ISI-Marked Toughened Glass: What IS 2553 Means for Partitions, Showers and Railings

In India, toughened and laminated safety glass for buildings must conform to IS 2553 (Part 1):2018 and carry the BIS Standard Mark (the ISI mark) under a licence from the Bureau of Indian Standards. This has been compulsory since 16 September 2020, when the Safety Glass (Quality Control) Order, 2020 came into force. If you are buying a glass partition, a shower enclosure, a shopfront or a glass railing, the pane that arrives on site should carry that mark.

This guide is for the person who signs off the work: a facility manager, a fit-out lead, an architect or an RWA committee. It covers what the standard and the order say, how to check a pane, and what to put in a specification so every vendor quotes the same glass.

What is IS 2553 (Part 1)?

IS 2553 (Part 1):2018, *Safety Glass – Specification, Part 1: Architectural, Building and General Uses*, is the Indian Standard for safety glass used in buildings. It covers toughened glass and laminated glass, and sets the tests a pane must pass, including dimensions and thickness, flatness and, for toughened glass, the fragmentation test that checks it breaks into small blunt pieces rather than long shards. Part 2 of the same standard covers glass for road vehicles and is not relevant to building work.

Is the ISI mark on toughened glass compulsory?

Yes. The Safety Glass (Quality Control) Order, 2020, issued by the Ministry of Commerce and Industry on 14 March 2020 and in force from 16 September 2020, says safety glass covered by IS 2553 (Part 1) must conform to the standard and bear the Standard Mark under a BIS licence. BIS is the certifying and enforcing authority. In January 2025 BIS also issued guidelines for Amendment No. 2 to IS 2553 (Part 1), so the standard itself is still being updated; a processor holding a current licence works to the current version.

How do you check the mark on a pane?

1. Find the mark. It is usually etched or printed in one corner of each toughened pane: the ISI mark, the standard number (IS 2553 Part 1) and a licence number, normally written CM/L- followed by digits. On laminated glass it is on one of the plies.
2. Read the licence number. It identifies the processor that toughened the glass, which is often not the brand of the raw float glass. A pane can be made from a well-known float brand and toughened by a local processor; the licence number tells you who did the toughening.
3. Verify it. The BIS Care app and the BIS online licence search let you look up a licence number and see the holder, the product and whether the licence is in force.
4. Check it before fitting, not after. Once a pane is in a channel or behind a patch fitting the corner may be hidden. Ask for the mark to be shown on site before installation, or on a sample pane at the time of order.

Which glass goes where: toughened, laminated or heat-soaked?

The choice depends on what happens if the pane breaks. Toughened glass breaks into small blunt pieces and the whole pane comes out of its frame. Laminated glass cracks but stays in place, held by its interlayer. IS 16231 (Part 4), the Indian code of practice on glass in buildings and safety related to human impact, deals with where each is appropriate; your architect or structural consultant should apply it to the specific drawing. As a general picture of common practice:

For a deeper look at the two glass types, see laminated vs toughened glass, the glass thickness guide and why toughened glass breaks. For railings, balcony railing height and safety and the glass balcony railing guide cover the detailing.

What should a glass specification say?

If you are comparing quotes for a commercial job, write the glass line the same way for every vendor. Otherwise one quotes 12mm ISI-marked toughened glass with polished edges and another quotes "12mm glass". A complete line reads like this:

• Type and thickness: 12mm clear toughened, or 6.38/8.38/10.38mm laminated, or toughened laminated with the ply thicknesses.
• Standard and mark: conforming to IS 2553 (Part 1), each pane to carry the BIS Standard Mark with a valid licence number.
• Float glass make: the brand of the base float, if you have a preference.
• Edgework: flat polished edges, arrised at minimum; all holes and notches cut before toughening.
• Heat-soak: whether panes for overhead or facade use must be heat-soak tested.
• Hardware: floor spring, patch fittings, hinges or channels by brand and grade, for example SS304.

Our guide to comparing fabrication quotes covers the rest of the quote, line by line.

How does FabWise specify glass?

FabWise's office and shower styles are built on 12mm Saint-Gobain toughened glass with SS304 fittings, as listed on each style page, for example the frameless glass cabin with door at ₹400 per sq ft and the frameless shower partition with door at ₹500 per sq ft. Whoever you hire, us included, ask to see the BIS mark and licence number on the panes before they are fitted. A good vendor will be glad to show it.

Holes, notches and sizes are fixed before the glass is toughened, because toughened glass cannot be cut or drilled afterwards. That is why every job starts with a site visit and our own measurement, see how it works, and why toughened glass takes about 7–10 days to produce after the order.

For commercial work across Delhi NCR, see glass for offices, for builders and developers and for architects and interior designers.