shelf life (product shelf life)

Shelf life is the maximum period a packaged product retains its specified quality, nutritional value, and safety under defined storage conditions, after which physical, chemical, or microbiological degradation makes it unsuitable for sale or use. For dried digestate, organic fertiliser pellets, and bio-compost products from CBG and composting operations, shelf life is typically 6–12 months when stored in moisture-proof bags at ambient temperature in covered warehouses.

The degradation mechanisms differ by product:

• Moisture re-absorption — dried pellets at 8–12% moisture can absorb humidity from coastal-belt warehouses, leading to clumping, mould growth, and loss of nutrient guarantee
• NPK leaching and volatilisation — urea-coated or nitrogen-enriched products lose ammonia over time, particularly under heat; total nitrogen can drop 10–20% over a year
• Microbial regrowth — if moisture rises above 15%, residual bacteria reactivate, generating heat and ammonia inside bags
• Physical degradation — pellet integrity breaks down with handling, producing dust that reduces marketable yield

Indian regulatory and commercial requirements anchor shelf life at the labelling stage. The Fertiliser Control Order (FCO) requires every bag of City Compost, Phosphate-Rich Organic Manure (PROM), or bio-organic fertiliser to declare manufacturing date and best-before date, typically 6 months for compost and 12 months for granulated PROM. The Bureau of Indian Standards (BIS) and FCO testing protocols allow up to 10% variation in declared NPK at the time of testing within shelf life.

Storage best practice in Indian conditions includes HDPE-laminated bags (not jute), pallet storage off concrete floors (which wick moisture in monsoon), shaded warehouses, and stock rotation on a first-in-first-out basis. CBG plants selling digestate as packaged organic fertiliser must factor in 5–10% shelf-life loss as inventory write-off in financial models, particularly in coastal Maharashtra, Kerala, and Tamil Nadu where humidity is high year-round.