2-Propenoic acid, reaction products with pentaerythritol

Endpoint summary

Key value for chemical safety assessment

Bioaccumulation potential:

low bioaccumulation potential

Absorption rate - oral (%):

100

Absorption rate - dermal (%):

100

Absorption rate - inhalation (%):

100

Additional information

The UVCB PETIA is used in conjunction with higher molecular weight acrylates as a diluent / cross-linking agent in inks, coatings (e.g. plastic and wood) and adhesives. The substances react under UV light to form polymers, the final products.

The main REACH-related applications of this substance are in industrial and professional settings. Section 9 details the lifecycle of PETIA and indicates potential exposureroutes. Since the substance is in liquid form, dermal or eye exposure may occur as a result of spills or splashes during transport, process or handling. Because of its low vapour pressure, exposure via inhalation is expected to be minimal under ambient conditions. Spraying or situations where exposure at elevated temperatures/pressure may occur are not covered.

No published data could be found on the toxicokinetics of PETIA. However, as per REACH guidance document R7. C, information on absorption, distribution, metabolisation and excretion may be deduced from the physico-chemical properties, including:

-         Water solubility

-         Partition coefficient

-         Vapour pressure

-         Molecular weight

Given the small molecular weight and the water solubility of the main constituents of PETIA, they are likely to be relatively well absorbed into the organisms afteroral exposure. The adducts, with higher molecular weights, may penetrate less easily. In oral administration studies, toxicity was observed, albeit at high doses, indicating that some exposure took place. Pentaerythritol alone has been shown to be taken up and eliminated rapidly in testing with animals and humans. In dogs, 69% of 14C pentaerythritol administered orally was excreted unchanged in 24 h urine, the rest in feces. A later review identified the kinetics as first order and apparently dose-independent. Feeding studies in humans revealed that about 85% of pentaerythritol fed was eliminated unchanged in urine. Elimination was essentially complete within 30 h. Acrylic acid, ethyl acrylate and other simple esters of acrylic acid have also been shown to be absorbed rapidly from the gastro-intestinal tract.

Based on the criteria summarised in Table R.7.12-3 of guidance document R7. C,dermal absorptionof PETIA is expected to be slowed due to binding to skin of the acrylate group. This is supported by the low toxicity observed in acute dermal testing and in line with observations made for acrylic acid, ethyl acrylate and other simple esters of acrylic acid.

Given their moderate log Kow (below 3) and the indication for oral absorption, systemic uptake of pentaerythritol triacrylate and pentaerythritol tetraacrylate afterinhalationexposure is possible. However, exposure through inhalation route is considered to be negligible due to low vapour pressure as well as the fact that spraying or situations where exposure at elevated temperatures/pressure may occur are not covered.

No specific information could be found on metabolism, but evidence from other types of acrylates suggests that hydrolysis of the ester bond is likely to occur, producing acrylic acid and the corresponding alcohol, which are subsequently metabolised through normal metabolic routes. This hydrolysis is mediated by the ubiquitous tissues and circulating carboxylesterases. Another potential route of metabolism and detoxification may involve conjugation of the vinyl group with the sulfhydryl group of GHS, with excretion as mercapturates.

Therefore, in absence of experimental data, default absorption rates are considered for risk assessment according to the ECHA R.8 guidance.