Bisphenols

Hazards

Compounds in this group may act as endocrine disruptors and are suspected of damaging fertility or the unborn child. They are also suspected of causing genetic defects and may cause cancer. They may be very toxic to aquatic life, with both short- and long-lasting effects.

 

Function and use

The most widespread function associated with bisphenols is as a monomer in the formation of polycarbonate and epoxy polymers. Bisphenol A (BPA) is produced in large quantities primarily for these functions.

Depending on the other functionalities of the chemical structure, this group of compounds can function as flame retardants, UV stabilisers, pH indicators or as a developer in thermal printing.

 

Areas of application

Bisphenol A is primarily used for the manufacture of polycarbonate and epoxy plastics. Polycarbonate plastic is used in products such as CDs, DVDs and dental materials. It can also be used in plastic bottles and lunch boxes.

Epoxy plastic can be used in electronics, building materials, in adhesives as an internal protective coating in canned food products and soda bottles, and in the renovation of water and waste pipes.

Bisphenol A is also present in thermal paper, which is used for receipts and tickets. Tetrabromobisphenol A (TBBPA) is a brominated flame retardant used in electronic equipment and thermoplastics.

 

Restrictions

In the EU, Bisphenol A is restricted in food contact materials mainly by migration limits. It is also forbidden in baby bottles and food contact material intended for children under 3 years of age and is regulated by migration limits in toys intended for small children. Its use in food contact material is prohibited in France. BPA is further banned in thermal printing paper, most often used as cash receipts.

BPA is listed on the REACH Candidate List. Other bisphenols, including TBBPA, are on the CoRAP list.

 

Alternatives

Alternative approaches

Available alternatives for coating are the use of non-aromatic diols such as isorbide or polyester coatings such as PolyKoats thermoplastic. Examples of alternatives for thermal paper are Appvion’s Alpha® Free, which is based on vitamin C, and Ökobon® thermal paper.

 

Alternative substances

There is research and development ongoing around the use of bisphenol and there are existing commercial alternative compounds on the market from companies such as Arkema, Evonik, Hempel, Croda and others. Production of valPure V70 involves a type of bisphenol that is different from BPA and is shown not to interfere with endocrine systems. This bisphenol is also eliminated at the end of the manufacturing process.

There are several alternatives to brominated flame retardants (see information on halogenated compounds).