German outdoor clothing company Jack Wolfskin has said it will ban perfluorooctane sulfonate (PFOA) from its production processes by summer 2014. 

The move, Jack Wolfskin says, comes after tests carried out in Germany on jackets, including some made by the retailer - as well as The North FacePatagonia and Adidas - found the presence of hazardous chemicals, which can pose long-term risks to human health.

The research by environmental campaign group Greenpeace found all but one of the 17 items tested contained perfluorinated and polyfluorinated chemicals (PFCs).

Some PFCs are known to be highly persistent in the environment and can act as hormone disruptors, having adverse impacts on the reproductive system and the immune system.

In a statement released last month, Jack Wolfskin COO Christian Brandt said: "We were not surprised to learn that Greenpeace found PFCs in the jackets they tested, as both models were most likely produced in early 2013."

The retailer has also revealed that half of its apparel collection will already be PFC-free by winter 2014 - two years earlier than originally planned.

"We have distinguished ourselves as the first outdoor company with a concrete roadmap until 2020, outlining our plans to move away from fluorine chemicals, ban harmful substances from the supply chain and ensure transparent manufacture among our suppliers. And we are working purposefully towards this goal," Brandt said.

However, he warned: "As we have no control over the length of time our products are traded, there will still be products available during the interim period which contain PFOA."

"This aside, products are completely safe for our customers and fulfil the strict requirements stipulated in the comprehensive list of harmful chemicals (GreenBook).

"According to Greenpeace, the use of these chemicals is predominately a problem in the countries of production. We are in full agreement with them on this matter and are working hard to address this issue."