The company that makes Pyrex in the US has taken the publisher of an article to court over claims that the products are dangerous.
However, Pyrex UK told diyweek.net's sister website HousewaresLive.net today that the UK product, manufactured from a different material, is safe.

According to HousewaresLive.net, Pyrex sold in the UK is licensed and manufactured by Arc International Cookware, and is made of borosilicate glass. This is significantly more resistant to thermal shock than the Pyrex products manufactured by World Kitchen for the US market, which are made of heat-strengthened soda-lime glass.

Reports of the US product shattering are not uncommon, and now World Kitchen is suing The American Ceramic Society in the Federal Court over an article which claims that American-made glass cookware, including Pyrex, is unsafe and can injure consumers. The editor of the ACS's Bulletin and the co-authors of the article are also being sued.

The article claims that World Kitchen's Pyrex can shatter or explode, and says it is "unsafe for typical cooking in consumers' kitchens, poses a significant risk of injury to consumers, and is substantially less resistant to breakage during normal use in consumers' kitchens than foreign-made glass cookware".

World Kitchen argued in court that despite Pyrex having an "exemplary safety record, the defendants launched a sensational, multi-publication campaign of disparagement against American-made glass cookware, including Pyrex glass cookware, alarmingly and falsely claiming that Pyrex glass cookware does not provide an adequate margin of safety for typical kitchen cooking..."

It accused the ACS and co-defendants of "sweeping, alarming and highly disparaging assertions, falsely impugning the safety of the entire American glass cookware industry, including Pyrex glass cookware". The ACS, it said, had done no comparative tests of American-made and foreign-made products to support its claims that American Pyrex was much more likely to break in normal use than its overseas counterparts.

Injuries from Pyrex breakages, it added, represented only a tiny fraction of a percent of the Pyrex cookware used in American kitchens for generations.

World Kitchen also maintained that one of the article's co-authors, defendant Richard Bradt, was "currently engaged as a paid consultant and 'expert' in a pending matter adverse to a maker of American-made, heat-strengthened soda lime glass cookware" that Bradt had disparaged, which ACS had not disclosed.

World Kitchen is seeking a retraction and apology, a corrective press release and the removal of the article from ACS's website.

Meanwhile, Pyrex UK today issued a statement saying that the borosilicate glass used for the UK product has been "confirmed as the most resilient and safest glass for oven baking.

"New tests performed by the Société Française de Céramique confirm the high-performance resistance of oven baking dishes made from borosilicate glass to thermal shock, with results that are considerably better than the current European standard in force (EN 1183)," it said.

In the tests, conducted in June this year, soda-lime glass dishes withstood thermal shocks of an average temperature of 171.5 deg C, whereas borosilicate glass dishes withstood average temperatures of 237.8 deg C. Borosilicate glass was the material originally used by Pyrex when it was invented in 1915.

World Kitchen claims that: "While both soda-lime and borosilicate are appropriate compositions for glass bakeware, heat-strengthened or tempered soda-lime glass is more resistant to impact breakage - the far more likely cause of consumer injury."