Pentane-1,2-diol

Endpoint summary

Description of key information

Repeated dose toxicity:
- oral: NOAEL = 1000 mg/kg bw (OECD 408; OECD 422, Analogy CAS 584-03-2)
- dermal (local): NOAEL = 700 mg/kg bw (OECD 411, Analogy CAS 6920-22-5)
- dermal (systemic): NOAEL = 1000 mg/kg bw (OECD 411, Analogy CAS 6920-22-5)

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

10.9 mg/cm²

Additional information

1,2 pentanediol was tested in an oral repeated dose toxicity study according to OECD 408. Furthermore, there are additional information available for the structural closely related substances 1,2 butandiol (CAS 584-03-2) and 1,2 hexanediol (CAS 6920 -22 -5):

 

In an oral repeated dose toxicity study according to OECD 408, 1,2-Pentanediol was administered by gavage to groups of 10 male and 10 female Wistar rats at dose levels of 0 mg/kg bw (drinking water served as vehicle control), 50 mg/kg bw/d, 250 mg/kg bw/d and 1000 mg/kg bw/d over a period of 3 months (BASF SE, 2013). In addition to the required examinations special attention was given to the reproductive organs of male and female animals. Food consumption and body weights were determined weekly. The rats were examined for signs of toxicity or mortality at least once a day. In addition, the rats were daily examined for any clinically abnormal signs. Detailed clinical examinations in an open field were conducted prior to the start of the administration period and weekly thereafter. Ophthalmological examinations were performed before the beginning and at the end of the administration period. For at least 3 weeks an estrous cycle determination was performed. Beside this, a functional observational battery (FOB) as well as measurement of motor activity (MA) were carried out at the end of the administration period. Clinicochemical and hematological examinations as well as urinalyses were performed towards the end of the administration period. After the administration period all rats were sacrificed and assessed by gross pathology, followed by histopathological examinations. The administration of 1,2-Pentanediol by gavage to male and female Wistar rats for 3 months did not cause test substance-related adverse signs of systemic toxicity. Therefore, the no observed adverse effect level (NOAEL) was 1000 mg/kg bw/d in male and in female Wistar rats.

1,2 butanediol (CAS 584-03-2) was tested in an OECD Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test (OECD Guideline 422; ) in accordance with GLP. 10 rats/sex (Crj:CD (SD)) were administered 0, 40, 200 and 1000 mg/kg bw/day 1,2 butanediol in distilled water by gavage. Due to the test procedure the administration was 42 days for the males and 37 days for the females (day 14 before mating to day 3 of lactation).

There were no deaths throughout the observation period of 42 days. Body weight, food consumption, hematology parameters, clinical chemistry parameters, organ weight, or pathological examination between the treated and control animals did not show any visible differences. Transient hypolocomotion and hypopnea at the 1000 mg/kg was observed in females. This effect was not considered to be systemically adverse as it is of transient nature and there were no other concurrent effects including pathology. Beyond this, any sex difference is not plausible concerning this clinical sign. Therefore, the systemic repeated dose NOAEL of 1,2 butane diol is 1000 mg/kg/day for male and female rats.

A dose of 0, 350, 700 and 1000 mg/kg 1,2 hexanediol was applied onto the shaved skin of 10 ten Srague Dawley rats per sex and dose in a 90 day dermal toxicity study according to OECD 411 and GLP. The study was including additional mal rat fertility parameters (Sperm count and Sperm motility and morphology examination) and FOB. 

Daily dermal administration of the test item to Sprague-Dawley rats for 91-93 days was associated with treatment-related rough coat, fur staining, and slight dermal irritation at 1000 mg/kg/day. Treated skin changes included a low incidence of slight focal erythema/demal thickening observed at necropsy and minimal epidermal hyperplasia and hyperkeratosis observed microscopically. The microscopic changes observed would not be expected to progress to ulceration or chronic skin damage. A mild increase in urine protein in females at 1000 mg/kg bw/day and mild changes in other urine parameters were observed but taken together with a mild increase in total leucocyte count this suggests rather a hidden infection than a test article-related effect at this dose level. Not any adverse effect was reported from FOB or additional male fertility examination and histopathology. The systemic dermal NOAEL of this 90 day study is 1000 mg/kg as systemic effects describe above are not considered to be treatment related. The local dermal NOAEL is 700 mg/kg/day due to the local effects described above.

Justification for classification or non-classification

Classification is not warranted according to the criteria of EU Directive 67/548/EEC and EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.