2-Butyne-1,4-diol, polymer with 2-(chloromethyl)oxirane, brominated, dehydrochlorinated, methoxylated

Endpoint summary

Description of key information

The substance showed moderate acute oral toxicity in male rats (LD50 = 1337 mg/kg bw). Regarding inhalation exposure, the 4-hour LC50 is above 5.47 g/m3 for male and female rats.

Additional information

An acute oral toxicity study and an acute inhalation toxicity study are available for assessment. Both studies were performed with Polyol IXOL B251. Polyol IXOL B251 is a mixture consisting of 93-94% Polyol IXOL B350 and 6-7% triethyl phosphate (CAS number: 78-40-0). Based on the available data on triethyl phosphate as summarised in the OECD SIDS of that substance, it is not expected that 6-7% triethyl phosphate as present in Polyol IXOL B251 changes the toxicity profile significantly, i.e., the toxicity profiles of Polyol IXOL B350 and Polyol IXOL B251 are considered similar.

Oral route

The acute oral toxicity of Polyol IXOL B251 was investigated in a GLP compliant study using a protocol similar to OECD guideline 401 (Duphar B.V., 1985a). Single doses of B251 in 1%-tragacanth were given by stomach tube to groups of five male fasted rats. The doses were 625, 1250, 2500 and 5000 mg/kg bw. The animals were weighed one day before and at 2, 7 and 14 days after dosing. Any toxic sign occurringduring the 14-day observation period was recorded. Gross post-mortem examination was done on dead animals and on the survivors at the end of the 14-day observation period.

At 625 mg/kg bw, no mortalities were observed; at 1250 mg/kg bw, 3/5 animals died; at 2500 mg/kg bw: 4/5 animals died and 5000 mg/kg bw: 5/5 animals died. The LD50 was 1337 mg/kg bw. There was a dose-related weight loss in the first days after dosing. Thereafter there was a recovery. The signs were mainly indicative of an effect on the autonomic nervous system (hypothermia, ptosis, diminished respiratory rate, pilo-erection, lacrimation), on the central nervous system (apathy, twitches, diminished alertness and startle response, positional passivity, decreased grooming), on motor coordination (loss of righting reflex, diminished locomotor activity, abnormal gait) and on muscle tone (diminished body tone and limb tone). Autopsy of the rats that died as a result of treatment revealed effects on the gastro-intestinal tract (irritation), kidneys (pale), liver (pale), lymph nodes (congested) and lungs (red spots).

Inhalation route

The acute inhalation toxicity of Polyol IXOL B251 was investigated in a GLP compliant, OECD guideline 403 study in rats (TNO, 2010a). The actual concentration during exposure was 5.47 ± 0.05 g/m³. Body weight was measured just before exposure and weekly thereafter. At necropsy, animals were examined for gross pathological changes. The animals did not show abnormalities during the first two hours of exposure. During the second two hours of exposure all animals showed breathing at a decreased rate. No clinical abnormalities were observed shortly after exposure or during the remainder of the observation period. Body weight gain was as expected for animals of this age and strain.No treatment-related macroscopic abnormalities were found at necropsy. Mortality did not occur. It is therefore concluded that the 4-hour LC50 is above 5.47 g/m³ for male and female rats.

Dermal route

In accordance with column 2 of REACH Annex VIII-X, as acute toxicity studies for the oral and inhalation route are available, no study regarding the dermal route is needed.

Justification for classification or non-classification

Based on the oral LD50 value of 1337 mg/kg bw, the substance has to be classified according to Directive 67/48/EEC as Xn – R22 (Harmful if swallowed). In accordance to EU Classification, Labeling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008, the substance has to be classified for Acute toxicity, Cat. 4 - H302 (Harmful if swallowed). No classification for acute inhalation toxicity is warranted.