1,1'-[oxybis(ethyleneoxy)]diethylene

Endpoint summary

Description of key information

Absorption by the oral, dermal and inhalation routes is expected. Moreover, distribution through extracellular body fluids is likely. Excretion will most likely occur via the urine. No bioaccumulation is expected.

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Additional information

Toxicokinetic analysis of 1,1'-[oxybis(ethyleneoxy)]diethylene (Diethyleneglycol divinyl ether)

 

Diethyleneglycol divinyl ether is liquid at room temperature with a molecular weight of 158.19 g/mol and an absolute density of 0.968 g/cm³ at 20 °C. The substance has a melting point of – 21 °C and a boiling point of 191 °C. A water solubility for Diethylene glycol divinylether of 16 g/L (20 °C) and a log Pow of 0.23 (25 °C) were determined.The vapour pressure was estimated to be 0.3 mbar (20 °C).

 

Absorption:

Based on the low molecular weight, the moderate log Pow and a high water solubility, Diethyleneglycol divinyl ether is likely to be absorbed in the GI tract. As it is a non-ionisable substance, absorption is independent of the pH value which is present in the different GI sections. The vast amount of Diethyleneglycol divinyl ether will be absorbed in the small intestine due to the much larger surface area when compared to stomach.The log Pow between -1 an 4 indicates that it will diffuse well across plasma membranes. In addition, gastro-intestinal absorption of Diethyleneglycol divinyl ether is triggered by passage via passive diffusion through aqueous pores or carriage with the bulk passage of water, which is favoured for small (molecular weight < 200 g/mol), water soluble substances. It is unclear whether an active transport for Diethyleneglycol divinyl ether exists. Overall, extensive gastrointestinal absorption is expected for Diethyleneglycol divinyl ether based on its physicochemical properties. Moreover, numerous systemic effects seen in acute and repeated dose toxicity studies after oral administration demonstrate and support that Diethyleneglycol divinyl ether is well absorbed in the gastrointestinal tract.

As Diethyleneglycol divinyl ether is a liquid with relative high water solubility (16 g/L), a molecular weight well below 500 and a log Pow of 0.23, dermal absorption is likely, but lower than oral absorption as Diethyleneglycol divinyl ether showed only mild effects when tested for acute dermal toxicity.

Diethyleneglycol divinyl ether exhibits a low volatility (vapour pressure of 0.3 hPa) and a high boiling point (> 190 °). Therefore, only a minimal amount of the substance is available for inhalation. However, when vapour or particles reach the alveolar region of the lung they are assumed to be absorbed directly across the respiratory tract epithelium of the alveolar and capillary membranes due to the log Pow > 0.

 

Distribution and metabolism:

Based on the physicochemical properties (molecular weight: 158.19 g/mol, log Pow: 0.23, water solubility: 16 g/L), Diethyleneglycol divinyl ether is likely to be widely distributed systemically throughout the extracellular compartments of the body after absorption.

Particularly due to the high water solubility and the moderate log Pow value below 3, a long biological half-life in tissues can not be expected. Thus, Diethyleneglycol divinyl ether has no bioaccumulation potential.

The metabolism is determined by physicochemical factors like electronic and steric effects within the molecule and/or by the presence of functional groups. Phase II conjugation reactions like glucuronidation or sulfatation might occur subsequent to Phase I reaction,e.g.after introduction of a OH-group via Cytochrome P450 mediated oxidation. Generally, metabolism will render the molecule more polar and harmless, leading to faster excretion. No conversion into a metabolite that is more toxic than the partent is expected as no increases in toxicity where noted in the presence of metabolic activation during the in vitro tests. Therefore, a clear indication is given that the formation of reactive metabolites is unlikely.

 

Excretion:

The relatively high water solubility and the low molecular weight (< 200) indicate that renal excretion is the most relevant route of systemically available Diethyleneglycol divinyl ether.