6.0
ISS Score
B — Acceptable — low-moderate concern
↑ Higher = Safer
Environmental
(ESS)
(ESS)
—
Confidence
(CSS)
(CSS)
—
antiseptic · preservative · flavoring agent · fragrance component
Thymol
Also known as: Thymol, 2-Isopropyl-5-methylphenol, Thyme oil phenol
Molecular Formula
C10H14O
Molecular Weight
150.22 g/mol
Category
antimicrobial agent
Bottom Line: Thymol is generally considered safe for use in various applications, though its concentration and formulation should be monitored.
Quick Answer
✔ Generally Safe If:
- used in low concentrations
- applied topically with no irritation
- used in food products within regulatory limits
⚠ Use with Awareness If:
- you have sensitive skin or allergies
- using in combination with other active ingredients
- consuming in large quantities
✕ Avoid If:
- pregnant or breastfeeding without consulting a doctor
- you have a known allergy to thyme or related compounds
- using in high concentrations in cosmetics
Chemical Properties
| Property | Value |
|---|---|
| Molecular Formula | C10H14O |
| Molecular Weight | 150.22 g/mol |
| Melting Point | 51.5°C |
| Boiling Point | 231.0°C |
| Solubility | moderately soluble (in ethanol) |
| Density | 0.9699 g/cm³ |
| Log P | 3.3 |
Common Use Cases
5 Categories
Cosmetic
Facial cleansers, antiseptic creams, shampoos. Use in low concentrations to avoid skin irritation.
Food
Herbal teas, flavoring agents, preservatives. Generally safe in food at regulated levels.
Pharmaceutical
Antiseptic solutions, cough syrups. Consult a healthcare provider for medicinal use.
Household
Cleaning agents, disinfectants. Use as directed to ensure safety.
Supplement
Thymol capsules, herbal extracts. Consult a healthcare professional before use.
Safety by Route of Exposure
dermal
dermal
Risk Level: Low
Thymol is generally well tolerated on the skin, but may cause irritation in sensitive individuals.
oral
oral
Risk Level: Moderate
Ingestion of thymol can lead to gastrointestinal irritation and toxicity at high doses.
inhalation
inhalation
Risk Level: Low to Moderate
Inhalation of thymol vapors may cause respiratory irritation in some individuals.
ocular
ocular
Risk Level: High
Thymol can cause significant irritation and damage to the eyes upon contact.
Who Should Use or Avoid
⚠ Higher Risk Groups
- infants_children — Higher risk of severe reactions due to sensitivity.
- pregnant — Limited safety data; potential risks not fully understood.
- sensitive_skin — Increased likelihood of skin irritation.
✔ Well-Tolerated Groups
- general_adult — Typically well tolerated with proper use.
- elderly — Generally well tolerated, but monitor for sensitivity.
- breastfeeding — Use with caution; consult healthcare provider.
Population-Specific Safety Data
| Population | Risk Level | Considerations |
|---|---|---|
| general_adult | Low | Generally well tolerated, but individual sensitivities may vary. |
| pregnant | Moderate | Limited data on safety during pregnancy; potential risks are not fully understood. |
| infants_children | Very High | Higher sensitivity to thymol; potential for severe reactions. |
| breastfeeding | Low to Moderate | Limited data on excretion in breast milk; caution is advised. |
| elderly | Low | Generally well tolerated, but may have increased sensitivity. |
| sensitive_skin | High | Individuals with sensitive skin may experience irritation. |
Toxicology Data
3 Endpoints
Thymol is recognized for its antimicrobial properties, with various safety assessments supporting its use.
| Endpoint | Value | Test Method | Interpretation | Source |
|---|---|---|---|---|
| LD50 Oral | 18600 mg/kg | Rat - Oral gavage | Low acute toxicity | CIR Safety Assessment (2012) |
| Skin Irritation | non-irritating | Human patch test | No significant irritation observed | CIR Safety Assessment (2012) |
| Sensitization | not sensitizing | Human patch test | No sensitization reactions noted | CIR Safety Assessment (2012) |
Data Quality: All toxicology values are sourced from verified regulatory assessments (CIR, SCCS, ECHA REACH) following OECD test guidelines. Values are used to calculate the Ingredient Safety Score (ISS).
Scientific Evidence
Key Assessments
Thymol is recognized for its antimicrobial properties, with various safety assessments supporting its use.
- Effective against bacteria and fungi.
- Regulatory bodies have set safe usage limits.
- Potential irritant at high concentrations.
Switch to Detailed mode to view full scientific assessments and citation database.
CIR
Report: Safety Assessment of Thymol
Year: 2012
Conclusion: Thymol is safe for use in cosmetics at concentrations up to 1%.
View Full Report →
EFSA
Report: Scientific Opinion on Thymol
Year: 2018
Conclusion: Thymol is safe for use as a food additive within specified limits.
View Full Report →
FDA
Report: Thymol in Food and Cosmetics
Year: 2020
Conclusion: Generally recognized as safe when used appropriately.
View Full Report →
Regulatory Status
Global
Thymol is permitted for use in cosmetics and food across major jurisdictions with specific limits. Switch to Detailed mode for full regulatory breakdown.
US
FDAPERMITTED
Use within established limits.
EU
European CommissionPERMITTED
Limited to specific applications.
UK
UK GovernmentPERMITTED
Use in accordance with safety guidelines.
CA
Health CanadaPERMITTED
Follow established safety limits.
Frequently Asked Questions
Thymol is generally safe for skin use in low concentrations, but patch testing is recommended.
Yes, thymol can be used in food products within regulated limits set by authorities.
Potential side effects include skin irritation or allergic reactions in sensitive individuals.
Version History
Audit Trail
| Version | Date | ISS Score | What Changed |
|---|---|---|---|
| 1.0.0 - Initial enrichment | 2026-04-13T08:04:55.609880Z | — | Initial data enrichment via 3-phase structured outputs |
⚠ Important Notice: This information is for educational purposes only and does not constitute medical, professional, or regulatory advice. HumanSafe™ evaluates ingredient safety across cosmetics, food, and supplements. Scores are exposure-route and context-specific. Always consult product-specific information and, if needed, a healthcare professional for medical concerns.