Certification Scope Verification for Industrial Compostable Packaging Materials
Verify industrial compostability claims by matching finished pack wall thickness and ink coverage against public register scope lines before shipping.
ISO 14855-1
Respirometric Method
Aerobic respirometry provides a controlled laboratory framework for determining the ultimate biodegradability of plastic materials and polymer-coated paperboards under optimized thermophilic composting conditions. Testing conducted under iso 14855-1 exposes ground test specimens to mature aerobic compost derived from municipal solid waste while regulating moisture levels, aeration rates, and temperature at fifty-eight degrees Celsius. The analytical apparatus routes synthetic air or carbon dioxide-free air through closed bioreactor vessels to stimulate microbial digestion of the carbonaceous substrate.
Infrared gas analysis or potassium hydroxide absorption traps measure the cumulative volume of carbon dioxide gas evolved by the microbes over a testing window extending up to six months.
Carbon Balance
Quantitative evaluation relies on comparing carbon dioxide evolution from the sample against the theoretical carbon content present in the starting polymer mass. Calculations governed by iso 14855-1 monitor microbial activity by measuring parallel reactors containing microcrystalline cellulose as a positive reference and empty compost as a baseline control. The test run reaches technical validity only when the positive cellulose control achieves greater than seventy percent biodegradation within forty-five days and the blank compost generates less than a specified ceiling of endogenous carbon dioxide.
Coated folding boxboards evaluated under this protocol must show the complete conversion of synthetic polymers, such as polybutylene succinate or polylactic acid dispersions, into gaseous mineralization products. High mineral filler loadings or halogenated flame retardants in the paper coating suppress respirometric activity, lowering the measured gas volume.
Test Scope
Operational boundaries restrict this respirometric protocol to controlled laboratory composting vessels, precluding direct extrapolations to backyard heaps, roadside litter, or aquatic environments. While iso 14855-1 quantifies molecular mineralization into carbon dioxide, it does not assess physical fragmentation sizes or certify complete absence of microplastic debris. Sourcing evaluations for compostable paperboard packaging require this standard alongside sieving fragmentation assays to verify overall industrial compostability.