Pentane-1,5-diol

Endpoint summary

Description of key information

1,5 pentandiol is of low acute toxicity via all routes of exposure. The following lethal doses after acute exposures have been determined in the key studies:
- oral: LD50 = ca. 10000 mg/kg bw
- dermal: LD50 > 19800 mg/kg bw
- inhalative: no deaths within 7 h exposure to saturated vapor atmosphere(IRT)

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

10 000 mg/kg bw

Acute toxicity: via dermal route

Endpoint conclusion

Dose descriptor:

LD50

Value:

19 800 mg/kg bw

Additional information

Acute oral toxicity was analyzed in a study, which was in large part equivalent to methods described in OECD guideline 401 (BASF, 1979). Two female Sprague-Dawley rats received doses of 1000 and 4640 mg/kg bw pentane-1,5-diol, while five males and five females were dosed by gavage with 6810 and 10000 mg/kg bw. Although three males of the highest dose group died within the 14 day observation period and some clinical signs including acute dilatation and congestive hyperemia were noted, the LD50 could be determined as ca. 10000 mg/kg bw.

In another study, five Carworth-Wistar rats per sex and dosed received pentane-1,5-diol by gastric intubation, resulting in a LD50 of 5890 mg/kg bw (Smyth, 1962).

The LD50 was estimated to be 2000 mg/kg bw for unspecific sex in rats, which was also confirmed by QSAR calculation (Frankenfeld, 1975; Wang, 1998). In another study the LD50 was found to be 6300 mg/kg bw for rabbits and guinea pig (Unknown, 1973).

To assess the acute inhalative toxicity, an inhalation risk test was conducted which was in large part equivalent to OECD guideline 403 (BASF, 1979). Six male and female Sprague-Dawley rats were exposed to saturated atmosphere of a vapor with 0.11 mg/kg pentane-1,5-diol for seven hours. Since no mortality as well as no obvious clinical signs was observed, subsequent calculation let to a LC0 of 0.078 mg/m3 air.

No mortality was also noted in another study, where six male and female albino rats were exposed to a vapor for eight hours (Smyth, 1962).

Acute dermal toxicity was evaluated in a study where 20 ml of pure pentane-1,5-diol was applied to the clipped skin of four New Zealand White rabbits under occlusion by an impervious plastic film (Smyth, 1962). Since no mortality was observed, the LD50 was >20 ml/kg bw corresponding to >19800 mg/kg bw.

In addition, five NMRI mice per sex and dose were intraperitoneal injected with doses of 1470, 2150, 3160 and 4640 mg/kg bw (BASF, 1979). Due to observed mortality in the 14 day observation period, the LD50 was estimated to be in range of 2100 – 3200 mg/kg bw.

In another study, a LD50 of 2246 mg/kg bw was found when six female ICR mice received pentane-1,5-diol by intraperitoneal injection (Holman, 1979).

Beside this, the LD50 in male Sprague-Dawley rats was found to be 3509 mg/kg bw after intraperitoneal injection of various doses (McCreery, 1978)

Justification for classification or non-classification

Due to the LD50 values obtained in several studies for acute oral, dermal and inhalative toxicity, no classification is required.