The CPVC compounds “Durastream” and “Durastream α” supplied by the SEKISUI CHEMICALl Group meet and are certified to strict domestic and international standards. They are superior to other plastic materials in various aspects, such as heat resistance and chemical resistance, and are also attracting attention in terms of safety for the human body and reduction of environmental impact.

Durastream product safety

“Durastream” is a product that offers excellent mechanical strength and heat resistance while maintaining high water quality. It is mainly used in hot/cold water supply pipes and fittings because it is less susceptible to corrosion than metal pipes, preventing the deterioration of water quality, such as red and blue water caused by rust. The safety of “Durastream” is ensured by strict internal quality control and certified by domestic and international certification bodies.

Durastream’s strength in ensuring safe water quality

“Durastream” is NSF certified, which sets strict international standards for drinking water safety. In Japan, it also complies with JIS standards and has numerical proof that it does not leach or permeate harmful chemicals. For example, the leachability of lead is below 0.008 mg/ℓ and that of zinc is below 0.5 mg/ℓ. The leachability figures are close to those of PVDF used in pure water lines.
It also has excellent chemical and corrosion resistance, and because it does not rust like metal pipes, it has a smooth surface that is resistant to scale* and is less prone to bacterial growth than other plastic materials.

*Scale: A substance dissolved in the liquid flowing through the pipes that precipitates and adheres to the inside of the pipes. It is a type of water stain.

On the shift to heat stabilizers that are gentle on the human body

Stabilizers are used in the CPVC moulding process to prevent thermal decomposition. In the past, lead and cadmium, which are restricted substances, have been used, but in recent years tin has become more common. However, as tin is also a heavy metal, its environmental impact is unavoidable. As the impact of plastic products on the environment and human health becomes an issue, there is growing interest in the environmental impact of stabilizers. In the search for a heavy tin-free stabilizer, SEKISUI was the first company in the world to mass-produce “Durastream α” which uses COS (Calcium Organic Systems) as an alternative to tin.

Certified standards

In 2013, SEKISUI’s Durastream has obtaind NSF certification, an international certification for drinking water sanitation equipment, and while few CPVC compound manufacturers have been obtained NSF certification, SEKISUI is contributing to global drinking water sanitation by providing products that meet safety standards.