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Description of key information

Key value for chemical safety assessment

Bioaccumulation potential:
low bioaccumulation potential
Absorption rate - oral (%):
50
Absorption rate - dermal (%):
50
Absorption rate - inhalation (%):
100

Additional information

Assessment of the toxicokinetic behavior

 

Since no toxicokinetic studies are available for 1,3-Propanediol, 2,2-dimethyl-, 1,3-diacetate (CAS 13431-57-7), the following assessment is based on the available physicochemical properties and results from other toxicological studies.

 

Physical chemical properties

1,3-Propanediol, 2,2-dimethyl-, 1,3-diacetate is a clear, colourless, homogenous liquid at 20 °C and 1013.25 hPa with a molecular weight of 188.22 g/mol. The test item has a high water solubility of 14.3 g/L at 20.0°C. The log Kow was determined to be 1.9 at 23°C. The test substance has a melting point of -10°C and a boiling point of 219.3°C at 1013.25 hPa. Its relative density is 1.0127 at 20°C. Due to the low vapour pressure of the test substance (0.06 hPa at 20 °C, 0.09 hPa at 25 °C), the volatility of the substance is rather low. The test substance contains ester groups which are susceptible to hydrolysis under alkaline conditions or in presence of specific enzymes.

 

Adsorption

Gastrointestinal absorption:

According to structural properties, enzymatic hydrolysis is expected, indicating that the substance might not be present in the GI tract for the time required for absorption. On the other hand, the small molecular weight of < 500 g/mol, and the moderate log Kow of 1.9 make the test item favourable for absorption in the GI tract. Furthermore, the test substance has a high water solubility. In the gastrointestinal tract absorption of small water-soluble molecules (molecular weight up to around 200 g/mol) occurs through aqueous pores or carriage of such molecules across membranes with the bulk passage of water. In line with this, single and repeated dosing via the oral route resulted in systemic toxic effects in rats. In an acute oral toxicity study no mortality occurred up to 2000 mg/kg bw but transient clinical sings of toxicity like impaired general state, piloerection and dyspnea were observed at 300 and 2000 mg/kg bw within 2-4 hours after administration. Repeated dosing with 1000 mg/kg bw/day caused imbalances in haematology and clinical chemistry parameters in males. It is therefore assumed that the test substance or its possible metabolites become systemically available after absorption along the gastro-intestinal tract.

Respiratory absorption:

Due to the low vapour pressure of the test substance (0.06 hPa at 20 °C, 0.09 hPa at 25 °C), the volatility of the substance is rather low and inhalation exposure to vapors is hence considered to be also low.

Dermal absorption:

With a low vapour pressure, the test substance will not evaporate in significant amounts from the skin and will be available for absorption. The molecular weight of < 500 g/mol, the high water solubility and the moderate log Kow of 1.9 favour dermal uptake. 

Distribution and Accumulation

Since the test substance is a relatively small water-soluble molecule, it probably diffuses through aqueous channels and pores. Therefore, a distribution into different organs is assumed. Due to the moderate log Kow of 1.9 and the high water solubility, the test substance is unlikely to accumulate in adipose tissue with the repeated intermittent exposure patterns normally encountered in the workplace but may accumulate if exposures are continuous.

 

Metabolism

Using the OECD toolbox vs.4.2, the in vivo Rat metabolism simulator provided 4 potential simulated metabolites, as well as 1 simulated skin metabolite. Studies assessing genotoxicity (Ames test; BASF, 2017; HPRT test, BASF, 2018; MNT, BASF, 2018) were negative, i.e. there is no indication of a reactivity of the test substance or its metabolites with macromolecules under the chosen test conditions.

No further data available.

 

Excretion

No data available.

Based on the molecular weight of the parent compound and its water solubility, it is conjectured that the test substance would probably primarily undergo a renal elimination.