I use Pyrex every day, but have not heard of this. Have you?

Be Careful When Cooking With Pyrex Because The Dish Can Explode-Truth!

Summary of the eRumor:
A forwarded email that says Pyrex brand cookware can explode leaving you a mess of food and shattered glass to clean up.

The Truth:
The Pyrex Company has a notices on their web site that says that the Pyrex cookware can break if not used according to the directions. The company includes directions with every new Pyrex product for proper use and care. Directions are also posted on the Pyrex web site: Click for Pyrex site.
According to the manufacturing history section on the website, "PYREX® glass products are made using a tempered soda lime glass composite, as is the vast majority of consumer glass bakeware in the North American marketplace. The Cookware Manufacturers Association considers soda lime an appropriate material for glass bakeware."
World Kitchen, LLC is the company that manufactures many brands of cookware including Pyrex® and CorningWare®. The company has approximately 2,300 employees and operates in the United States, Canada, and Asia-Pacific regions.
updated 10/02/09

A real example of the eRumor as it has appeared on the Internet:
About 5:30 PM there was a loud bang from the oven. Sylvia opened the oven door and the Pyrex dish had shatt ered into a million pieces. The roast beef (our first in many months) was peppered with small shards of very sharp glass. Normally,I am quick to inform Sylvia she did something stupid. However, this time she was nowhere near the stove when it blew. I shoveled the glass and the now mashed potatoes into a bucket with two putty knives. I then sucked the remains with the shop vac. I let everything cool down and then scrubbed the oven with Simple Green and some hot soapy water. It took over an hour to clean up the goo. Upon completion I ran the oven empty to see if the temperature controller was working okay. I suspected the oven got too hot and the dish simply blew. This was not the case however. The oven came up to temperature and cycled normally. We threw a disgusting frozen pizza in the oven and it cooked okay.

What is going on?

I Googled exploding Pyrex dishes and got ten million hits.
Exploding Pyrex is very common.

Here is the story.

A long, long time ago in a country we all know and love was a company named Corning. They made Pryex dishes. The material they used is called borosilicate glass. This stuf f is indestructible. But like everything else, the Bottom Liners had a great idea: sell the technology to another company. The Chinese discovered that using soda lime glass was almost as good as borosilicate glass and a lot cheaper. Today, Wal-Mart is the lar gest distributor of Pryex products. Corning not only sold the technology to a company called World Kitchen, they also sold the rights to the original Pyrex logo. Seamless. The consumer will never know.

Now it seems people are getting hurt using soda lime Pyrex. We were lucky because the dish broke while the oven was closed and the damage was limited to the oven cavity. Others have been less fortunate. Some dishes explode when they are lifted from the heating rack in the oven with devastating results. Some people are heavily scarred. World Kitchen is in denial. They say that the dishes are another brand, not theirs. Contrary to their denials the victims usually have more than one of these dishes and the Pryex logo is clearly visible.

If you buy a Pryex dish beware. The label on the front says oven safe, freezer safe, microwave safe. The instructions on the back tell another story. You cannot move a soda lime Pyrex dish from the freezer to the oven and expect it to survive. The fine print goes on and on about what you are not allowed to do with the Pyrex dish. The fine print has prevented World Kitchen from being sued becaus e they have warned the consumer that their Pyrex dishes are junk from the get go. And they are the same price as the original Corning dishes. What a bunch of losers we all are for buying this crap.

What to do?

If you own borosilicate Pryex dishe s no fear. They have to be more than 25 years old to be sure they are indeed Corning dishes. I am not sure if the old Pryex dishes have anything stamped in them that indicates they are made by Corning. You may continue to use the soda lime dishes for holding stuff. Just do not attempt to roast or microwave with them as the hazard is very clear.

The reason the soda lime dishes let go is that over time they develop micro-cracks. Once a few micro-cracks are present and once some liquid finds its way into the cracks you have the bomb situation. The liquid is like shoving a crowbar in the dish and pulling it apart. Super heated liquids expand rapidly and it is the super heated liquids that force the soda lime glass to shatter into tens of thousands of shards.

Since Corning no longer makes Pyrex and Sylvia proudly holds a large collection of the soda lime Pyrex, we decided that one bomb in the kitchen is enough.

First of all, the story is inconsistent. It first says "Sylvia opened the oven door" and then it says "…but this time Sylvia wasn’t near the oven"…. So, i don’t trust the story. However, without some precautions all dishwares can and do explode. So handle everything with care. And while opening the oven door, stay as far as possible, cause the heat can harm your eyes, and i take out the baked goods at least 30 second after I open the oven door.