The short version.

• PNGRB has not issued a binding national regulation setting a hydrogen-blend target for gas pipelines or city gas distribution (CGD) networks. As of a September 2025 report, the regulator is still drafting blending/transport rules and reportedly needs its own founding Act amended before it can formally regulate the activity.
• The oft-cited "up to 10%" figure traces to a GAIL-authored technical presentation, "Hydrogen Blending with Natural Gas in Pipelines" (February 2022), hosted on PNGRB's own website, which describes a 90:10 by-volume mixture for what it calls a "hydrogen service pipeline." That reads as a technical reference ceiling in an industry engineering slide — not a PNGRB-declared national or pilot target. No PNGRB press release or order stating "10% is our target" was found for this piece.
• The pilots PNGRB has actually approved run below that figure: GAIL/Avantika Gas in Indore started at 1.1–2.0% (commissioned January 2022) and was later raised to 2% in its CNG network and 5% in its PNG network; NTPC and Gujarat Gas at Kawas, Surat started at 5% in January 2023 with a stated plan to scale to 20% in phases; Adani Total Gas's Ahmedabad pilot, covering over 4,000 customers, aims to raise its blend gradually toward 8% or more "depending on regulatory approval."
• The blend ceiling used in each pilot has been set incrementally, case by case, by PESO (Petroleum & Explosives Safety Organisation) as each stage proves out — not from a single published Indian technical study tying a specific percentage to India's pipeline material or vintage. The 10–20% figures that do get cited (the EU's NaturalHy project, the UK's HyDeploy trial reaching 20%) are international reference points GAIL and PNGRB appear to be citing, not an India-validated finding.
• Hydrogen blending sits outside India's National Green Hydrogen Mission as a named funding line — the Mission funds hydrogen production and supply-chain infrastructure broadly, while blending pilots run as separate PNGRB/company initiatives. The one place a specific "10% by [year]" figure does show up officially is Rajasthan's state hydrogen policy, which targets up to 10% blending in the state's own pipelines by 2030 — a state target, not a national PNGRB one, and a plausible source of the number getting attached to PNGRB by association.

Where "up to 10%" actually comes from, and where PNGRB's own rules stand

PNGRB regulates gas transmission and city gas distribution in India, but as of the most recent reporting checked for this piece, it has not finalised a regulation that sets a hydrogen-blending percentage — national, pilot, or otherwise. What exists instead is a layered mix of a technical roadmap exercise, individual pilot-specific approvals granted company by company, and a regulatory framework that is, in the regulator's own recent description of its status, still being drafted. PNGRB, working with the World Bank, commissioned a study titled "Pathways for Transmission of Hydrogen in Natural Gas Pipelines and CGD Networks," covering demand and supply mapping, technical compatibility assessment, and a roadmap running out to 2040; case-study reports tied to that work were filed with PNGRB in June and September 2025. Separately, reporting from late September 2025 states that PNGRB is still working on draft regulations specifically covering hydrogen transport and blending, and that doing so may require amendments to the PNGRB Act and its business rules before the regulator has clear statutory footing to issue binding rules in this area.

Against that backdrop, the specific "up to 10%" figure that gets attached to this story traces to a document GAIL prepared and PNGRB itself hosts: a February 2022 technical presentation, "Hydrogen Blending with Natural Gas in Pipelines," which states that a hydrogen-blended natural gas mixture intended for what it calls a "hydrogen service pipeline" should run at a 90:10 ratio by volume. That is a specific, real number in a real document — but it reads as an engineering reference point inside an industry presentation, not a policy the regulator has adopted as its own target. Nothing found for this piece shows PNGRB issuing a press release, order, or notification that itself declares 10% as a national or pilot ceiling. Readers should treat "PNGRB's 10% target" as an unconfirmed shorthand rather than a settled fact until PNGRB's own drafted regulation, whenever finalised, says otherwise.

PNGRB's World Bank-backed roadmap study and its June/September 2025 case-study filings are drawn from PNGRB's own hosted CSR report PDFs and secondary legal-commentary summaries (Lexology). The September 2025 status of PNGRB's draft hydrogen transport/blending regulations, and the note that PNGRB Act amendments may be required, are from Business Standard's reporting dated 30 September 2025. The GAIL technical presentation and its 90:10 by-volume figure are drawn directly from the PDF as hosted on pngrb.gov.in; this piece treats that document's origin (GAIL-authored, PNGRB-hosted) as material context distinguishing it from a PNGRB-issued policy statement, and found no PNGRB order or release independently adopting 10% as an official target.

