Older double glazed windows in Norway are reckoned to contain 200,000 kilograms of "pure" PCBs in sealant, which can contaminate both frames and glass. The environment ministry estimates a daily release of 50kg as windows are replaced. "Double-glazed windows from the period 1966-75 are one of the biggest sources of PCBs," it continued. "One such window contains between 50 and 100 grams of PCBs, [which] if spread out would be enough to turn a tonne of soil into special waste!"
There has been little compliance with regulations governing the disposal of old windows. "Inadequate collection arrangements have led to the majority falling through the net, often in ordinary rubbish dumps," the ministry said.
A treatment plant for double-glazed windows set up last year by the firm PCB-Sanering uses a process developed in Norway to separate the glass from the contaminated frames. The former is recycled and the latter incinerated, reducing the release of PCBs by 97%, according to the ministry.
The four property agencies, which between them manage 8m square metres of buildings, have signed an agreement with the company to identify and collect all such windows during renovation or demolition work, sending "a strong signal to the commercial sector to take the problem of PCBs seriously".
Although PCBs were banned from all new products in 1980, about 450 tonnes remain in circulation. Another 350 tonnes have been "deposited or dumped".
Please enter your details
Not a subscriber?
Take a free trial now to discover the critical insights and updates our coverage offers subscribers.