India Proposes Revised Standard for DME-Blended LPG, Caps Mixing at 8%

On 1 April 2026, the Bureau of Indian Standards (BIS) issued a draft revision of its standard for dimethyl ether (DME) blended liquefied petroleum gas (LPG), proposing stricter limits and updated specifications to align with safety and technological advancements.

Titled “Dimethyl Ether (DME) Blended Liquefied Petroleum Gas (LPG) - Specification (First Revision of IS 18698)”, the draft aims to regulate the use of DME as an alternative fuel blended with LPG for domestic, commercial, and industrial applications, excluding automotive use.

Key Change: Lower DME Limit

The most significant revision is the reduction in the permissible DME content. The previous standard allowed blending up to 20 percent DME. However, the new draft caps the DME proportion at 8 percent by mass, based on the findings from a 2025 research study conducted by the LPG Equipment Research Centre in Bengaluru. The study highlighted compatibility concerns between higher DME concentrations and elastomers used in LPG distribution systems.

Focus on Safety and Compatibility

DME (CAS No. 115-10-6) is a cleaner-burning fuel that can be produced from biomass, coal, or natural gas. It is being explored as a partial substitute for LPG amid rising energy demand. However, BIS has emphasized that safety remains paramount. The revised standard therefore seeks to ensure that DME-blended LPG remains compatible with existing household infrastructure, including gas stoves, regulators, valves, and rubber hoses.

The draft also sets limits on parameters such as vapour pressure, sulphur content, corrosion levels, and the absence of free water. Additionally, the fuel must contain an odorant to enable leak detection.

Testing and Quality Assurance

To ensure quality and uniformity, the standard prescribes detailed methods for sampling and testing, referencing both Indian and internationally recognized procedures such as ASTM and ISO test methods. In case of disputes, the specified referee test methods will prevail.

Packaging and Labelling Norms

The draft outlines clear requirements for the packaging and marking of cylinders. Containers must display key details including the product name, weight, vapour pressure, and manufacturer information, along with a mandatory “FLAMMABLE” warning label.

Consultation Open

BIS has invited comments from stakeholders on the draft until 1 May 2026. Comments must be submitted via the prescribed template on the BIS portal. This is part of India’s broader effort to integrate cleaner alternative fuels while maintaining safety and reliability in existing energy systems.

Once finalized, the revised standard is expected to guide manufacturers and suppliers in the adoption of DME-blended LPG across the country.