The pilots that actually exist, and the percentages each one is really running

Three named, PNGRB-approved pilots account for essentially all of the concrete hydrogen-blending activity in Indian gas networks found for this piece, and their real blend levels are lower — and more varied — than a single round "10%" figure suggests. GAIL, through its joint venture with HPCL, Avantika Gas, in Indore, Madhya Pradesh, ran India's first hydrogen-in-CGD pilot: PESO and PNGRB approved an initial blend of 1.1–2.0% by volume, commissioned in January 2022, later raised to 2% in the CNG network and 5% in the PNG network as the trial progressed. NTPC, together with Gujarat Gas Limited, at Kawas township near Surat, Gujarat, ran what's described as India's first green-hydrogen blending in a piped natural gas distribution network specifically: foundation work began in July 2022, the operation started in January 2023, PNGRB approved an initial 5% by volume, and the stated plan is to scale that up in phases to 20% — the hydrogen itself produced by electrolysis powered by a 1 MW floating solar installation. Adani Total Gas, in Ahmedabad, Gujarat, has a green-hydrogen blending pilot covering more than 4,000 residential and commercial customers, with an expected commissioning date around June 2025 and a stated intention to raise the blend gradually toward 8% or more, contingent on regulatory approval at each step. PNGRB's own filings describe having granted three CGD entities permission for trial blending up to 5% by volume in low-pressure MDPE networks — a description that appears to bundle these three projects together as the regulator's current approved envelope.

Two companies often mentioned in the same breath as hydrogen-blending pioneers don't have a confirmed pilot behind the association. Indraprastha Gas Limited (IGL) in Delhi is discussed publicly as a candidate for hydrogen blending as part of its future multi-energy strategy, but no specific, named, currently-running blending pilot was found for IGL in this research — it should be treated as a stated future interest, not an active project. Avaada appears in coverage of India's hydrogen sector primarily as a green hydrogen production developer; no named pipeline- or CGD-blending pilot specific to Avaada was found, and it should not be assumed to be running one on the strength of its general hydrogen-sector presence.

The Indore pilot's blend percentages, JV structure, and commissioning date are corroborated across a PIB press release, the GAIL/PNGRB technical presentation itself, and trade-press coverage (newsip.in) reporting the later increase to 2%/5%. The Surat pilot's blend levels, dates, floating-solar power source, and 20%-scaling plan are drawn from NTPC's own press release, a PIB release, and a PNGRB filing referencing Gujarat Gas Limited dated 15 March 2024. The Ahmedabad pilot's customer count, expected commissioning window, and blend-target language are from Business Today's November 2023 coverage and Adani Total Gas's own newsroom release. The description of PNGRB having granted three CGD entities trial-blending permission up to 5% in low-pressure MDPE networks is a synthesis drawn from PNGRB's own case-study filings; this piece could not confirm with certainty that the "three entities" line maps one-to-one onto exactly the three named pilots above, though the blend ceilings and timing are consistent with that reading. No named, dated pilot was found for IGL or Avaada specifically, despite both being discussed in broader industry coverage of hydrogen blending in India; that absence is reported as a research finding, not proof no such pilot exists.

What the blend ceiling is actually based on

Blending hydrogen into existing natural gas infrastructure raises a specific, well-documented set of technical concerns: embrittlement of steel pipeline and (for CGD networks specifically) the polymer/MDPE piping widely used in India's lower-pressure distribution lines, compatibility of seals and gaskets not originally designed for hydrogen's smaller molecule and different permeation behaviour, a shift in the gas mixture's calorific value that affects downstream metering and billing accuracy, and end-user appliance compatibility for burners and other equipment calibrated for pure natural gas. None of that is unique to India — it's the same set of concerns cited in international reviews of hydrogen-blending programmes generally.

What is more India-specific, and worth naming directly, is how the safe blend ceiling for each pilot appears to have actually been set: incrementally, and pilot by pilot, by PESO as the safety regulator granting approval at each stage — the Indore trial's own history (1.1% approved first, raised to 2.0% only after that stage proved out) is itself evidence of this case-by-case approach rather than a single percentage derived up front from a comprehensive study. No published India-specific technical study was found for this piece that ties a definitive safe blending percentage to India's particular pipeline material mix and vintage across the network as a whole; the approvals instead look like a conservative, staged process rather than the output of one settled technical finding. The 10–20% figures that do circulate internationally — the EU's NaturalHy research project, the UK's HyDeploy trial which reached a 20% blend in a live network, and a commonly cited 2% cap for cross-border gas flows within the EU — appear to function as reference points that GAIL and PNGRB are citing from elsewhere, rather than numbers independently validated against Indian pipeline conditions.

