Neodecanoic acid, ethenyl ester

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Neodecanoic acid ethenyl ester is used exclusively in polymerization as a monomer to make the resulting products more hydrolytically and UV-stable. It is not meant to be used as an unreacted substance in any application. The primary uses include vinyl acetate latex polymers where the principal application is paints and coatings (65%), and adhesives i.e. re-dispersible powders (35%).

Four potential sources of environmental exposure have been identified: (1) Production; (2) Processing (monomer polymerization); (3) Formulation of the polymer into a coating; and, (4) Use by consumers and professional users. Production of neodecanoic acid ethenyl ester (or vinyl neodecanoate) takes place at one site in the Netherlands, and is performed in a continuous closed system as a “dry” process for 365 days/year. Releases from production are expected to be minimal. The total global production volume ranges from 46,000 to 230,000 tonnes/yr. Although it appears to be a very stable monomer that is not degraded, at least to a significant extent, by crude liver homogenates of rats in vitro. As stated earlier, the tertiary (neo-) carbon bonding and alkyl chain structure confers a high degree of stability to the molecule, thus it is expected to be strongly resistant to UV light and hydrolytic degradation.

The circumstances of manufacture and use of neodecanoic acid ethenyl ester allow for a continuous control of human and environmental exposure, which are done in closed systems and under strict norms of safety. Occupational, consumer, and even environmental exposure are anticipated to be low, if not negligible. Despite the high toxicity seen in aquatic testing, exposure to the environment is anticipated to be low. In the event of an accidental spill there are mitigation plans in place to minimize exposure and potential hazards.

The acute toxicity tests indicate low toxicity by inhalation, dermal, and oral routes of exposure to rodentsWith regards to irritation in animals, there is evidence of limited (minimal to non-irritating) potential to eyes and skin. Repeated dosing of neodecanoic acid ethenyl ester has shown a low degree of toxicity in rats by inhalation (0.25, 0.5 and 1.0 g/m3 for 6hr/day, 5d/wk, 13 weeks) or oral exposure (100, 250, 1000 mg/kg/d, for 28

Neodecanoic acid ethenyl ester is a commercial mixture of isomers used mainly in the synthesis of polymers to make them more hydrolytically and UV-stable. It is a light viscous liquid, moderately volatile (Henry’s Law Constant 1295.3 Pa.m3/mol (1.3 x 10-2 atm.m3/mol), measured boiling point 212C and vapour pressure 0.386 hPa at 25 C), of low water solubility (5.9 mg/L, measured), and with a moderate affinity towards organic matter While the measured octanol-water partition coefficient (Log Kow or Log P) is 4.9, the bioaccumulation potential from a fish study in which the substance was dosed via the feed indicates that the compound is rapidly eliminated (95% clearance in 14 days depuration, biomagnification factor 0.09).

When modelling for its environmental distribution (Mackay Fugacity Level III) with equal release to air, water and soil, it is predicted that the bulk transport should be to soil and sediment compartments (~78 and 14%, respectively), with very little to air and water (0.5 and 7.6%).

Neodecanoic acid ethenyl ester has been tested for its acute toxicity to fish, invertebrates and algae. No chronic studies have been conducted. Aquatic toxicity testing has been problematic due to its low water solubility and its likely adherence to glassware. The substance is acutely toxic to aquatic organisms: the lowest GLP results are fish LC50 0.84 mg/L, invertebrates (marine copepod) EC50 0.3 mg/L, and algae EbC50 3.4 mg/L and ErC50 > 4.8 mg/L. As indicated above this chemical exhibited a low biomagnification factor, but according to OECD GHS criteria by its derived BCF would be considered to bioconcentrate (=bioaccumulate) since the derived BCF >500.

Human Health: The chemical is a low priority for further work due to its low hazard profile. Environment: The chemical is a candidate for further work. The chemical possesses properties indicating a hazard for the environment (acute toxicity to fish and aquatic invertebrates). Member countries are invited to perform an exposure assessment for the environment and if necessary a risk assessment.