Consumer Reports investigates shattering glassware

September 22, 2011

Most involved Pyrex and Anchor Hocking. Since then Consumer Reports has heard of more than one hundred new incidents.

Though these reports represent only a tiny fraction of the hundreds of millions of pieces of glass bakeware in American kitchens, Consumer Reports is urging the government to investigate.

Barbara Trojanowski says she only uses metal pans after her glass baking dish shattered while it was sitting on top of a heated oven.

"All of a sudden I heard a bang, I felt it hit the back of my leg. The blood was pouring out all over the place," said Trojanowski.

Trojanowski's Achilles tendon was severed. After surgery, she can walk, but doubts she'll be able to golf or dance again.

Consumer Reports has analyzed 145 new reports of glassware shattering after its first investigation last December.

Now it's not just bakeware that's shattering.

"There were eight reports involving glass bowls and seven involving glass measuring cups. Some shattered when hot water was poured into them. And others shattered in the microwave when used to heat foods, even though they're labeled microwave-safe," said Andrea Rock of Consumer Reports.

Pyrex and Anchor Hocking glass bakeware are now made of a type of glass called soda lime that has been heat-strengthened. Decades ago they were made of borosilicate.

"Though it's not clear when the switch occurred, the manufacturers say soda lime is less likely to break when dropped or bumped. And they say it's equally resistant to temperature changes," said Rock.

Consumer Reports laboratory tests compared the two types of glass bakeware.

New pans were subjected to extreme heat then put on a wet granite countertop, conditions likely to cause breakage and contrary to the manufacturer's instructions.

Ten out of ten times the soda lime bakeware broke but the borosilicate dishes did not break, though most did after baking at slightly higher temperatures.

"When using glass pans, it's extremely important to follow safety precautions," said Rock.

Among the most important, never place dishes on burners or under broilers and be sure to place hot glassware on dry potholders.

Simply use metal pans in the oven, as Trojanowski now does.

Trojanowski is suing Anchor Hocking, which made the glassware she used. The company says it has been advised not to discuss legal matters.

Both Anchor Hocking and the American manufacturer of Pyrex, World Kitchen, say it's important to follow safety warnings.

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