Safety glass markings

My understanding is that safety glass is *marked* as such.
How "old" is this requirement? I.e., how can I know for sure if particular (old) glass is tempered or not?
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On Thu, 03 Mar 2016 01:36:56 -0700, Don Y

Identifying safety glass:
All installed safety glass should be clearly marked with the British Standard test reference BS6206, with the letter L for laminated, and T for toughened, together with the company registration number of the supplier. If you want to identify (older) safety glass that may not have been marked at the time there are some tests which will give an indication, but I would stress should not be relied upon as being definite, and these are: Toughened - look at the glass carefully side on, a distortion, not too dissimilar in looks to sheet glass, should be noticeable where the glass has been heated and cooled.
Also with toughed glass the gas marks will be noticeable when looked at through polarised sunglasses NOT ordinary sunglasses). With Laminated, the only real test is an accurate measurement, which should show up a thickness of 6.4mm and not 6mm as with ordinary float glass.
A calliper type measuring device is really not accurate enough for this, and I use a laser measure which is held to the glass, and even on a double glazed sealed unit it can tell me the exact thickness of each pane, the air gap between, and the overall thickness - all by one push on a button! Find out some more interesting stuff about it at: merlinlazer.co.uk
Location of Safety glass in the home:
1972 saw the introduction in the glazing industry of a new 'code of practice' number CP152 which more or less said that in doors use 6mm glass instead of 4mm glass on the basis that is is thicker and therefore harder to break. In fully glazed doors such as patio doors toughened (tempered) glass was recommended, but all too often not used because of the extra cost to the seller, and because firms selling on price had to keep their costs down, people were still having some very nasty accidents.
'Safety' glass is now mandatory in the home since 1992 when Building Regulations part N, covering glazing materials and their locations for all building work was very first introduced. I believe this was also updated in 1995 and the regulations apply to not only new, but also replacement glass. Briefly then, all glass changed since 1992 should have been done so with the use of safety glass in areas most at risk (called critical locations).
This means most doors and all glazing in windows where the glass is within 2ft 7in - or 800mm, of the floor or ground, where particularly toddlers and the elderly are most at risk.
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On 3/3/2016 7:19 AM, snipped-for-privacy@ccanoemail.com wrote:

All *new* glass!

> on, a distortion, not too dissimilar in looks to sheet glass, should

Thanks! I will have a look. Not sure I'd want to rely on that, though (convincing others that, "Yes, this really *is* safety glass, even though it isn't marked as such!")

Our problem lies with construction prior to that. Back East, there were similar regulations dating back to the ~60's. But, it wasn't part of the UBC until later. So, without relying on *markings* on the glass, it's a crap shoot to know what the rules in place were when these were installed (or WHAT was installed!).

As well as within a couple of feet of doorways.
I think I'll play it safe and treat them as just double pane (i.e., trash).
Thanks!
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On Thu, 03 Mar 2016 10:09:43 -0700, Don Y

New and not custom glass. I got a custom made tempered piece for my microwave and it came in unmarked.
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On Thursday, March 3, 2016 at 2:38:27 AM UTC-6, Don Y wrote:

No. 1, as you *should* know, "safety glass" is not the same as "tempered-glass". On vehicles, safety glass is only "required" on the windshield.
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