1,4-bis(2,3-epoxypropoxy)butane

Endpoint summary

Description of key information

Short description of key information on bioaccumulation potential result: In accordance with REACH Regulation (EC) No 1907/2006 Annex VIII section 8.8.1, a toxicokinetics study is not required as assessment of the toxicokinetic behaviour of the substance has been derived from the relevant available information. This assessment is located within this endpoint summary for toxicokinetics, metabolism and distribution.

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Additional information

No studies specifically investigating the toxicokinetic properties of epoxy resins were available; thus, the physicochemical properties of the substance and the results of toxicity studies were used to assess the toxicokinetics of epoxy resins. The low molecular weight (i.e., <500 g/mol), liquid state, moderate log Pow value (i.e., between -1 and 4), and high water solubility (i.e., above 10 g/L) of epoxy resins favour their absorption from the gastrointestinal tract [1, 2, 3]. The absorption of epoxy resins following oral exposure is supported by the systemic toxicity (i.e., mortality) observed in rats and hamsters following acute oral administration of 600 to 8000 mg epoxy resins/kg body weight [4, 5, 6, 7, 8]. Spasms/convulsions were reported in 2 studies in rats acutely exposed to doses of epoxy resins of ≥2000 mg/kg body weight, doses that far exceeded the derived LD50 values [4, 8]. These observations, particularly those of sedation, suggest that the compounds may cross the blood-brain barrier following oral exposure. Alternatively, sedation may be a nonspecific physiological response to high oral doses of the test substances and not be related to direct CNS effects. No signs of potential CNS effects were observed on any day of oral exposure of rats to epoxy resins at doses of up to 400 mg/kg body weight/day for 28 days [9]; however, this finding does not preclude the distribution of epoxy resins to the CNS.

 

Hepatic effects were observed in 1 of the 5 available acute oral toxicity studies, as well as in the available subacute (28-day) oral toxicity study. The observation of hepatic effects in the study in which rats were acutely administered oral doses of up to 2150 mg epoxy resins/kg body weight suggests that epoxy resins may be distributed to the liver following oral exposure [7]; however, hepatic effects, or any other pathological changes, were not observed in any of the other 4 acute oral toxicity studies, despite exposure to higher doses (i.e., up to 8000 mg/kg body weight) of epoxy resins. In addition, increased relative liver weights and serum albumin:globulin ratios (with no corroborating histological changes) were observed in rats following oral administration of 400 mg epoxy resins/kg body weight/day for 28 days [9]. No other statistically significant, compound-related systemic effects were observed. Thus, the available oral toxicity data suggest that epoxy resins are absorbed following oral exposure and distributed to the liver; distribution to the CNS cannot be ascertained with certainty. No other relevant toxicokinetic information can be deduced from the results of the available studies.

 

The liquid state and low vapour pressure [10] of epoxy resins favour their absorption via the skin; however, the high water solubility and negative log Pow value do not favour dermal absorption, since these values indicate that epoxy resins may be too hydrophilic to cross the stratum corneum. In addition, the high surface tension [11] of epoxy resins (i.e., above 10 mN/m) does not favour dermal absorption. Although dermal irritancy or corrosion may enhance dermal absorption by compromising the integrity of the epidermal barrier, no corrosion or systemic effects were observed in either of the acute or repeated-dose dermal toxicity studies available. Thus, considering the physicochemical properties of epoxy resins, and the lack of observed systemic effects following dermal exposure, their absorption via the skin is unlikely.

 

No data regarding inhalation exposure to epoxy resins were available. Although the low vapour pressure and boiling point of epoxy resins indicate that inhalation exposure is unlikely, whether the substance would be absorbed following inhalation exposure cannot be deduced from the available information. In addition, no reproductive or developmental studies were available; therefore, whether epoxy resins would be expected to cross the placental barrier cannot be deduced. Based on the available data and taking into consideration the low molecular weight and log Pow value, and considerable water solubility, epoxy resins are not expected to bioaccumulate.

 

References

 

[1]    Nývltová Z (2010) 1,4-bis (2,3-epoxypropoxy)butane - Identification and quantification of impurities and quantification of main component. Výzkumný ústav organických syntéz a.s., Research Institute for Organic Syntheses Inc., Centre of Ecology Toxicology and Analytics, GLP Test Facility, Rybitví 296, 533 54 Rybitví, Czech Republic, Report no. 1059

 

[2]    Čížek K (2010) 1,4-bis(2,3-epoxypropoxy)butane – Partition Coefficient (n-octanol/water). Výzkumný ústav organických syntéz a.s., Research Institute for Organic Syntheses Inc. , Centre of Ecology, Toxicology and Analytics, Rybitví 296, 533 54 Rybitví, Czech Republic, Report no. 10-99.

 

[3]    Štreit V (2010) 1,4-bis(2,3-epoxypropoxy)butane – Surface Tension. Výzkumný ústav organických syntéz a.s., Research Institute for Organic Syntheses Inc., Centre of Ecology Toxicology and Analytics, GLP Test Facility, Rybitví 296, 533 54 Rybitví, Czech Republic, Report no. 1067.

 

[4]    Ullmann L, Sacher R & Vogel R, 1988, Acute Oral Toxicity Study with Grilonit RV 1806 in Rats. RCC, Research & Consulting Company AG, P.O. Box, CH 4452 Itingen., Report number 217596

 

[5]    Kobel W (1983a) Acute Oral LD50 in the Rat. Ciba-Geigy Ltd./ Switzerland GU2 Toxicology CH-4332 Stein/Switzerland, Report number 831248

 

[6]    Kobel W (1983b) Acute Oral LD50 in the Chinese Hamster. Ciba-Geigy Ltd.,/ Switzerland GU2 Toxicology Sisseln facility CH-4332 Stein/Switzerland, Report number 821602

 

[7]    Bathe R (1972) Acute Oral LD 50 of TK 10352 in the Rat. Ciba-Geigy Limited, Report number Siss 1170

 

[8]    Sarasin G (1981) Report on Acute Oral LD50 in the Rat of TK 10352/D. Ciba-Geigy Limited (Exp. Toxicology Sisseln GU 2.1), Report number 810913

 

[9]    Seidel, S (2010) A 28-Day Oral Gavage Toxicity Study of Butanediol Diglycidylether in Sprague-Dawley Rats. WIL Research Laboratories,,, Study number WIL-749003

 

[10]  Harlan Laboratories Ltd (2010), 1 ,4-Butanediol Diglycidyl Ether" EC Number 219-371-7, CAS Number 2425-79-8: DETERMINATION OF HAZARDOUS PHYSICO-CHEMICAL PROPERTIES, Report no. 0759/0016

 

[11]    Štreit V (2010) 1,4-bis(2,3-epoxypropoxy)butane – Water solubility. Výzkumný ústav organických syntéz, Research Institute for Organic Syntheses Inc., Centre of Ecology, Toxicology and Analytics, GLP Test Facility, Rybitví 296, 533 54 Rybitví, Czech Republic, Report no. 10-195