at the injection site.
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Solvent: It helps dissolve other active ingredients, essential oils, and fragrances that are not easily soluble in water.
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Anti-Lice Treatment: In high concentrations (5%), it is an FDA-approved prescription medication used to suffocate head lice by preventing them from closing their respiratory spiracles.
Common Ratios and Safe Limits
Regulatory bodies strictly limit the concentration of benzyl alcohol in consumer goods to ensure safety:
| Product Category
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Maximum Allowed Concentration
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Purpose
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Leave-on Cosmetics
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Up to 1.0%
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Preservative / Fragrance component
|
|
Rinse-off Products
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Up to 1.0%
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Preservative / Fragrance component
|
|
Prescription Lice Lotion
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Exactly 5.0%
|
Active ingredient (suffocation mechanism)
|
Safety Warnings and Risks
While generally recognized as safe for the adult general public in low doses, benzyl alcohol carries specific chemical risks:
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Contact Dermatitis: It is a known skin allergen. People with sensitive skin or eczema may experience itching, redness, hives, or a burning sensation where it is applied.
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The "Gasping Syndrome" (Fatal to Infants): Never use products containing benzyl alcohol on newborns or premature infants. Their immature livers cannot break down the chemical, leading to a fatal toxic accumulation known as gasping syndrome, characterized by severe respiratory failure and metabolic acidosis.
- Eye Irritation: In high concentrations or accidental splashes, it causes immediate burning, redness, and potential corneal injury
Melting point: -15 °C
Boiling point: 205 °C
Density: 1.045 g/mL at 25 °C(lit.)
vapor density: 3.7 (vs air)
vapor pressure: 13.3 mm Hg ( 100 °C)
refractive index: n20/D 1.539(lit.)
FEMA: 2137 | Benzyl Alcohol (Phenylcarbinol)
Flash point: 201 °F
storage temp.: Store at +2°C to +25°C.
solubility: H2O: 33 mg/mL, clear, colorless
form: Liquid
pka: 14.36±0.10(Predicted)
color: APHA: ≤20
Relative polarity: 0.608
Odor: Mild, pleasant.
Odor Type: floral
Evaporation Rate: 1.8
explosive limit 1.3-13%(V)
Water Solubility: 4.29 g/100 mL (20 ºC)
Merck: 14,1124
JECFA Number: 25
BRN: 878307
