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Synonyms: 1-methyl-4-(1-methylethenyl)cyclohexene, (R); l-Limonene; d-Limonene; dl-Limonene; Dipentene; Acintene DP; Cinene; Dipanol; Unitene; 1-methyl-4-isopropentyl-1-cyclohexene
OSHA IMIS Code Number: L129
Chemical Abstracts Service (CAS) Registry Number: 138-86-3
Other Chemical Abstracts Service (CAS) Registry Numbers: 5989-27-5 (d-Limonene)
NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: GW6360000
Chemical Description and Physical Properties:
colorless to very pale yellow flammable liquid; floats on water
molecular weight: 136.23
molecular formula: C10H16
boiling point: 177°C
melting point: -96.9°C
flash point: 43°C
Potential Symptoms: Irritation of eyes, nose, throat, skin; allergic contact dermatitis
Health Effects: Irritation-Eyes, Nose, Throat, Skin---Mild (HE16); Skin sensitization--- Dermatitis (HE3)
Affected Organs: Eyes, skin
- Limonene is on FDA's list of synthetic flavoring substances and adjuvants that are Generally Recognized as Safe (GRAS) (21 CFR 182.60).
- Oxidation products of limonene that form during handling and storage, rather than limonene itself, are the mediators of irritation and sensitization.
- Although chronic oral administration of d-limonene to rats caused kidney damage and kidney tumors in the males, this effect is thought to have no human relevance (IARC Group 3).
- Metabolized by several hepatic enzymes (CYP2C8, CYP2C9, CYP2C18, CYP2C19, CYP3A4) to carveols (6-hydroxylation) and perillyl alcohols (7-hydroxylation), with CYP2C9 and CYP2C19 showing the greatest activities in human liver microsomes.
- International Chemical Safety Cards (WHO/IPCS/ILO): D-Limonene.
- National Industrial Chemicals Notification and Assessment Scheme (Australia): Limonene. Priority Existing Chemical Assessment Report No. 22, (May) 2002, 130 pp.
- NIOSH Registry of Toxic Effects of Chemical Substances, RTECS #: GW6360000: Cyclohexene, 1-methyl-4-(1-methylethenyl)-, (R)-.
- Karlberg, A.T. and Dooms-Goossens, A.: Contact allergy to oxidized d-limonene among dermatitis patients. Contact Dermatitis 36(40: 201-206, 1997.
- Kleno, J. and Wolkoff, P.: Changes in eye blink frequency as a measure of trigeminal stimulation by exposure to limonene oxidation products, isoprene oxidation products and nitrate radicals. Int. Arch. Occup. Environ. Med. 77(4): 235-243, 2004.
- Matura, M., et al.: Oxidized citrus oil (R-limonene): a frequent skin sensitizer in Europe. J. Am. Acad. Dermatol. 47(5): 709-714, 2002.
- Miyazawa, M., Shindo, M. and Shimada, T.: Metabolism of (+)- and (-)-limonenes to respective carveols and perillyl alcohols by CYP2C9 and CYP2C19 in human liver microsomes. Drug Metab. Dispos. 30(5): 602-607, 2002.
- National Toxicology Program: NTP toxicology and carcinogenesis studies of d-limonene (CAS No. 5989-27-5) in F344/N rats and B6C3F1 mice (gavage studies). Nat. Toxicol. Program Tech. Rep. Ser. 518: 1-165, 1990.
- Pohanish, R.P. (editor): Dipentene. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 1. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 970-972.
Date Last Revised: 01/04/2005
Primary Laboratory Sampling/Analytical Method (SLC1):
- sampling media: Charcoal Tube (100/50 mg sections)
analytical solvent: Carbon Disulfide
maximum volume: 10 Liters
maximum flow rate: 0.2 L/min
current analytical method: Gas Chromatography; GC/FID
method reference: OSHA Analytical Method (OSHA PV2036)
method classification: Partially Validated
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