Citrus Oils: d-Limonene is the major component of the oil extracted from citrus rind. When citrus fruits are juiced, the oil is pressed out of the rind. This oil is separated from the juice, and distilled to recover certain flavor and fragrance compounds. The bulk of the oil is left behind and collected. This is food grade d-Limonene. After the juicing process, the peels are conveyed to a steam extractor. This extracts more of the oil from the peel. When the steam is condensed, a layer of oil floats on the surface of the condensed water. This is technical grade d-Limonene.
In the past decade, the use of d-Limonene has expanded tremendously. Much of the product goes into making paint solids, used to impart an orange fragrance to products, and used as a secondary cooling fluid. But the largest growth segment has been the use of d-Limonene in cleaning products. This has occurred in both industrial uses and in household/institutional products. d-Limonene can be used either as a straight solvent, or as a water dilutable product. (source: Wikipedia.org)
The only microscopic evidence of compound-related toxicity noted in the rats was nephropathy in the males. d-Limonene is one of a diverse group of hydrocarbons that has been shown to induce a unique syndrome of nephropathy in male rats following subchronic or chronic exposure. Based on a review of the literature concerning this effect (U.S. EPA, 1991), EPA´s Risk Assessment Forum concluded that nephropathy in male rats that is associated with alpha- 2u-globulin accumulation in hyaline droplets is not an appropriate endpoint to determine noncancer effects potentially occurring in humans.
d-Limonene is an occupational skin sensitizer. Repeated or prolonged skin contact can cause an allergic skin response (redness, swelling, itching). The allergic response is caused by oxidation products of d-limonene, which are formed upon exposure to air. d-Limonene of very high purity is not expected to produce an allergic response. An 8% solution of d-limonene in petrolatum did not cause an allergic skin response in any of 25 volunteers tested. Five of 67 people who had an allergic skin response to turpentine tested positive to 1% d-limonene. Occupational exposure to celeriac has caused allergic skin responses. d-Limonene, a component of celeriac, is thought to be responsible. Mist and vapour may cause nose and throat irritation. Specific information is not available, but the liquid was a skin irritant in an animal study. Liquid can probably cause irritation. Specific human information is not available, but citrus peel oil, which contains about 90% d-limonene, is an irritant. d-Limonene was a mild to moderate irritant in animal tests. Limonene (isomer not specified) was absorbed through the skin at 100 times the rate of water.
(source: Canadian Centre for Occupational Health & Safety "Cheminfo" database)
Teratogenicity and Embryotoxicity: No human information. Limited evidence of developmental abnormalities in animals at doses that cause maternal toxicity. (source: Canadian Centre for Occupational Health & Safety "Cheminfo" database)
