Evaluation of sensory irritation of delta3-carene and turpentine, and acceptable levels of monoterpenes in occupational and indoor environment.
The standard mouse bioassay was used for obtaining the RD50 (i.e., the concentration that causes a 50% decrease in respiratory frequency) and for estimating the irritation properties of d-delta3-carene (i.e., (+)-delta3-carene) and commercial turpentine. The chemicals studied possess mainly sensory irritation properties similar to the previously studied monoterpenes, pinenes. The irritation potency of d-delta3-carene (RD50 = 1345 ppm) was almost equal to that of d-pinenes. Thus, d-delta3-carene was about four times more potent as a sensory irritant than I-beta-pinene, whereas the difference with I-alpha-pinene was more marked; as a sensory irritant, I-alpha-pinene is almost inactive. Based on sensory irritation potency and physicochemical and structural properties of pinenes and delta3-carene, the potency of a closely related monoterpene, limonene, is discussed. For commercial turpentine, a mixture of monoterpenes (mainly d-delta3-carene, I-beta-pinene, alpha-pinenes, and limonenes), the RD50 (1173 ppm) was the same order of magnitude as those of d-pinenes and d-delta3-carene. Apparently, d-monoterpenes are responsible for the sensory irritation caused by turpentine. In the wood industry and in the indoor air of nonindustrial environments, monoterpenes are thought to be one of the causative agents for irritation symptoms. The occupational exposure limit (OEL) of turpentine (100 ppm in Finland and the United States) is also used for individual monoterpenes, excluding limonene. Using results from this and our previous study, proposed OELs and recommended indoor levels (RILs) for selected monoterpenes and turpentine were determined based on their RD50 values. According to our studies, the present OEL of turpentine (100 ppm; 560 mg/m3) in Finland and in the United States seems to be suitable only for I-pinenes. For d-monoterpenes and turpentine, an OEL about three times lower is suggested. Our results show that recommended indoor levels (RILs) for monoterpenes are high compared to the concentrations measured indoors in nonindustrial environments. Thus, it is very unlikely that monoterpenes alone can cause irritation symptoms in homes or offices under normal conditions.
Kasanen
J P
JP
Department of Environmental Sciences, University of Kuopio, Finland. kasanen@uku.fi
Pasanen
A L
AL
Pasanen
P
P
Liesivuori
J
J
Kosma
V M
VM
Alarie
Y
Y
D000388:Air / Q000032:analysis; D016902:Air Pollution, Indoor / Q000009:adverse effects*; D000758:Anesthesia; D000818:Animals; D000081008:Bicyclic Monoterpenes; D003627:Data Interpretation, Statistical; D007509:Irritants / Q000633:toxicity*; D008168:Lung / Q000473:pathology / Q000503:physiopathology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008958:Models, Molecular; D039821:Monoterpenes; D016273:Occupational Exposure / Q000009:adverse effects*; D015656:Respiratory Mechanics / Q000187:drug effects; D013729:Terpenes / Q000633:toxicity*; D014425:Turpentine / Q000633:toxicity*
D000081008:Bicyclic Monoterpenes; D007509:Irritants; D039821:Monoterpenes; D013729:Terpenes; C030218:3-carene; D014425:Turpentine