Interesting to hear people’s experiences, and to see how much interest my original post has prompted. My dish was pyrex, not PYREX (for what it’s worth).
Thanks V8Snail for the video link. My dish exploded exactly the same way, with large, hot sharp pieces as well as dust like shards (for others interested, it’s a 9 min video but you can just view from 2.14 if you just want to see the explosion). Obviously they are setting out to cause it to fail, but so many of us were not being negligent and were not prepared for the explosion. Imagine that inside a kitchen!
I’ve checked the instructions that come with the dish when I last went to the supermarket, and the warning is definitely not clear. It’s fine print, with no warning icon. I also believe it’s confusing for people to have both the warning to avoid extreme temperature changes, but to also have the selling point that it can go from freezer to oven.
As someone who does read fine print (I know most people don’t), and was still caught by surprise, I do think pyrex should have clearer warnings. Given the injuries these explosions can cause, and how common this seems to be, is this something Choice can raise with pyrex?
It appears it depends which factory produces the glass. If the Pyrex product is made in France, it will be borosilicate glass (example of one product - other glass products from the same factory are also borosilicate glass).
Looking at the Corelle Australia website, some glass products sold through Corelle Australia are made in the US. US Pyrex products are made using tempered Pyrex® glass (this is an example - note, link uses a US proxy server as it is otherwise blocked from Australian IP addresses).
The message possibly is if one is buying glass Pyrex in Australia, make sure it is manufactured in France and not the US as the US uses tempered Pyrex® glass, while that produce in France uses borosilicate glass. There are some Pyrex Glass products sold in Australia that are made in France (see Pyrex Australia).
As observed from the video, heating the glass with a blow torch did nothing to upset it, but a single drop of water on that hot glass caused Armageddon.
The heat up from freezer to oven turns much of the tensile stress into compressive stress which puts the glass into its stronger state. A drop of cold water on that hot glass causes immediate contraction in a local spot which is the glass’ weakest mode and a chain reaction is set off. Scratches and nicks can act as a catalyst during any cool down event, whether it’s fast or slow.
Did you catch the bit where they said the camera produced over 19 hours of footage in 5 seconds at that frame rate? Mindblowing. It’s in their best interests to work out the quickest possible way.
I’ll bet the mouse that had a chew on that was slightly perplexed…
Oops.
Is this ‘PYREX’ which is made from borosilicate glass first used by Corning, or is it ‘pyrex’ or ‘Pyrex’ which is something different, and made from normal soda lime glass and just heat treated to toughen it?
The following adds to Wikipedia’s summary on the history of ‘PYREX’ and ‘pyrex’ brands produced by Corning. There have been several changes in brand ownership as well as licensing of the product to other manufacturers. This included the French company Arc.
Corning in the UK produced both borosilicate and tempered soda lime glass ware under the ‘PYREX’ trade mark.
It might soon be irrelevant although US Chapter 11 allows businesses to restructure debts and keep trading with the approval of creditors - nothing quite like it in Australia.
There is a difference between two products. Both owned by the same parent company. PYREX & pyrex. The all uppercase PYREX is made from the original material, and is mainly sold in Europe, Africa and the Middle East. The all lowercase pyrex is made of tempered glass and is sold in US, South America and Asia. The lowercase pyrex does not withstand high temperatures as well as PYREX. So check the label.
Caution if it’s an older product. Wikipedia suggests.
Both trademarks, PYREX (all uppercase) and pyrex (all lowercase, introduced in 1975[16]), were used interchangeably in the marketing of kitchenware products made of both borosilicate and soda lime glass,[17] in addition to related accessories, for several decades.
IE, Historically Corning (looking to older wares) produced branded Pyrex products in the UK using both types of glass, both using the same original uppercase trade mark.
I’ve just come across this video from Anne Reardon warning us about the fact that Pyrex is no longer made of borosilicate glass and the dangers that that presents. I hope Choice will do an article on it.
If manufacturers are going to change the formula of a well-known and trusted product, consumers should be warned.
It’s informative to follow the discussion in the preceding posts. Your post has been moved as it includes similar content covering the two different types of glass used for pyrex products. Enjoyed the video clip.
Note:
Pyrex branded heat resistant glass cookware products have been made for many years using the two different methods/types of glass. Tempered soda-lime glass and borosilicate glass the original 1915 product.
Corning purchased the Macbeth-Evans Glass Company in 1936 and their Charleroi, PA plant was used to produce Pyrex opal ware bowls and bakeware made of tempered soda–lime glass.
The formula has not changed. Knowing which type of glass product one is using is important.
Pyrex products can be wither borosilicate or soda glass depending on the plant the product is manufactured. Pyrex continues to manufacture products from borosilicate glass, both for the domestic kitchen and for other applications (such as for laboratory equipment). The Pyrex EU and UK website still contains information about it’s products and borosilicate glass:
As Pyrex isn’t made in Australia, Pyrex products sold here come from factories around the world meaning that both soda and borosilicate glass products are imported and retailed in Australia. Notwithstanding this, fortunately Pyrex labels provide information on the type of glass the product is made from.
“ortunately Pyrex labels provide information on the type of glass the product is made from.”
If the video’s accurate, there’s nothing on the products to indicate whether it’s borosilicate or soda glass. I have a couple of Pyrex products that don’t indicate which.
There was a period when the PYREX and pyrex were used interchangeablely but buying a new one suggests PYREX will most likely be borosilicate and pyrex soda glass - check the labels. In general PYREX made in France is borosilicate and that made in the USA is soda glass but as companies shift manufacturing around the world and license trademarks willy nilly the only ‘forever constant’ might be that the label has to show the product’s origin even though the physical products do not.
