An ISI mark is the difference between a pipe that lasts 50 years and one that bursts in three. Here's how to read it and verify it.
Every certified plastic pipe in India carries an ISI mark — but most buyers don't know what the mark actually guarantees, or how to spot a fake. This short guide walks you through it.
What the ISI Mark Means
The ISI mark is granted by the Bureau of Indian Standards (BIS) to manufacturers whose products and factories have been audited and certified against a specific Indian Standard. For pipes, the standard differs by product:
PVC pressure pipes: IS 4985.
CPVC pipes and fittings: IS 15778.
PVC SWR pipes: IS 13592.
PVC column pipes: IS 12818.
HDPE pipes: IS 4984.
How to Verify It
1. Look at the printing on the pipe itself — IS number, manufacturer name, batch code and class must be present every metre.
2. The BIS licence number (CM/L-XXXXXXX) printed near the ISI mark can be cross-checked on the BIS Care app or bis.gov.in.
3. Ask the dealer for the BIS licence certificate copy.
Why Unbranded Pipes Are Risky
Uncertified pipes often use re-processed scrap material, run thinner walls than the standard, and skip stabilisers — meaning they crack within a few summers of Indian sun. The cost saving at purchase is dwarfed by the repair cost when an in-wall pipe fails.
Frequently Asked Questions
What is the ISI mark on PVC pipes?
The ISI mark is a certification from the Bureau of Indian Standards (BIS) confirming the pipe meets the relevant Indian Standard for material, wall thickness, pressure rating and quality control.
How do I check if a pipe is ISI certified?
Look for the ISI mark and CM/L licence number printed on the pipe, then verify the licence number on the BIS Care app or at bis.gov.in.
Are all Jindal pipes ISI certified?
Yes. Every Jindal PVC, CPVC, UPVC, SWR, column, casing and HDPE pipe is manufactured under valid BIS licence and carries the ISI mark.
Reviewed by
Sahil Jindal
Managing Director, Jindal Composite Tubes Pvt Ltd
3rd-generation pipe manufacturer with 25+ years of hands-on experience in PVC, CPVC and UPVC pipe engineering, ISI/BIS compliance and India-wide plumbing distribution.