Pyrex Vs. Pyrex: What's the Difference?

It's available in the US under the "Arcuisine" brand.

I would have thought that is a pretty minimal requirement. Where else would you put something you take out of the oven.

I assume anything that can go in the oven can go from oven to table and fridge (but maybe not freezer) to hot oven.

You can't visually tell borosilicate and soda-lime apart easily. There is no difference in color (the green vs blue difference is because of other impurities). There is no significant different in refractive index. The only reliable test you can do at home is density (soda-lime 2.52, whereas borosilicate ~2.23, unit g/cm^3).

I measured my "borosilicate" cookwares and all of them are in the ~2.5 range. Turns out they just false advertise. A couple "made in China" beakers I got on Amazon turned out to be borosilicate though. Take that however you will.

Speaking of "very exothermic" ... decades ago a lab colleague of mine once entirely blew out both (glass) sides of his fume cupboard while attempting to melt "ice" with a heat gun. Of course the "ice" that had formed in his flask during the previous reaction turned out not to be ice. The flask itself was later found in lots of very very tiny pieces.

It was the loudest bang I've ever heard, happily he sustained only very minor injuries, with hindsight a minor miracle.

It's a non destructive test. Quote from the video (with funny youtube transcription spelling errors):

"Without getting too technical, the gist is if you put the mineral oil in a vessel made of boroilic and then dip another glass made of boroilicate into it, that glass will seem to disappear while others will not. So I filled a vintage what I think is made of borosilicate Pyrex vessel with mineral oil. Then it dipped in a vintage what I think is made of boro silicut loaf pan and it seemed to disappear right before my eyes. Eureka I thought the experiment works well until I dipped a new Pyrex piece lowercase that I know is not made of borocyic and it disappeared too. Once again, another spokesman at the Cording Museum of Glass that I reached out to said that even the mineral test isn't a sure thing. According to Brady Spalling, he says in order for glass to quote unquote disappear in oil, the glass being submerged must have a similar refractory index, which allows light to pass through both without significantly bending. Mineral oil and borosyic do have similar refractory indexes. So what you've heard is correct. This method is often used to quickly ascertain whether a glass object is borosyicate. However, variability of glass recipes makes it difficult to rely solely upon this method. In short, it may work and it may not."

The article is atrocious.

Some marketing geniuses somewhere concluded that consumers wouldn't notice, and created the line of products that carry the confusing "pyrex" branding but aren't borosilicate based but just thicker or something.

And now they have to have this page to explain the differences.

Not being able to put it under a broiler is a huge disadvantage for nicely finishing dishes like a lasagna.

people say that, but from side by side comparisons of breaking both kinds, it really didn't seem to make a difference.

Its not like car window "glass" that just pebbles.

I think my oven might cycle the bottom element even when pre-heating, possibly to prevent this.

- Company is fully acquired as-is, nothing changes to the product.

- Business division is spun off as-is, nothing changes to the product.

- Company closes current factory, outsources production as-is to another factory in a different country, nothing changes to the product.

- Company makes minor changes to recipe, nothing substantial changes.

- Company uses different recipe in current factory using current tooling, product is substantially different.

- Same factory is used, production line is completely retooled, product is essentially unrelated.

- Original factory is closed, original company now buys imitation product from a 3rd party factory and still uses the original trademark.

- Trademark is sold, slapped on completely unrelated product.

Clearly it isn't as simple as bait-and-switch. There are plenty of scenarios where a lot can change while the product stays the same, and there are a plenty of scenarios where almost nothing changes and the product is completely different.

It gets even murkier when you look at product lines instead of individual products: at what point do you revoke the trademark when they sloowly switch to the cheaper recipe as part of the regular replacement cycle, with all new products only using the budget option and all the legacy premium products getting retired? And how is it going to work for anything more complicated than glassware - where the quality difference isn't a plain "borosilicate glass or not"?

I would like to live in a world where deceptive trade practices did not exist.

Imagine selling a "full-self driving auto-pilot hands-free car!" And then arguing all the letters are lower case in the brand name so all those dead drivers should have known better and should have bought the capital F version.