A steel service centre in Coimbatore received an MTC from a secondary-market supplier for IS 2062 E350 plates. The MTC looked complete — heat number, chemical analysis, mechanical test values all present. The lab report was attached. The quality manager was about to approve the consignment when he noticed something: the lab report header showed an internal lab name with no accreditation reference. He searched the NABL portal for the laboratory. It wasn't listed.
The material sat in quarantine while the supplier arranged fresh testing at a NABL-accredited external laboratory. The delay was eight working days. Two downstream fabrication orders slipped their delivery commitments.
What NABL Accreditation Means
NABL — the National Accreditation Board for Testing and Calibration Laboratories — operates under the Department for Promotion of Industry and Internal Trade (DPIIT) and is India's signatory to the ILAC mutual recognition arrangement. NABL accreditation means the laboratory has been assessed against ISO/IEC 17025 (the international standard for testing and calibration laboratory competence) and found capable of producing technically valid test results in the specific tests covered by its scope of accreditation.
The accreditation is not blanket. A laboratory is accredited for specific tests on specific materials. A metallurgical lab may hold NABL accreditation for tensile testing of steel to IS 1608 and chemical analysis to IS 228 but not for Charpy impact testing. A certificate showing NABL accreditation does not mean the lab is qualified to conduct every test required under a given IS standard.
For BIS product certification, the tests specified in IS 2062, IS 1786, IS 808, or other applicable standards must be performed by a laboratory whose NABL scope explicitly covers those specific tests on those specific materials.
Why BIS Requires NABL-Accredited Labs
BIS product certification is a third-party conformity assessment. The integrity of the certification depends on the independence and technical competence of the testing. If a mill runs its own in-house tests and self-declares conformance without external validation, the certification loses its third-party character.
BIS requires testing at:
- NABL-accredited laboratories, or
- BIS-recognized laboratories (a category that includes some government and institution-operated labs approved directly by BIS)
An in-house mill laboratory — no matter how well-equipped — is not acceptable for BIS certification testing unless it has obtained NABL accreditation for the specific tests required by the standard.
This is the rule many smaller mills violate, knowingly or otherwise. They produce material, test it in-house, issue an MTC with their own test results, and sell it as IS 2062-compliant. Their material may genuinely meet IS 2062 requirements. But without NABL-accredited testing, the MTC cannot be used to demonstrate BIS certification compliance on government projects or for TPI clearance.
What the Test Report from a NABL Lab Must Include
A test report from a NABL-accredited laboratory that will be used for BIS compliance purposes must show:
- Laboratory name and address as registered with NABL
- NABL certificate number — the unique identifier for the lab's accreditation
- Scope statement or reference to the scope — confirming which tests the lab is accredited for
- Test method reference — the IS method standard used (e.g., IS 1608 for tensile testing of steel, IS 228 for chemical analysis)
- Sample identification — heat number, grade, dimensions, that can be cross-referenced to the MTC
- Test results with units and reference to acceptance limits from the applicable standard
- Date of testing
- Authorized signatory — name, designation, and signature
A test report that lacks the NABL certificate number or does not reference the scope is technically incomplete and will be questioned by TPI inspectors and project QA engineers.
How to Verify a Lab's NABL Accreditation Scope
The NABL online directory (nabl-india.org) allows searching by:
- Laboratory name
- Location (city or state)
- Discipline (mechanical, chemical, metallurgical)
- Accreditation number
Once the lab is located, the scope of accreditation is downloadable as a PDF. Review the scope document to confirm:
- The discipline covers the required tests (e.g., mechanical testing of ferrous metals, chemical testing of steel)
- The specific test methods referenced in the MTC (IS 1608, IS 228, etc.) are within scope
- The scope document shows a current validity date — NABL accreditation must be renewed, and a lab's scope can lapse even while the certificate is visually current
For frequently used labs, this check is worth doing once a year and recording in your approved supplier or approved lab list. For first-time labs, verify scope before accepting any test report.
When In-House Labs Are Involved
Many large integrated steel plants operate in-house testing facilities that have obtained NABL accreditation. This is legitimate. An in-house lab with NABL accreditation for the specific tests required by the applicable IS standard can issue test reports for BIS certification purposes.
The checks are the same as for any other lab: verify the NABL certificate number on the test report, confirm the scope covers the required tests, and confirm accreditation is current.
What is not acceptable: an in-house lab that is ISO 9001-certified or quality-managed but has not obtained NABL accreditation. ISO 9001 is a quality management standard, not a laboratory competence standard. These are not interchangeable.
The Downstream Impact on Distributors
Distributors who receive MTCs from multiple mills are exposed to this risk even when they have no quality engineering function at inward. A practical rule: before accepting an MTC where the test report is from a lab you don't recognise, look up the lab on the NABL portal and check scope. If the lab isn't there, call your supplier and ask for a fresh MTC with testing from a confirmed NABL lab.
The eight-day quarantine in Coimbatore was avoidable. The check that would have prevented it takes five minutes.