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Triethylenglycoldivinylether (CAS 765 -12 -8) is a non-volatile (vapour pressure 0.0042 hPa), hydrophilic, water soluble substance (log Kow 1.81 at 25 °C; 30.7 g/l at 25 °C). There is no study concerning absorption, metabolism and excretion of Triethylenglycoldivinylether available.

In general, Triethylenglycoldivinylether is expected to be readily absorbed in the gastrointestinal tract like other vinylethers. Due to the double bond in direct neighborhood to the ether bond, the ether bond is not resistant to enzymatic cleavage in the liver or to hydrolysis in the gastric fluid yielding acetaldehyde from the vinyl group and triethylenglycol. Acetaldehyde is naturally occurring in human metabolism (e.g. metabolism of ethanol) and therefore will be utilized by the human body. Due to the hydrophilic properties there is no bioaccumulation of triethylenglycol to be expected.

Due to the overwhelming amount of literature there are only some key literature given to cover the main aspects of the supposed metabolism.

Sone et al. showed that the vinyl moiety of various aliphatic and aryl vinyl ethers was subjected to microsomal oxidation resulting in the respective epoxides. The authors demonstrated that the oxidation rates by hepatic microsomes from PCB-pretreated rats were significantly higher for various aryl vinyl ethers (range: 8.2 – 14.6 nmol/mg protein/min) than for the two tested aliphatic vinyl ethers (EVE and n-butyl vinyl ether). The oxidation rates were 2.9 nmol/mg protein/min) for EVE, and 5.1 nmol/mg protein/min for n-butyl vinyl ether, respectively. Because of their instability, the epoxides of EVE and n-butyl vinyl ether could not be isolated. Epoxid stability strongly correlates with mutagenicity in strain TA100 with metabolic activation. Because no mutagenicity was discovered in TA 100 with metabolic activation it is concluded that the corresponding epoxide of Triethylenglycoldivinylether is unstable.

Rapid total (100 %) hydrolysis of IBVE into isobutanol and acetaldehyde was shown to occur in simulated gastric fluid (SCF, 1998). Similarly, IBVE hydrolyzed completely within minutes to acetaldehyde and isobutanol when it was incubated with simulated gastric fluid at a pH of 1.5 in another study (BASF AG, 1994). In the latter study, hydrolysis was only approximately 20 % in simulated saliva (pH about 9) at all sampling intervals from 0 through 4 hours after the incubation was started, and approximately 40 % after 1, 2, and 4 hours of incubation with intestinal fluid (pH 7.5). In all simulants, remarkable concentrations of acetaldehyde were found even when no or minor hydrolysis occurred, which, according to the study authors, may be due to the production of acetaldehyde during the derivatization step prior to the analysis by liquid chromatography. The results show that acetaldehyde is a main hydrolysis product of IBVE; no conclusions could however be drawn on the rate of acetaldehyde formation during the ongoing hydrolysis (BASF AG, 1994).

References used:

BASF AG (1994). Hydrolysis tests of vinyl isobutylether. Study report dated 21 December 1994.

SCF (1998). Opinion of the Scientific Committee on Food on an additional list of monomers and additives for food contact materials, adopted the 19 March 1998. Annex II to document XXIV/1269/98, European Commission, Bruxelles.

Sone T, Isobe M, and Takabatake E (1989). Comparative studies on the metabolism and muta­genicity of vinyl ethers. J. Pharmacobio-Dyn. 12, 345-351.