The properties of epoxidized linseed oil (ELO) and epoxidized
soya bean oil (ESBO) are provided below. No data on
epoxidized tall oil (ETP) could be found. These products are
similar in composition and are based on naturally occurring
mixtures of triglycerides, containing variable amounts of
unsaturated fatty acids (e.g., linoleic, oleic, and linolenic
acids).
The epoxidized glycerides are primarily reactive
diluents and find use in coatings of food cans. They are
recommended for PVC homo- and copolymer stabilization
and plasticization for rigid, flexible, extruded, calendered,
and molded compounds. Applications are found in intravenous
tubing, blood bags, food wrap film, cap liners and seals,
meat trays, upholstery, pipe, and construction materials.
These epoxidized oils are made by epoxidizing the unsaturated
bonds of unsaturated carboxylic acid–glycerin esters
(triglycerides) with peracids (peracetic acid or its equivalent,
hydrogen peroxide in acetic acid). Because the molecular
weights of these esters approach 900 before epoxidation and
because the unsaturated esters are diluted with inert palmitates
and stearates, there are sufficient epoxy groups to bind
them into polymers, but too few to constitute much of a
handling hazard even though there may be a di- or triepoxide
content.
In a study conducted to current
testing guidelines, no evidence of carcinogenic response
was observed in rats exposed to dietary concentrations
up to 2.5% ESBO. Older studies also showed a lack of a
carcinogenic effect in orally exposed rats. Other studies using
dermal, intraperitoneal, or unspecified exposure routes were
inadequate or inconclusive regarding the carcinogenic potential
of ESBO .
