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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Link to relevant study record(s)

Description of key information

A theoretical assessment has been prepared (see below)

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential
Absorption rate - oral (%):
100
Absorption rate - dermal (%):
10
Absorption rate - inhalation (%):
10

Additional information

Toxicokinetics

 

Carbamic acid ester is a diol with a molecular weight of 320 g/mol. The substance is highly water soluble and its partition coefficient logPow was determined to be 1.1. The vapor pressure of the substance is low.

 

Absorption

Absorption is a function of the potential for a substance to diffuse across biological membranes. In addition to molecular weight the most useful parameters providing information on this potential are the octanol/water partition coefficient (logPow) value and the water solubility.

 

Oral

In general, a molecular weight < 500 is favorable for absorption via the biological membranes of the gastrointestinal tract (GI). Water soluble substances with a log Pow between -1 and 4 will readily dissolve into the gastrointestinal fluids. However absorption of hydrophilic substances by passive diffusion may be limited by the rate at which the substance partitions out of the gastrointestinal fluid.

Based on its physico-chemical properties Carbamic acid ester is expected

to be easily absorbed. The available acute oral toxicity study shows that the substance is of very limited toxicity.

 

Dermal

As is the case for oral absorption, dermal absorption depends also on molecular size, water solubility and logPow. With an average molecular weight of < 500 g/mol and a high water solubility, it is expected that Carbamic acid ester will not be able to penetrate the stratum corneum and subsequently will not become systemically available by passage of the epidermis.

This is supported by the results of the acute dermal study with of the substance showing no systemic effects or mortality after application of 2000 mg/kg bw. Therefore it is concluded that there are no indications for absorption and 10% dermal absorption will be used in risk assessment (default value).

 

Inhalation

Based on the logPow and water solubility respiratory absorption is expected to be low (set at 10% as default value). Although the substance is used in solution and inhalation via aerosols might occur, the uses during the whole life cycle are not expected to release vapors or aerosols/mists containing respirable and/or inhalable droplets. Therefore exposure and concomitant uptake via inhalation can be excluded.

 

Metabolism

When is absorbed, it is expected to be metabolized. As the molecule contains two carbamate like entities, it is expected that the substance would hydrolyse to a certain extent either spontaneously or via specific esterases. A hydrolysis study at pH 2, 4, 6 and 9, however, did not show any abiotic hydrolysis (t1/2 > 1 year), which is in line with the findings for carbamates in general where it is not known to what extent hydrolysis contributes to the detoxification (EHC 64).

No data on mammalian metabolism are available on Carbamic acid ester, but in case of esterase activity, it would be expected that the substance is degraded to propylene glycol, carbon dioxide and the amine. The proportion of the enzymatic breakdown has not been assessed. 

Excretion 

The main route of excretion of the metabolites after oral administration is expected to be via urine.

No bioaccumulation of the test substance or its metabolites is expected.

Conclusion

The uptake of Carbamic acid ester via the oral route is expected to be extensive with consequent metabolism. For the dermal and inhalation route uptake is expected to be limited, but any absorbed parent compound is expected to be metabolized. The hazard assessment of the parent and especially of the metabolites shows low toxicity.