Safety evaluation of certain food additives - ipcs inchem

POLYDIMETHYLSILOXANE (addendum) 167
Table 1. Comparison of absorption experiments with PDMS
United States Environmental Protection
Agency (2000, 2001)
Lukasiak & Falkiewicz (2000)
Test article 350 cSt, 10 cSt [ 14C]PDMS 300 cSt, 15 000 Da PDMS
Species F344 rats Wistar rats
Dose 1000 mg/kg bw (oral gavage) 5% PDMS, cyclo-PDMS (granulated
feed diet)
Period Single oral dose 12 days
Method Liquid scintillation analysis
Whole-body autoradiography analysis
1H NMR
Results PDMS, 10 cSt and 350 cSt, was excreted Siloxanes were detected in blood
unchanged in the faeces, with little
absorption, 96 h post-dosing
samples
2.2 Toxicological studies
2.2.1 Acute toxicity
No new data were available.
2.2.2 Short-term studies of toxicity
PDMS fluids with a viscosity of 35 cSt or 1000 cSt were evaluated for
palatability at various concentrations in ground rodent chow. Groups of CD-1 mice
(six per sex per group) were given 1, 5 or 10% PDMS fluid in food (10 000, 50 000
and 100 000 mg/kg diet) for 28 days. No deaths, changes in behaviour or changes
in mean body weights were observed. Statistically significant increases in food consumption
were observed in the 5% and 10% PDMS fluid groups. No anal leakage,
oily coats or changes in faecal consistency were observed in mice given a 1% diet
of 35 cSt or 1000 cSt PDMS. There was slight anal leakage in the 5% 35 cSt PDMS
group, but not in the 5% 1000 cSt PDMS group. Anal leakage was slight to severe
in the 10% 35 cSt PDMS group and normal to moderate in the 10% 1000 cSt PDMS
group. There were no changes in faecal consistency in these 5% and 10% PDMS
groups (United States Environmental Protection Agency, 1994c).
The potential toxic effects of 10 cSt and 350 cSt PDMS were evaluated in a
28-day study in F344 rats at dietary concentrations of 10 000, 25 000, 50 000 and
100 000 mg/kg. An increased incidence (onset and area) of corneal opacities was
observed in all treated groups. Test article–related corneal lesions (hyperplasia,
haemorrhage, granulomatous inflammation and suppurative inflammation) were
observed microscopically in males and females given PDMS in the diet at 50 000
and 100 000 mg/kg for 10 cSt PDMS and at all concentrations for 350 cSt PDMS.
Other test article–related effects included matting of the fur in males and females
at 50 000 and 100 000 mg/kg diet, increased mean food consumption in males