I-TEAM

(WCCO) It may well be the most popular glass bakeware in America. However, some former fans of Pyrex pans are asking if there's a problem with Pyrex. The makers of Pyrex say tests it has provided to the I-TEAM help prove the product is safe. Yet experts the I-TEAM consulted raise questions about that claim.

"It sounded like a shotgun went off. A loud explosion and glass was flying everywhere," said Terry Rhoads.

Rhoads said his pan shattered when he placed it on the counter after removing it from the oven.

"I looked down and that's when I saw about an inch and a half long piece of glass projecting out of the top of my foot," he said.

The I-TEAM asked World Kitchen, the maker of Pyrex, for the results of its own quality assurance and product testing. The company said that's a trade secret. However, to satisfy our requests, the company hired Exponent, a well-respected independent lab to test how Pyrex reacts to what World Kitchen calls "extreme induced thermal shock conditions."

To do it, the lab intentionally violated the instructions that come with the pans.

Those instructions say: Avoid severe temperature changes. Do not add liquid to a hot dish or place dish on a cold or wet surface. Do not use a scratched dish.

Exponent removed seven pans from a 450-degree oven then placed them on a wet towel to induce shock. Three pans did not break, even after water was poured on them.

The four remaining pans had been scratched with a sanding disk prior to heating. Two of those pans fractured when placed on the wet towel. However, the lab says the "velocity and energy were very low" and the farthest a piece of glass traveled was "about one foot."

World Kitchen said the test shows that, "The damage from the forced breakage was not sufficient to cause injury."

Rhoads said his experience was a lot different.

"The velocity was high enough to embed that piece in my foot," he said.

The I-TEAM asked glass experts with doctorate degrees in Material Science, who specialize in glass, to review the Exponent report.

"I think there's some flaws in their testing procedure. First of all, they tested very few specimens. Secondly, they tested empty Pyrex dishes," said Steve Freiman, Ph.D., former Chief of the Ceramics Division at the National Institute of Standards and Technology.

Freiman said the pans should have had something in them because, "It keeps the heat inside and allows the outside to cool and that's what generates the stresses that cause the fracture problem in the first place."

He also said another flaw was scratching the dishes.

"There's not very much strain energy, and the shards don't get propelled very far," said University of Alabama Professor Richard C. Bradt.

As for placing the hot dish on a wet cloth Bradt said, "The soft wet cloth will absorb the energy from the fracture process and then it cannot go in to propelling the shards across the room."

The I-TEAM presented World Kitchen with these experts' criticisms.

In a letter, the company said, "Changing these details would not result in glass fragments being projected much differently."

"One test is worth a thousand expert opinions," said Professor Sheldon Mostovoy, Ph.D. of the Illinois Institute of Technology.

Mostovoy wanted to conduct his own experiment before commenting on Exponent's report. He followed Exponent's example by testing how Pyrex pans reacted when subjected to extreme misuse.

Mostovoy took eight Pyrex pans and put them in a 450-degree oven.

He severely scratched one pan with a glass cutter before heating it to demonstrate how that can lower its energy -- then placed it on wet metal surface.

"The part just fell off. It didn't get thrown at all," Mostovoy said.

All of Mostovoy's dishes were placed on a hard surface instead of a cloth. Two unscratched dishes placed on a dry metal surface did not fracture. Two others placed on a wet metal surface did break, but with little force.

Then he tested unscratched dishes filled with sand to simulate food left too long in the oven -- something you should avoid.

Two pans fractured, sending glass about three feet.

When a third Pyrex pan was placed on wet granite Mostovoy said "it exploded".

"And it threw a piece I'd say somewhere on the order of six to eight feet away," he said.

According to Mostovoy, Pyrex is safe. However, because it's made of tempered glass, "It requires a great deal of care on the part of a homemaker to be sure that they follow the instructions to the letter," he said.

He also said Pyrex instructions are confusing. For example, some say "use dry potholders" -- but for what?

Mostovoy said the instructions don't adequately warn about the dangers of putting a hot pan on anything but a dry, soft surface -- like a potholder.

"I believe they should have it in big letters," he said.

World Kitchen told the I-TEAM that Mostovoy's test "does not accurately demonstrate or depict the actual performance of Pyrex glass bakeware used in American kitchens."

The company pointed out the 66 complaints the Consumer Product Safety Commission forwarded to the I-TEAM is very limited compared to the 369 million pieces of Pyrex sold since 1998.

The company said even those few complaints are unsubstantiated, and that the overwhelming majority of broken glassware returned for analysis turns out either not to be Pyrex or to have been subjected to abuse causing the breakage. And national data for 2005 and 2006 collected by the CPSC shows no emergency room reports of injuries caused by shattered Pyrex.

The company said that and the Exponent test "plainly confirms ... that Pyrex glass bakeware does not present a safety risk."

"I would have to disagree that it's not a safety risk," said Rhoads.

World Kitchen said Pyrex comes with "robust and specific warnings against misuse that could cause breakage" and said Rhoads shouldn't have melted butter inside his Pyrex dish because it causes uneven hotspots that could cause failure.

The directions say not to overheat butter in a microwave, but do not mention heating butter in the oven. World Kitchen also said Rhoads shouldn't have placed his dish on a cold surface, a countertop, even though the instructions don't warn that a countertop should be considered a cold surface.

Pyrex has never been recalled by the Consumer Product Safety Commission. A spokesperson for the CPSC said the government agency does not consider Pyrex to be a hazard, and it does not currently have a glass bakeware research project.

If you have had problems with Pyrex and would like to share your story e-mail the I-TEAM by clicking here.

 

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