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ConsumerWatch: Glass Bakeware Put To The Test

SAN FRANCISCO (CBS 5) – Glass bakeware is a staple in many kitchens. But according to a Consumer Reports investigation, it may not be as sturdy as you think.

Valerie Biddle of Orangevale has painful memories of the last time she used Pyrex. "I removed my dish, closed the oven, and started to walk towards the counter and Boom! It exploded," she said.

Biddle had been cooking chicken at 350 degrees, and said she had turned on the broiler for about ten minutes to brown the poultry. But Pyrex bakeware carries a warning that it should not be put in the broiler.

"All that I had in my hands was the handles, everything else broke into little tiny, tiny, tiny pieces that just spread out all over," she recalled. Biddle suffered burns and deep cuts to her feet.

Biddle's friend, Carla Thadden, of Citrus Heights, has had her own problems with Pyrex. Months after Biddle's experience, Thadden said her Pyrex shattered while she was baking a tamale pie in a 350 degree oven. "I heard this Boom," Thadden told Consumerwatch. "I opened the oven and to my great surprise there was a molten melted mass just sitting there, and I could see the two handles of the Pyrex were tilted down."

Prompted by stories from consumers such as Valerie and Carla, Consumer Reports conducted a one-year investigation of glass bakeware.

The group reviewed 163 shattering incidents, most of them were complaints that had been filed with the Consumer Product Safety Commission. Those incidents included 42 reports of injuries.

Consumer Reports also did its own bakeware test. It compared American-made Pyrex and Anchor Hocking brand glassware to more expensive European-made Pyrex. The American products are made of tempered soda lime glass while the European glass bake ware is made of a different material called Borosilicate.

Testers put dry sand in the bakeware – which gets hotter than food – and put the glass dishes in an oven for 80 minutes at 450 degrees. Straight from the oven the dishes were then placed on wet granite, something that goes against the glassware's instructions.

In all ten instances, the American made bakeware broke. The European made bakeware stayed intact at 450 degrees, but five out of six pieces shattered when the temperature was increased to 500 degrees.

Pyrex took issue with Consumer Reports tests, saying they "clearly violate the instructions for safe use we provide to consumers."

For decades, glass bakeware sold in the U.S. has come with warnings and instructions, often in small print. Those directions can also be found on the companies websites. But some customers might find them confusing. For example, a Pyrex label says "Avoid extreme temperature changes." But, it also said the bakeware is oven and freezer safe.

Pyrex and Anchor Hocking insist their glassware is safe when used according to directions. Both companies also insist the number of reported problems is miniscule compared to the total number of pieces in use.

Still, Consumer Reports is calling on the Consumer Product Safety Commission to do a thorough review of the glass bakeware now on the market. It is also calling for clearer and more prominent warnings on the products and packaging.

(© 2011 CBS Broadcasting Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)

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