Some Glass Bakeware Can Spontaneously Shatter

Dec. 7, 2010 — -- The U.S. Consumer Product Safety Commission estimates that nearly 12,000 people were injured by glass bakeware over a decade-long period.

That figure includes injuries from dropping glass and breaking it -- but also from bakeware that shattered on its own.

The glass baking pans are a staple in most kitchens. But some consumers complain that they can spontaneously shatter, sending hot food and glass shards flying.

Consumer Reports spent a year studying the issue and was so concerned that it is now asking the government to investigate.

The complaints started on the Internet.

"The Pyrex bowl … exploded," one person said in a YouTube video.

"It wasn't hot, it wasn't cold, nothing. It was just sitting here and all of a sudden it exploded into a million kajillion pieces," another person said.

Consumer Reports says its tests found that hot glass bakeware can in deed shatter unexpectedly.

"It would break in a forceful way that would actually shoot shards across the room," Don Mays of Consumer Reports told "Good Morning America."

Both major glass bakeware manufacturers -- Pyrex and Anchor Hocking -- say decades ago they switched to a different type of glass that's more environmentally friendly to produce.

"They're using something called soda lime which is a less expensive glass and it's more prone to this sudden fracturing that you're seeing," Mays said.

To compare the two, researchers put European bakeware, which is still make of the old type of glass, in a 400-degree oven, then set it on a damp counter to cool. Nothing happened. But when they did the same experiment with U.S. bakeware made from the new type of glass, the glass shattered every time.

Both companies told "GMA" that Americans use glass bakeware billions of times a year and report problems only a minute fraction – less than one percent – of the time. World Kitchen, maker of Pyrex, said, "Consumers are far more likely to be injured by dropped glass bakeware ..." and that the newer glass is "more resistant to impact breakage." Anchor Hocking said "the vast majority of injuries result from failure to use the product according to instructions."