Regulator gives favourable ruling on chemical coating
tanks or pipe fittings covered with novolac glycidyl ethers (NOGE)
after the EU's food safety regulator ruled that the epoxy coating
is safe as a coating.
EU Commission directive 2002/16/EC governs the use of certain epoxy derivatives, including NOGE, in materials and articles intended to come into contact with foodstuffs. It makes all playersin the supply chain responsible for checking if the product they put on the market is compliant with the safety limits placed on chemical migration into foods.
The directive banned the use of NOGE in materials and articles made of plastics, articles covered by surface coatings or adhesives. However it did not ban the chemical from being usedas a heavy duty coating used on containers and storage tanks having a capacity greater than 10,000 liters and for pipelines connected with them.
At the time of the adoption of the directive information on the toxicological profile and potential exposure to NOGE was not available.
Materials and articles containing 2,2-bis (4-hydroxyphenyl) propane bis (2,3-epoxypropyl) ether (BADGE), bis (hydroxyphenyl) methane bis (2,3-epoxypropyl)ethers (BFDGE) and NOGE were found totransfer significant levels of those substances to foodstuffs, particularly when used as additives. The chemicals were found to represent a potential risk to human health.
Epoxy phenolic novolac resins such as NOGE are used as a starting substance in epoxy resins used for heavy duty coatings.
After the EU directive was passed the use of NOGE and related BFDGE chemicals were phased out from being used as coatings for metal food cans but not from large scale tanks and pipes used by theindustry.
At that time the EU's safety panel concluded that the large volume to surface area ratio of such containers and their repeated use over their long lifetime reduced the migration and their contactwith foodstuffs at ambient temperature in the majority of the applications.
The panel suggested that it was not necessary to set a migration limit for NOGE and BFDGE in such containers.
After the directive came into effect, the European Food Safety Agency (EFSA) was asked to carry out risk assessments on the use of NOGE in such vessels and the pipes going to them.
The request was made after a subsequent opinion on BFDGE, a component of NOGE, found that the chemical could not be regarded as a worst case test compound for evaluating the toxicity of NOGE.
After tests on rodents the EFSA said specific migration from heavy duty coatings showed that it could be used in heavy duty coatings in large vessels, those above 10,000 litres and the pipes aslong as migration is less than or equal to 50 parts per billion in a kilogram (50 ìg/kg).
The EFSA scientific panel concluded that "the use of NOGE as a starting substance in heavy duty epoxy coatings is not of concern from a safety point of view"..
Epoxy phenolic novolac resins are used as starting substance in heavy duty epoxy coatings, with the function of crosslinker and polymeric epoxy binder. In some countries outside the EUit is used as a polymeric additive in PVC (polymer of vinyl chloride) organosol can coatings, functioning as a heat stabiliser and as a hydrogen chloride (HCl) scavenger.
NOGE as an additive in PVC organosols has been phased out in the EU since the end of 2000.