The technical concerns (embrittlement, seal/gasket compatibility, calorific-value shift, metering accuracy, appliance compatibility) are drawn from a ScienceDirect review article on hydrogen-natural-gas blending and are corroborated in the GAIL/PNGRB technical presentation itself. PESO's role granting incremental approval at the Indore trial, moving from 1.1% to 2.0%, is drawn from PIB and trade-press coverage of that pilot. The characterisation that no comprehensive India-specific safe-blend study was found, and that the approval process instead looks staged and pilot-specific, is this piece's own reading of the available material rather than a claim any single source states in those terms; it should be revisited if a dedicated Indian technical study on this surfaces. The EU NaturalHy project, UK HyDeploy 20% figure, and EU cross-border 2% cap are drawn from a Gas Infrastructure Europe (GIE) position paper on hydrogen blending, cited here as the likely source of the internationally-referenced figures GAIL's presentation echoes, not as evidence those figures were re-derived for Indian conditions.

Where blending sits relative to the National Green Hydrogen Mission

India's National Green Hydrogen Mission, approved in January 2023 with a stated target of 5 million metric tonnes per annum of green hydrogen production by 2030 and an outlay of roughly ₹17,490 crore through 2029-30, funds hydrogen production capacity and supply-chain infrastructure broadly, including pipelines, storage and last-mile distribution components. Pipeline and CGD blending pilots, though, run as separate PNGRB- and company-led initiatives rather than as a named, dedicated line item within the Mission's own published structure — nothing found for this piece shows the Mission allocating funding specifically earmarked for blending trials as distinct from hydrogen production capacity generally.

The one place a specific "10% by a stated year" figure does appear in an official document, rather than an engineering slide, is at the state level: Rajasthan's own green hydrogen policy sets a target of up to 10% green hydrogen blending in the state's natural gas pipelines by 2030. That is a real, named, dated target — but it is Rajasthan's state target for Rajasthan's own pipelines, not a PNGRB national standard, and it's a plausible explanation for how a genuine "10%, 2030" figure circulating in policy discussion gets attached, inaccurately, to PNGRB as the national regulator.

The National Green Hydrogen Mission's approval date, 5 MMTPA 2030 target, and ₹17,490 crore outlay are drawn from the Mission's own government-published policy document (hosted via cdnbbsr.s3waas.gov.in). Rajasthan's state-level 10%-by-2030 pipeline-blending target is drawn from gh2.org.in's summary of state green hydrogen policies; this piece did not read Rajasthan's own policy notification text directly and recommends checking the state government's own current text before citing the figure as precise or still current.

2025 and 2026: still a roadmap, not yet a rule

Nothing found for this piece shows PNGRB finalising a national hydrogen-blending percentage through the most recent reporting checked. The September 2025 Business Standard report describing PNGRB as still drafting blending and transport regulations, and needing Act amendments to formally regulate the activity, is the most concrete recent status update located. PNGRB's World Bank-backed roadmap work continued through 2025, with case-study filings dated June and September of that year. Industry commentary from January 2026 (Indian Infrastructure) discusses hydrogen blending as an emerging, "future-ready" complement to CNG and biogas within the CGD sector, but frames it as still pending a unified CGD policy rather than describing a finalised blending rule. Taken together, the evidence points to a programme still at the roadmap-and-pilot stage as of the most recent check for this piece — not one operating under a settled national blend standard, at 10% or any other figure.

The September 2025 PNGRB regulatory-drafting status is from Business Standard. The June and September 2025 World Bank-roadmap case-study filings are from PNGRB's own hosted CSR report PDFs. The January 2026 industry commentary describing hydrogen blending's position within the CGD sector is from Indian Infrastructure's coverage; this piece searched specifically for, and did not find, any PNGRB notification through 2026 finalising a national blend percentage.

What doesn't follow from any of this

None of this should be read as hydrogen blending being a paper exercise in India — three named, PNGRB-approved pilots are real, running, and in at least one case (Surat) explicitly planning to scale well past 10%, toward 20%, over time. What doesn't follow is treating "up to 10%" as PNGRB's declared national or pilot-programme target: that figure traces to a GAIL engineering presentation PNGRB happens to host, not a PNGRB policy statement, and the pilots actually approved so far mostly sit below it. It also doesn't follow that the technical safety case for any particular blend percentage has been settled by a comprehensive Indian study; the approvals granted so far look staged and pilot-specific, which is a reasonable regulatory posture for a new technology, but is a different thing from a validated national ceiling. Readers who need a precise, current blend-percentage figure for a specific network or a specific regulatory purpose should check PNGRB's own published orders and PESO's pilot-specific approvals directly, rather than treating this piece's summary, or the "10%" figure in wider circulation, as settled.

Sources and caveats