1-ethoxypropan-2-ol

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Effect on fertility: via inhalation route

Dose descriptor:

NOAEC

4 250 mg/m³

Additional information

In a guideline and GLP study, the reproductive toxicity of methoxypropanol (a close structural analogue of ethoxypropanol) was studied in male and female SD rats exposed by inhalation to 0, 300 1,000 or 3,000 ppm vapours for 10 days prior to mating and 7 d/wk during mating, gestation and lactation for 2 generations. Marked parental toxicity was seen at 3,000 ppm, as evidenced by changes in various organ and body weights (relative/absolute) of the first and second generation males and females, in particular of the testes and ovaries. In females, toxicity was accompanied by decreased fertility, lengthened oestrous cycle, decreased ovarian weight and histopathological ovarian atrophy. Embryotoxicity and foetotoxicity occurred only at maternally toxic doses. No reproductive/neonatal effects were observed at 1000 ppm, a concentration which caused less marked , but significant body weight effects without sedation. Based on these findings the NOEL for reproductive/neonatal effects was 1000 ppm, and that for parental toxicity was 300 ppm. Equivalent airborne concentrations of ethoxypropanol are 4.25 and 1.275 mg/L, respectively.

An extensive justification for read across is contained in the read across justification attached to chapter 13 of this dossier.

Short description of key information:
Inhalation NOEC for reproductive / neonatal effects (extrapolated from analogue): ~ 1000 ppm (4.25 mg/L)
Inhalation NOEC for parental toxicity (extrapolated from analogue): ~ 300 ppm (1.3 mg/L)

Effects on developmental toxicity

Description of key information

Inhalation NOAEC for developmental effects: >= 2000 ppm (8.5 mg/L)
Inhalation NOAEC for maternal toxicity: >= 100 ppm (0.425 mg/L)

Effect on developmental toxicity: via inhalation route

Dose descriptor:

NOAEC

8 500 mg/m³

Additional information

In a guideline and GLP developmental toxicity study in rats, whole body inhalation exposure to ethoxypropanol vapour at concentrations up to 2000 ppm on Days 6-15 of gestation did not produce evidence of developmental effects (based on uterine and litter data, and foetal development). Reduced weight gain and clinical signs were noted in maternal animals exposed to 450 ppm or 2000 ppm. No effects were noted in maternal animals exposed to 100 ppm. Based on these results the following NOAECs for developmental toxicity in the rat are established for ethoxypropanol vapour: NOAEC (maternal) >= 100 ppm; NOAEC (developmental) >= 2000 ppm.

In a guideline and GLP developmental toxicity study in rabbits, whole body inhalation exposure to ethoxypropanol vapour at concentrations up to 1200 ppm on Days 6-18 of gestation did not produce evidence of developmental effects (based on uterine and litter data, and foetal development). A slight reduction in mean food consumption and an initial retardation in body weight gain (gestation days 6 – 10) was seen in maternal animals exposed to 1200 ppm. No effects were noted in maternal animals exposed to 100 or 350 ppm. Based on these results the following NOAECs for developmental toxicity in the rabbit are established for ethoxypropanol vapour: NOAEC (maternal) >= 350 ppm; NOAEC (developmental) >= 1200 ppm

Justification for classification or non-classification

The direct and indirect evidence for ethoxypropanol indicates that reproductive and developmental toxicity is low. No reproductive toxicity was observed in reliable studies of the methyl analogue of ethoxypropanol in the absence of parental toxicity; no developmental toxicity was observed in reliable rat and rabbit studies of ethoxypropanol. On the bases of these studies it is expected that ethoxypropanol does not meet any of the criteria for classification for this end point.