Registration Dossier

Administrative data

Description of key information

Oral LD50 = 132 mg/kg bw

Dermal LD50 = 659 mg/kg bw

Inhalation LC50 = 690 mg/m3

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Dose descriptor:
LD50
Value:
132 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion
Dose descriptor:
LC50
Value:
690 mg/m³

Acute toxicity: via dermal route

Endpoint conclusion
Dose descriptor:
LD50
Value:
659 mg/kg bw

Additional information

1,4 -Butynediol (B3D) has been adequately characterized for acute toxicity via oral, dermal, and inhalation routes.  In various GLP and non-GLP guideline studies, the oral LD50 (male rats) was determined to be 132 mg/kg bw (Jedrychowsi, et. al., 1992), the dermal LD50 (male/female rats) was determined to be 659 mg/kg bw (BG Chemie, 1990), and the inhalation LC50 (male/female rats) was determined to be 690 mg/m3 (BG Chemie, 1996).

Justification for classification or non-classification

Acute oral toxicity

Based on the results of acute oral toxicity testing (LD50, rat = 132 mg/kg-bw), the substance should be classified as T; R25 (Toxic if swallowed) under the EU DSD classification criteria (EU Directive 67/548/EEC) and Acute Toxicity, Oral-Category 3 under the EU CLP classification criteria (Regulation (EC) 1272/2008).

Acute inhalation toxicity

Based on the results of acute inhalation toxicity testing (LC50, rat = 0.690 mg/l), the substance should be classified as T; R23 (Toxic by inhalation) under the EU DSD classification criteria (EU Directive 67/548/EEC) and Acute Toxicity, Inhalation-Category 3 under the EU CLP classification criteria (Regulation (EC) 1272/2008).

Acute dermal toxicity

Based on the results of acute dermal toxicity testing (LD50, rat = 659 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) and Acute Toxicity, Dermal-Category 3 under the EU CLP classification criteria (Regulation (EC) 1272/2008). Regulation (EC) 1272/2008, Annex VI, specifies a minimum classification of Category 4 unless the manufacturer has data that a higher classification is necessary, as in this case.