2

I accidentally let all the water boil off in my standard glass kettle (if it matters, it's a Medelco WK112 OneAll Stovetop Whistling Kettle). It didn't crack, and cleaned up fine.

But might there be a lingering chemical change that's left the glass unsafe? (E.g., is there anything it might leach into the water I'll be boiling day after day?)

As per the suggestion of @moscafj, I asked the manufacturer, which replied:

Hi- we do not recommend you to use that kettle any longer if it was boiled out dry as stated in our instructions."

But I am still interested in the question. (I'll get a new kettle to be on the safe side, but not because I "always trust the manufacturer.")

Luciano
  • 4,794
  • 2
  • 20
  • 40
Brendan
  • 53
  • 6
  • Maybe better to contact them directly: https://cafe-brew.com/product/12-cup-glass-stovetop-whistling-tea-kettle-wk112/ Contact info at bottom of page. – moscafj Aug 18 '19 at 20:06
  • 1
    Did it clean up pretty and clear with vinegar, or do you have burnt on mineral deposits? If it looks nice, I'd keep it. If crudded, get a new one. Unleaded glass is unlikely to leach anything nasty into your water. – Wayfaring Stranger Aug 18 '19 at 23:23
  • 4
    I think the risk is not that it will leach anything, but rather that the glass has been subjected to temperatures that might make it brittle and prone to breaking. You really really don't want a kettle full of boiling water collapsing on you when you pick it up. – bob1 Aug 19 '19 at 14:14
  • Interesting, glass is made from fire I wonder if it does any structural damage after it is made – Huangism Aug 19 '19 at 15:24
  • @bob1, excellent point! – Brendan Aug 19 '19 at 17:52
  • @bob1 reads like an answer to me... – Stephie Aug 19 '19 at 20:41
  • @Stephie True. Will add. – bob1 Aug 19 '19 at 21:52

2 Answers2

8

While @Brendan's answer is the correct one as it comes directly from the manufacturer, the risk with glass and other ceramics is not that it will start to leach chemicals into the water, but rather that the glass has been subjected to heat in an abnormal and uneven fashion (the heat is at the bottom and localized, the top will be coolish).

This uneven heating could potentially lead to stresses on the glass that are not visible to the naked eye, but have resulted in microfractures or general weakening of the glass structure. As a result the kettle could potentially collapse/shatter, especially if filled to a high level and boiled. This would result in large volumes of boiling water being released and could result in burns from direct contact with the water and from steam.

bob1
  • 12,979
  • 21
  • 49
3

The manufacturer replied:

"Hi- we do not recommend you to use that kettle any longer if it was boiled out dry as stated in our instructions."

Brendan
  • 53
  • 6