Biodegradable vs compostable bags: what procurement teams need to know

Every procurement brief we read these days mentions "biodegradable" or "compostable" bags — often interchangeably. They're not the same thing, and confusing them can put your organisation on the wrong side of state plastic bans. Here's the difference in plain language.

Biodegradable

A biodegradable bag is one that breaks down over time through the action of microorganisms, oxygen, light, or heat. There is no universal standard for how long that should take, or what residues are acceptable. In India, most "biodegradable" bags are LDPE or HDPE with an oxo-biodegradable additive that helps the polymer fragment under sunlight and heat. They're a transitional option — useful where composting infrastructure doesn't exist, but they do not always meet state-level compostable bag mandates.

Compostable

Compostable bags are held to a much stricter specification. The Indian Standard IS/ISO 17088 — which harmonises with the international ISO 17088 standard — defines compostable plastics as those that fully break down into water, carbon dioxide, and biomass within a defined timeframe in industrial composting conditions, with no toxic residue. Certification is issued after disintegration, biodegradation, and ecotoxicity tests.

Home composting vs industrial composting

IS/ISO 17088 certifies industrial compostability — controlled temperature, humidity, and microbial conditions. A bag certified to this standard will degrade more slowly in a home compost bin, where conditions are colder and less controlled. If you need home-compostable bags, ask specifically for the home-compost spec — it is a stricter subset.

Which should you buy?

• Urban local bodies with wet-waste collection → IS/ISO 17088 compostable for segregated household organic waste.
• Retail & D2C brands in states with plastic bans → IS/ISO 17088 compostable carry bags.
• Industrial use with no composting pipeline → biodegradable PE as a transitional option, with a plan to migrate.
• Food service → compostable, and ideally food-grade certified.

The right answer is whichever one your downstream waste stream can actually handle. A beautifully-certified compostable bag in a landfill is just a more expensive plastic bag. Map the bag to the treatment facility before you buy.