title: Mineral oil saturated hydrocarbons (MOSH) in female Fischer 344 rats; accumulation of wax components; implications for risk assessment.
abstract: Female Fischer 344 rats were exposed to three MOSH mixtures: oils largely below and above C25(S-C25 and L-C25) and a 1:1 mixture of L-C25 with a wax; doses of 400, 1000 and 4000mg/kg feed were administered during 120days. MOSH were determined by on-line HPLC-GC-FID in liver, spleen, adipose tissue and the carcass. The composition of the hydrocarbons accumulated in the tissues was further analyzed by comprehensive two-dimensional GC (GC×GC). MOSH in the mass range of C26-30were more strongly accumulated than those between C20-25, which does not support the present classification of MOSH differentiating at n-C25for risk assessment. Compared to the total of the MOSH, n-alkanes and n-alkyl monocyclic naphthenes were generally enriched in adipose tissue. In liver and spleen, n-alkanes up to C25were eliminated, but strongly accumulated at around C30. Based on this profile, poor solubility and the melting points, it is hypothesized that crystallization protects these wax components against metabolism and elimination. In the liver, relative retention of n-alkanes decreased again beyond C30, accentuated at high exposure, suggesting reduced absorption. Compared to the animal data, accumulation of n-alkanes from food sources, such as apples, into human tissues seems low, perhaps because of low absorption due to their presence in crystalline form. A series of dominant isoalkanes, accumulated in all tissues analyzed, was characterized, though without proposing a structure. Implications on present regulation of white mineral oil products are discussed.
authors.affiliation: Official Food Control Authority of the Canton of Zurich, Zurich, Fehrenstrasse 15, P.O. Box, CH-8032 Zurich, Switzerland.
authors.forename: Laura
authors.initials: L
authors.lastname: Barp
authors.affiliation: Official Food Control Authority of the Canton of Zurich, Zurich, Fehrenstrasse 15, P.O. Box, CH-8032 Zurich, Switzerland.
authors.forename: Maurus
authors.initials: M
authors.lastname: Biedermann
authors.affiliation: Official Food Control Authority of the Canton of Zurich, Zurich, Fehrenstrasse 15, P.O. Box, CH-8032 Zurich, Switzerland. Electronic address: koni@grob.org.
authors.forename: Koni
authors.initials: K
authors.lastname: Grob
authors.affiliation: Toxalim, INRA, ENVT, INP-EIPurpan, Université de Toulouse, Toulouse, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Blas-Y-Estrada
authors.affiliation: Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, n-0403 Oslo, Norway.
authors.forename: Unni C
authors.initials: UC
authors.lastname: Nygaard
authors.affiliation: Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, n-0403 Oslo, Norway.
authors.forename: Jan
authors.initials: J
authors.lastname: Alexander
authors.affiliation: Toxalim, INRA, ENVT, INP-EIPurpan, Université de Toulouse, Toulouse, France.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Cravedi
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D005260:Female; D006838:Hydrocarbons / Q000633:toxicity*; D008099:Liver / Q000378:metabolism; D008899:Mineral Oil / Q000633:toxicity*; D051381:Rats; D011916:Rats, Inbred F344; D018570:Risk Assessment; D013154:Spleen / Q000378:metabolism; D018675:Toxicity Tests
chemical_list: D006838:Hydrocarbons; D008899:Mineral Oil
keywords: Class I mineral oils; Crystallization of waxes; Granulomas; Mineral waxes; Naphthenes; n-Alkanes