# How much does the quality of glassware matter, really?

Discussing about the pros and cons of glassware from different manufacturers for chemistry experiments easily becomes a heated debate. Well, that's how it seems if you read the chemistry related blogs, discussions, questions, etc. over the internet. How much does it really matter what kind or type of glass one is using? How big the differences are across different manufacturers?

It would be nice if the answers also elaborated on the differences between laboratory and home chemistry.

• Great question but it is rather ambiguous, since there are window glasses and glass storage's, glassware for food and appliances and building things as well. Each one of them is made differently to accomodate to different needs. The quality of the glassware, essentially, depends on the use of the glass. I can go on and list different types of applications for glass. Check here for more information. – Asker123 Mar 12 '15 at 20:13
• The question says for chemistry experiments. I suspect that it is a rare chemistry experiment that deals with making windows.. Though, we can restrict the question to educational and research chemistry experiments. – per Mar 13 '15 at 8:25
• The difference that I see between different manufacturers is the thickness of the glassware. From one company, it is about half as thick as it is from another (and about 10 times more fragile). – LDC3 Mar 14 '15 at 17:42
• @per, do you mean the quality of the glass material itself, or the grading of the glassware (e.g., grade A versus grade B volumetric flasks or graduated cylinders)? – hBy2Py Jul 29 '15 at 14:11

In addition to differences in the absorption spectrum, different types of glass are more or less able to deal with temperature or mechanical shocks. But that is less about manufacturer: you'll find different types of glassware from the same manufacturer for different purposes (e.g. Fiolax and Duran are both by Schott).

As @LDC already commented, some glassware is thin walled and more mechanically fragile. OTOH, thick walled glass is more likely to break with a temperature shock. So e.g. for test tubes you have to decide whether you want to have them

• suitable for local heating => thin wall borosilicate glass
• suitable for centrifuge => thick wall borosilicate glass
• cheap => soda glass
• UV transmittant => quartz
• suitable for huge temp shocks => quartz

If this question is about whether your borosilicate glass ware is called Duran or Pyrex (or Jenaer or Ilmabor or Rasotherm) I don't see that much of a difference.

• I am not sure about other brands, but Pyrex made in America is actually soda-lime glass. Anywhere else it should be borosilicate. So, if you get Pyrex and want high quality, buy stuff manufactured outside of America. – ChemBird Jul 6 '16 at 3:14
• @ChemBird You're talking about Pyrex kitchenware. The consumer products portion of Corning was spun off, and Pyrex brand kitchenware is now made by a number of different (non-Corning) companies (with the US one using soda-lime glass). Corning held on to the Pyrex trademark for labware, though, and still uses borosillicate. – R.M. Feb 20 '18 at 19:00

You've likely heard of the common and useful reagent, diazomethane $\ce{CH2N2}$, which methylates carboxylates to their esters without acidic conditions, forms carbenoids and therefore cyclopropanes and other structures. You have almost certainly been advised about that reaction as such compounds give even careful experimentalists pause about the quality of glassware used and the cost-benefit of using it.

New glass of the highest density and engineering is requisite. Even finely scratched, apparently new glass, regardless of temperature tolerance, shock and so on will not only ruin your diazomethane reaction but also potentially rob you of your sight, hearing, several digits, and appendages and can end your life in an instant. A trace of water or even causing a dilute solution to freeze and form crystals can trigger detonation. Consider spilling it..!
Small imperfections in the wrong sort of glass surface may not be visible but can cause detonation [1]. In a closed vessel, violent explosive discharge in all directions have caused many to pay with their lives for the cavalier attitude I hear echoed in the QA about warnings of equipment quality and handling, especially glassware. There are safer variants but a "home" (your term) chemist won't have access to that.

How much does it matter? Does your life matter? Ever run an ozonolysis reaction? Isolating an intermediate molozonide prematurely can cause similar destruction to the careless whether using low or high thickness but inferior quartz or glass or even steel.

A sealed glass tube with a hard cap are unusually thick due to the temperature extremes they were designed to tolerate in dewars and heating vessels. But these extreme uses can have extreme outcomes.

K. Barry Sharpless, Nobel laureate was making his rounds around an MIT lab in 1970, sans eye cover. When a student of his pulled a sealed-tube reaction out of liquid nitrogen to display it, the rapid warming of the contents in ambient air did not leave any time for Prof. Sharpless to evade the barrage of miniscule glass shards that expanded outward from the rapidly warming solution at tremendous force, enough to shatter. He (Sharpless) did not lose his life (he would've otherwise missed his share of the recent Nobel prize for his work in catalytic asymmetric induction. The prize isn't awarded posthumously). Instead, he lost an eye.[2]

Use these chemicals with "home-ware" and cheap glass, in your trailer (I kid you, sort of), with no hood, no blast shield, coat, thick gloves and expect a short life for you and anyone unfortunate enough to be near you.

1) Handbook of Reagents for Organic Synthesis – Reagents, Auxiliaries and Catalysts for C-C Bond Formation, edited by Robert M. Coates and Scott E. Denmark, John Wiley & Sons, Inc., 1999, ISBN 0-471-97924-4

2) How dangerous is chemistry? Nature 441, 560-561(1 June 2006) doi:10.1038/441560a

Obviously it depends what you are doing.

I often use glassware that is kitchen quality and comes from kitchen suppliers because it is way cheaper. You can get perfectly good graduated Pyrex beakers with handles from kitchen suppliers at 1/10th the cost of what it would cost to buy it from Cole-Parmer. This is true of many other everyday items.

On the other hand, I have had bad experience with made-in-china soda glass chemware. Often the items are thinner than normal and tend to break easily. Once I bought a lot of test tubes that were sourced in China and they are very fragile and break easily. Better quality glassware has thicker walls so it is more resistent to breakage.

Another issue is annealing. With borosilicate and other tempered glasses, they need to be annealed to be shock resistant. If you buy from a sketchy supplier the items might not have been annealed properly, which will make them more likely to fracture in use. If you are dealing with hot acid or items like that, it is important to have rugged, shock resistant glass.

Unfortunately, it is hard to tell the differences in quality without a lot of experience. One manufacturer can make good items one year, but then start skimping and process lower quality items the next. Also, note that certain manufacturers are known for certain items and those items will often be much higher quality than their non-specialty stuff which is just there to "round out" their catalog. For example, (to use an analogy from hand tools) Stanley is known for their hammers, so you would not be advised to buy a drill from them. Same principle for glass blowers.

The simple glass is not recomended to use in laboratory IF you are using substances thay may emit Ultra Violet light, because the glass absorbs it and we know that that kind of light has a really high energy. Therefore quartz ( silicon dioxide ) is more suitable. And of course, radioactive elements will need special conditions.

• Quartz also helps if you want to deliver UV light into the glassware (photochemistry). – cbeleites unhappy with SX Mar 14 '15 at 21:41