A buyer can ask a kiln for the standard number, the test report and its papers. These are the rules we read first.
The Bureau of Indian Standards publishes one standard for each type, named in the table above. The 1992 text of IS 1077 sorts bricks into classes from 3.5 to 35 by average compressive strength. Water absorption after 24 hours may not pass 20 percent by weight up to class 12.5, or 15 percent above. Each brick carries a source mark in the frog (the dent in one flat face). BIS's portal lists an IS 1077:2025, so ask for the current edition.
In IS 1077 and IS 12894 the BIS Standard Mark is optional. IS 12894 says its use needs a BIS licence, so show it only if you hold one. BIS's list of products under compulsory certification, as read on 13 November 2026, names no brick, block or masonry unit. So we do not write that a brick "needs" a mark. Lists change, so check before a claim runs.
The fly ash order is often misquoted. The Ministry of Environment, Forest and Climate Change (MoEF&CC) issued S.O. 5481(E) on 31 December 2021 in place of the 1999 notification, and amended it on 30 December 2022 and 1 January 2024. It names bricks and blocks among the uses for power-plant ash. The paragraph the Ministry quotes on compulsory use within 300 km of a plant names roads, flyover embankments, shoreline works and dams, not house walls. The old 1999 line, that every building agency within 300 km must use fly ash products, was replaced, so do not print it as current.
The Environment (Protection) Amendment Rules, 2022 (G.S.R. 143(E), 22 February 2022) cover kilns. The particle limit is 250 mg per normal cubic metre. New kilns need zig-zag technology, a vertical shaft kiln or piped natural gas. Old kilns had to convert within one year if they stand within 10 km of cities that miss air-quality targets, and within two years elsewhere. A pollution board may set its own date. Pet coke, tyres and plastic may not be burnt. A kiln must stand 0.8 km from homes and orchards and 1 km from another kiln. It needs the authorities' approval, including the mining department's, for the soil it digs.
On the page, state facts: the technology, the fuel, the papers you hold. Ask your state board which dates apply to you. This is general guidance, not legal advice.