1-vinyl-2-pyrrolidone

Endpoint summary

Description of key information

Oral LD50: 834 to 1314 mg/kg bw (male/female rat); 1022 mg/kg bw (male/female rat);
Dermal LD50: between 1043 and 4127 mg/kg bw (male/female rat) in a reliable study, less reliable study result: LD50=560 mg/kg bw (male/female rabbit); Inhalation LC50 = 3070 mg/m3 (male/female rat).

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

1 022 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Dose descriptor:

LC50

Value:

3 070 mg/m³ air

Acute toxicity: via dermal route

Endpoint conclusion

Dose descriptor:

LD50

Value:

2 350 mg/kg bw

Additional information

n-Vinylpyrrolidone (nVP) has been adequately characterized for acute toxicity via oral, dermal, and inhalation routes.  In various non-GLP guideline-equivalent studies, oral LD50 values (male/femal rats) include 834 to 1314 mg/kg bw (European Commission, 2003) and 1022 mg/kg bw (BASF, 1963), dermal LD50 values (male/female rabbits) of >400 mg/kg bw (BASF, 1979) and > 1000 mg/kg bw (HRC, 1978), and the inhalation LC50 (male/female rats) was determined to be 3070 mg/m3 (BASF, 1979).

Justification for classification or non-classification

Acute oral toxicity

Based on a weight of the evidence of the results of acute oral toxicity testing (LD50, rat = 834 to 1314 mg/kg bw), the substance should be classified as Xn; R22 (Harmful if swallowed) under the EU DSD classification criteria (EU Directive 67/548/EEC) and Acute Toxicity, Oral-Category 4 under the EU CLP classification criteria (Regulation (EC) 1272/2008).

Acute inhalation toxicity

Based on the results of acute inhalation toxicity testing (LC50, rat = 3070 mg/m3), the substance should be classified as Xn; R20 (Harmful by inhalation) under the EU DSD classification criteria (EU Directive 67/548/EEC) and Acute Toxicity, Inhalation-Category 4 under the EU CLP classification criteria (Regulation (EC) 1272/2008).

Acute dermal toxicity

The study with rabbits (LD50 = 560 mg/kg bw; FDRL, 1975; cited in EU RAR) lacks important data on conditions of exposure and information on local skin effects or systemic toxicity. Consequently, this study was given reliability 4 (not assignable).

The BASF study with no mortality at 400 mg/kg bw does not provide for sufficient evidence for an LD50 > 1000 mg/kg bw. However, the third study with rats shows indeed that the LD50 is > 1000 mg/kg (2350 mg/kg) when both sexes are combined. Females appeared to be more sensitive with 50% mortality at 1000 mg/kg, but due to the low number per replicate (2) this remains equivocal. A higher sensitivity of female rats is also observed in the inhalation study (Key Study - BASF AG (1979) - Acute toxicity: inhalation, rat).

Based on a weight of evidence of the results of acute dermal toxicity testing (LD50, rabbit of 560 mg/kg-bw and LD50, rat of 1043 to 4127 mg/kg bw), the substance should be classified as Xn; R21 (Harmful in contact with skin) under the EU DSD classification criteria (EU Directive 67/548/EEC). Giving more weight to the two studies with an assignable reliability, CLP classification appears fall in Acute Toxicity, Dermal-Category 4 (EC Regulation 1272/2008).