Epoxidized soybean oil (ESBO) is a collection of

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

s obtained from the

epoxidation In organic chemistry, an epoxide is a cyclic ether, where the ether forms a three-atom ring: two atoms of carbon and one atom of oxygen. This triangular structure has substantial ring strain, making epoxides highly reactive, more so than other ...

soybean oil Soybean oil (British English: soyabean oil) is a vegetable oil extracted from soybean (''Glycine max'') legumes. It is one of the most widely consumed cooking oils and the second most consumed vegetable oil. As a drying oil, processed soybean oil ...

. It is used as a

plasticizer A plasticizer ( UK: plasticiser) is a substance that is added to a material to make it softer and more flexible, to increase its plasticity, to decrease its viscosity, and/or to decrease friction during its handling in manufacture. Plasticizer ...

and stabilizer in

polyvinyl chloride Polyvinyl chloride (alternatively: poly(vinyl chloride), colloquial: vinyl or polyvinyl; abbreviated: PVC) is the world's third-most widely produced synthetic polymer of plastic (after polyethylene and polypropylene). About 40 million tons of ...

(PVC)

plastic Plastics are a wide range of synthetic polymers, synthetic or Semisynthesis, semisynthetic materials composed primarily of Polymer, polymers. Their defining characteristic, Plasticity (physics), plasticity, allows them to be Injection moulding ...

s. ESBO is a yellowish viscous liquid.

Manufacturing process

ESBO is manufactured from soybean oil through the process of

. Polyunsaturated vegetable oils are widely used as precursors to epoxidized oil products because they have high numbers of carbon-carbon double bonds available for epoxidation. The

epoxide In organic chemistry, an epoxide is a cyclic ether, where the ether forms a three-atom ring: two atoms of carbon and one atom of oxygen. This triangular structure has substantial ring strain, making epoxides highly reactive, more so than other ...

group is more reactive than double bond, thus providing a more energetically favorable site for reaction and making the oil a good hydrochloric acid scavenger and plasticizer. Usually a

peroxide In chemistry, peroxides are a group of Chemical compound, compounds with the structure , where the R's represent a radical (a portion of a complete molecule; not necessarily a free radical) and O's are single oxygen atoms. Oxygen atoms are joined ...

or a

peracid A peroxy acid (often spelled as one word, peroxyacid, and sometimes called peracid) is an acid which contains an acidic group. The two main classes are those derived from conventional mineral acids, especially sulfuric acid, and the peroxy deri ...

is used to add an atom of oxygen and convert the -C=C- bond to an epoxide group.

Uses

Food products that are stored in

glass Glass is an amorphous (non-crystalline solid, non-crystalline) solid. Because it is often transparency and translucency, transparent and chemically inert, glass has found widespread practical, technological, and decorative use in window pane ...

jars are usually sealed with

gasket Some seals and gaskets A gasket is a mechanical seal which fills the space between two or more mating surfaces, generally to prevent leakage from or into the joined objects while under compression. It is a deformable material that is used to c ...

s made from PVC. ESBO is one of the additives in the PVC gasket. It serves as a plasticizer and a scavenger for hydrochloric acid released when the PVC degrades thermally, e.g. when the gasket is applied to the lid and food product undergoes

sterilization Sterilization may refer to: * Sterilization (microbiology), killing or inactivation of micro-organisms * Soil steam sterilization, a farming technique that sterilizes soil with steam in open fields or greenhouses * Sterilization (medicine) render ...

. ESBO is also used in PVC cling films for wrapping foods and toys.

Safety

Food

A Swiss survey in June 2005 showed that (among many other plasticizers exceeding the legal limits) migration of ESBO into foods reached up to 1,170 mg/kg. Rapid Alert System in Food and Feed (RASFF) had also reported cases of food product rejection in EU for exceeding specific migration limit (SML) under EU Legislation (EC/2002/72).EC.europa.eu RAPID ALERT SYSTEM FOR FOOD AND FEED
/ref> Enforcement authorities took measures to force producers respecting the legal limits.

Legislation

In Europe, plastics in food contact are regulated by Regulation (EU) 10/2011. It establishes a SML for ESBO of 60 mg/kg. However, in the case of PVC gaskets used to seal glass jars containing infant formulae and follow-on formulae as defined by Directive 2006/141/EC or processed cereal-based foods and baby foods for infants and young children as defined by Directive 2006/125/EC, the SML is lowered to 30 mg/kg. This is because babies have higher food consumption per body weight.

Toxicity

The tolerable daily intake (TDI) of ESBO defined by the Scientific Committee on Food (SCF) of the EU is 1 mg/kg body weight. This value is based on a toxicological assessment performed by the

British Industrial Biological Research Association The British Industrial Biological Research Association was a government-run research association in the UK, and is now a private company, that investigates toxicology of commercial products. History The organisation was formed in 1961 by the Depa ...

(BIBRA) in the late 1997. Repeated oral administration had been shown to affect the liver, kidney, testis and uterus of rats.Epoxidised soya bean oil
Bibra-information.co.uk According to the conventional European rules for food packaging materials, the TDI became a basis for the SML of 60 mg/kg.

References

{{Reflist Plasticizers Epoxides