Claims of "compostable" plastics are closely scrutinised by regulators, certifiers, and consumers alike. To stand up to that scrutiny, manufacturers must show that materials truly biodegrade under composting conditions; not just fragment or partially break down. 

ISO 14855 testing provides robust, laboratory-based evidence of ultimate aerobic biodegradation in controlled composting environments, offering part of the evidencve required for compostability claims and demonstrate environmental responsibility with confidence. 

ISO 14855 specifies a method for determining the degree and rate of aerobic biodegradation of plastics under controlled composting conditions, by measuring the amount of carbon dioxide (CO₂) released as microorganisms metabolise the material. 

The test evaluates: 

• Extent of biodegradation relative to theoretical CO₂ 

• Microbial activity in compost 

• Material behaviour under thermophilic composting conditions 

• Performance compared to a reference material 

It is a cornerstone test for assessing industrial compostability. 

At Impact Solutions, ISO 14855 testing is carried out using temperature-controlled composting reactors designed to replicate industrial composting environments. 

A typical ISO 14855 programme includes: 

1. Preparation of test material to defined size and surface area. 
2. Mixing samples with mature compost containing active microorganisms. 
3. Incubation under aerobic conditions at elevated temperatures (typically ~58 °C). 
4. Continuous measurement of CO₂ evolution throughout the test period. 
5. Use of reference materials to confirm compost activity. 
6. Calculation and reporting of biodegradation as a percentage of theoretical CO₂. 

Testing typically runs for 45 to 180 days, depending on material type and degradation behaviour. 

ISO 14855 testing is widely used for: 

• Industrial compostable packaging 

• Food-contact compostable products 

• Compostable bags, films, and moulded items 

• Bio-based plastics and blends 

• Certification programmes (e.g. EN 13432, AS 4736) 

• Material R&D and formulation optimisation 

• Provides quantitative proof of compost biodegradation 

• Supports industrial compostability certification 

• Helps substantiate environmental and sustainability claims 

• Enables comparison of materials and formulations 

• Reduces the risk of non-compliance or greenwashing claims 

• Builds confidence with regulators, certifiers, and end users 

Q: Does ISO 14855 alone prove compostability?
No, it is a key component, but full compostability certification also requires disintegration, ecotoxicity, and compost quality testing. 

Q: What type of compost is used?
The test uses mature compost with active microbial populations under controlled laboratory conditions. 

Q: Is ISO 14855 suitable for home composting claims?
No, ISO 14855 reflects industrial composting conditions, not home compost environments. 

Have a question?

Speak to our specialists