Feeding Studies in Rats with Mineral Hydrocarbon Food Grade White Oils

Abstract

This investigation compared the effects of feeding rats diets containing food grade white oil processed by either conventional oleum treatment or the more modem method of catalytic hydrogenation. In two separate experiments, male or female Fischer-344 rats were given free access for 90 days to diets containing 0, 10, 100, 500, 5,000, 10,000, or 20,000 ppm of either oleum-treated white oil (OTWO) or hydrotreated white oil (HTWO). There were no mortalities and no adverse clinical signs associated with feeding either white oil. Treatment-related effects evidenced by hematological, clinical chemical, and pathological changes were generally dose-related and more marked in female than in male rats, and the OTWO caused a greater pathological response than the HTWO. Tissue residues of saturated hydrocarbons were up to 5.2 times higher in female rats than in males. Rats fed 5,000 ppm or more of either white oil showed dose-related alterations in several hematological and clinical chemistry variates associated mainly with hepatic damage or functional alteration. At necropsy, mesenteric lymph nodes were enlarged, and increases in weight of liver, kidney, and spleen were significant. Microscopic changes were characterized by multifocal lipogranulomata in mesenteric lymph node and liver. No changes were observed in rats fed OTWO or HTWO for 90 days at dietary concentrations of 10 or 100 ppm, equivalent to a minimum intake of 0.65 and 6.4 mg/kg/day, respectively. Differences in degree of pathological response associated with each oil may have been due to their differences in specification rather than processing method.

Characterization of the toxicological hazards of hydrocarbon solvents

“…The histological findings were limited to evidence of microgranuloma formation in the livers and mesenteric lymph nodes in the animals of the highdose group. The principal objective of this study was to examine the potential for mineral oils to accumulate in the liver and mesenteric lymph nodes, an effect previously reported to occur in F-344 rats but not in rats of other strains or animals of other species (Baldwin et al 1992, Bird et al 1990, Firriolo et al 1995, 1996, Scotter et al 2003. A principal finding was that the hydrocarbons that preferentially accumulated in the liver, leading to granuloma formation, had carbon numbers  C20.…”

Scientific Opinion on Mineral Oil Hydrocarbons in Food

“…However, for the most part this effect was found to be unique to Fischer 344 rats (Baldwin et al, 1992;Firriolo et al, 1995;Smith et al, 1996;Griffis et al, 2010). The liver microgranulomas induced in Fischer 344 rats are associated with T and B lymphocyte influx and sometimes with central necrosis and fibrosis.…”

“…HTWO: hydrotreated white oil, containing alkanes and cyclo alkanes (cyclo-alkanes in higher proportions than OTWO), no or minor amounts of aromatics. Baldwin et al (1992). 2: Baldwin et al (1992) identified hepatic NOELs based on the incidence of slight to moderate Kupffer cell hypertophy, observed in female rats at ≥ 100 mg/kg and ≥ 500 mg/kg for OTWO and HTWO, respectively.…”

“…Baldwin et al (1992). 2: Baldwin et al (1992) identified hepatic NOELs based on the incidence of slight to moderate Kupffer cell hypertophy, observed in female rats at ≥ 100 mg/kg and ≥ 500 mg/kg for OTWO and HTWO, respectively. The CONTAM Panel considered these changes as non adverse and based the hepatic NOAELs on the incidence of liver lipogranulomas (i.e.…”

Scientific Opinion on the re‐evaluation of microcrystalline wax (E 905) as a food additive

“…The Panel noted that subchronic (90-day) feeding studies on a wide range of white oils and waxes were conducted in F344 rats (Baldwin et al, 1992;Smith et al, 1996;Scotter et al, 2003;Griffis et al, 2010). In addition, subchronic studies in Long Evans rats and Beagle dogs on a related white mineral oil are available (Smith et al, 1995).…”