PVC & Added Chemisty – What You Need To Know

Phthalates

Phthalates are a family of synthetic chemicals with diverse applications in a variety of consumer products.

Their primary use is as a plasticiser in polymeric and rubber materials.

The most important use of PEs (phthalates)- more than 90% of European production – is as plasticisers for polyvinyl chloride (PVC) which they turn into a material which is soft, flexible, resilient and easier to handle.

As PEs are so widely used, they have been subjected to extensive testing to determine their impact on health and the environment. We are still learning about how phthalates affect us, it is unclear because most studies have been carried out on rodents.  However, many phthalates that have been proven to have carcinogenic effects in rodents have been banned from use in toys.

“Annex XVII of the REACH Regulation states that DBP, BBP and DEHP may not be used in any toys and childcare articles and that DINP, DIDP and DNOP may not be used in toys that can be placed in the mouth.” (rsc.org)

For the past 5 years, we at Chieftain Fabrics have completely eliminated DINP from our formulation.

At the time, DINP, (the most commonly used plasticiser in PVC manufacturing) was on the Subjects of Very High Concern list produced by the EU in conjunction with REACH (Regulation, Evaluation and Authorisation of Restricted Chemicals). It has since been removed from this list, however,  and is now only banned in the manufacture of children’s toys which may be placed in little mouths.

This is why we thought it was a good idea to remove it from our recipe. We replaced it with a non-phthalic plasticiser which is an environmentally safe alternative; DOTP. This is a more difficult product to use and it took some time for our production lines to adapt. We think it was worth  the effort, especially as it means our products are perfectly suitable for use in child-centric environments as well as demanding sectors such as transport, education and healthcare.

Flame Retardants

Broadly speaking, flame retardants can be divided in two groups, (1) inorganic or mineral flame retardants and (2) halogenated compounds.

Bromine, chlorine, fluorine and iodine, are the elements in the chemical group known as halogens.  Halogenated flame retardants act directly on the flame, the core of the fire. They are said to act “in the vapour phase”, meaning that they actually interfere with the chemistry of the flame. Chlorine (chlorinated) and bromine (brominated) are both used in this role, but brominated retardants have been the most effective

While the performance of halogenated flame retardance is excellent, many of these chemicals are associated with health and environmental problems.

Companies looking for less toxic products, select safer (inorganic) chemicals.

These mineral flame retardants are non-toxic and work by decomposing endothermically.  This means that at a certain temperature, the compounds fall apart thereby absorbing heat and releasing water vapor.

The oxides that are formed results in a protective layer that provides a smoke suppressing effect.

Any conscientious PVC manufacturer will ensure that they use an inorganic flame retardant in their products.

 

DMF

Dimethylformamide (DMF) is an organic compound that is used as a solvent for many products, including lacquers, pigments and dyes. Known as a volatile organic compound (VOC), DMF can endanger both humans and wildlife, but the threat is regarded as minimal because it does not occur in nature and isn’t encountered by humans outside of occupational settings.

Dimethylformamide is not stable when strong acids or bases are around it, and it hydrolyses back into its original state of dimethylamine and formic acid. According to the Material Safety Data Sheet (MSDS), dimethylformamide is hazardous to health, flammable, reacts to skin on contact and poses a minimal threat of reacting with other chemicals.

 

DMF is on the REACH list and is considered to be a Substance of Very High Concern (SVHC) according to EU regulations.  DMF is principally used as a solvent for lacquers and also in the production of polyurethane.

Once again, it is the responsibility of the manufacturer to ensure that DMF is not included in the formulation of any PVC or PU. It is possible to use lacquers which are based on water and have similar performance characteristics to those based on DMF. These water based lacquers are obviously much kinder to the environment.

 

All PVC manufacturers and suppliers should know what goes into their product. If they are sure that only the best ingredients go into their formulation, they should be letting everyone in the industry know. Not only does this provide a competitive edge, it also demonstrates that a manufacturer takes their responsibilities to the planet seriously and means their green credentials are not to be sniffed at.

 

 

 

Sources:

 

https://www.echa.europa.eu/substance-information/-/substanceinfo/100.000.617

https://pubs.rsc.org/

http://www.greenspec.co.uk/building-design/halogenated-flame-retardants-environment-health/

Molecular, Clinical and Environmental Toxicology, Vol.3  Environmental Toxicology. Editor Andreas Luch