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Description of key information

Based on the results of the repeated dose toxicity studies in rats and the overall assessment of the available data, accumulation of CHVE can be excluded.

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential

Additional information

Cyclohexylvinylether (CHVE; CAS-No. 2182-55-0) is a clear, colorless liquid with a density of 0.891 g/cm2 ,a boiling point of 152 °C and a molecular weight of 126.2 g/mol. CHVE has a vapor pressure of 4.2 hPa (20°C) and is of limited water solubility (0.33 g/L).

The main exposure/absorption route for CHVE is inhalative.

In an acute oral toxicity study with CHVE in rats (BASF, 1964) the LD50was determined to be 3100 mg/kg body weight (bw). The clinical signs of toxicity were staggering, dyspnoea and narcosis, necropsy showed no abnormalities. A later acute oral toxicity study in Wistar rats (Bioassay, 2012) showed no mortality up to a dose of 2000 mg/kg bw. Signs of toxicity were impaired and poor general state, dyspnoea, staggering, piloerection, atonia and narcosis. In an acute inhalation toxicity study with an atmosphere that was saturated by CHVE vapor (about 5000 ppm), 2 of 12 animals died after 3 hours and 5 of 12 animals died after 8 hours of exposure (BASF, 1964). The clinical signs of toxicity were irritation of the mucosa with dyspnoea more or less severe in relation to the time of exposure, only slowly reversible narcosis and necropsy findings: distinct pulmonary congestion and congestion of the liver after prolonged inhalation. In another acute inhalation toxicity study (BASF, 2012) with male and female Wistar rats the LC50was estimated to be > 22 mg/L (no mortality). Clinical signs of toxicity comprised depressed and labored respiration, intermittent respiration, unsteady gait and piloerection. In a reproductive toxicity screening study with Wistar rats (OECD 421; BASF, 2012), CHVE was administered via inhalation at concentrations of 0, 100, 500 and 1500 mg/ m3. Main signs of toxicity were observed in males including increased liver weight, centrilobular hepatocellular hypertrophy and increased lung weight at the high dose as well as degeneration of the olfactory epithelia in the nasal cavity at high and mid dose. Repeated dose toxicity of CHVE was evaluated in Wistar rats which were head-nose exposed to dynamic inhalation atmosphere for 6 hours on 5 days per week for 90 days (BASF SE, 2012). The targeted concentrations were 100 mg/m3, 500 mg/m3and 1500 mg/m3. Treatment related effects at the high dose were increased alkaline phosphatase and triglyceride levels as well as absolute and relative liver weights. Histopathology revealed centrilobular hepatocellular hypertrophy and necrosis. Furthermore, the CHVE treated groups showed a degeneration and regeneration of the olfactory epithelium.

Based on the results of these studies as well as on the structure, the molecular weight and the phys./chem. properties, CHVE can be considered to be bioavailable.

CHVE might be metabolized by formation of acetaldehyde and cyclohexanone. Potential hydrolysis in the organism could result in cyclohexanol and acetaldehyde. A comparable metabolism could be shown for other vinylethers, i.e. isobutylvinylether (IBVE, CAS 109‑53‑5) in in vitro studies (BASF, 2006). In these studies IBVE was incubated in gastric acid simulans or in subcellular fraction of rat liver and it could be shown that IBVE hydrolyzed fast in these systems.

There are no indications of genotoxicity of CHVE and its metabolites from the present mutation and cytogenetic tests (Ames-test +/- S9 (BASF SE, 2012), in vitro (BASF SE, 2012) and in vivo (BASF SE, 2012) cytogenetics). Due to the low molecular weight, the chemical structure, the vapor pressure and its presumed metabolism, CHVE and/or its metabolites are expected to be excreted via exhalation and via the urine.

Based on the results of the repeated dose toxicity studies in rats and the overall assessment of the available data, accumulation of CHVE can be excluded.