Commonwealth of Australia 2002
Introduction 1.1Declaration
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- 1.2Objectives
- 1.3Source of information
- 1.4Peer review
1.Introduction1.1DeclarationLimonene and its isomers were declared priority existing chemicals for full assessment by the Minister for Employment, Workplace Relations and Small Business under the Industrial Chemicals (Notification and Assessment) Act 1989 (IC(NA) Act), as amended, by notice in the Chemical Gazette of 1 August 2000. The reasons for the declaration were: the wide use of limonene in cleaning products, available for both industrial and consumer use; the chemicals are skin irritants in both humans and experimental animals and eye irritant in rabbits; and repeated exposure to limonene mainly affects the liver and kidneys. Use of limonene as a solvent will also result in direct exposure to the environment. 1.2ObjectivesThe purpose of the assessment is to:
Use of the word ‘limonene’ in this report refers to the two isomers of limonene (d- and l-) and its racematic form dl-limonene, unless specified. 1.3Source of informationInformation for the assessment was obtained from various sources. Industry
In accordance with the IC(NA) Act, manufacturers and importers of limonene who were manufacturing and/or importing and who wished to manufacture and import whilst limonene was a PEC were required to apply for assessment and supply information. Data supplied by applicants included:
No unpublished data on health or environmental effects of limonene and its isomers were provided by applicants. Information for the assessment was also received from end users, formulators, and from a comprehensive literature search. Literature review The major sources of information on the health effects of limonene were the World Health Organisation (WHO) Concise International Chemical Assessment Document (CICAD) published under the International Programme on Chemical Safety (IPCS) covering limonene and its isomers (IPCS, 1998) and the International Agency for Research on Cancer (IARC) monographs on d-limonene (CAS 5989-27-5) (IARC, 1993; 1999). To enhance the efficiency of the National Industrial Chemical Notification and Assessment Scheme (NICNAS) assessment and provide transparency, the IPCS report (1998) was used as the basis for the hazard assessment, and the health effects sections of the CICAD were scanned into this report (Sections 9, 10, and 11). The primary studies from the IPCS report were not sighted and are indicated with an asterisk (*) in this report. The IPCS report included data available up to 1997. New information available since the IPCS report was identified from on-line searches of a number of publicly available databases. The IPCS report was also used as the basis of the environmental fate and toxicity review. Surveys
Most of the applicants for the assessment on-sell the manufactured/imported limonene and were unable to provide any data on occupational exposure during use of the chemicals. NICNAS therefore conducted a telephone survey in August 2001 to investigate the use patterns, occupational exposure levels, control technologies and environmental exposure to limonene in Australia (NICNAS industry phone survey). Formulators and end users of limonene products participated in the survey by completing a questionnaire (see Appendix 1). Site Visits Information on mode of use and exposure was also obtained through a number of site visits.
2.BackgroundLimonene occurs naturally in certain trees and bushes and is found in a large number of oils, including oils of lemongrass, citronella, palmarosa, cardamon and bergamot, siberian pine needle oil and several other essential oils including turpentine oils of various origins. It is a major constituent of oil of citrus rind, dill oil, oil of cumin, neroli, bergamot and caraway. Limonene is also one of the ingredients in the terpene fraction of tobacco smoke. Limonene and other monoterpenes are released in large amounts mainly to the atmosphere, from both biogenic and anthropogenic sources. The most widespread form is the d-limonene, followed by the racemic form dl-limonene (also called dipentene) and finally l-limonene. d-Limonene was first recovered as a commercial product during the 1941-42 Florida (USA) citrus season, from the steam evaporator condensate in the production of citrus molasses. d-Limonene may be produced by steam distillation of citrus peels and pulp after alkali treatment, followed by fractional distillation. d-Limonene may also be extracted from citrus oils. l-Limonene may be produced by purification of isolated monoterpenes from certain pine needle oils, or synthetically from pinene by acid catalysis. dl-Limonene can be manufactured by mixing equal parts of d- and l-limonene, by thermal isomerization of -pinene or as a by-product of the production of synthetic pine oils.
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