ISO 14852:2021

Overview

ISO 14852:2021 specifies a laboratory CO2-evolution method for determining the ultimate aerobic biodegradability of plastic materials in an aqueous medium. The standard exposes a plastic test material (the sole carbon source) to an inoculum from activated sludge under controlled aerobic conditions and measures the amount of carbon dioxide evolved. Results are expressed as the percentage of theoretical CO2 (ThCO2) and provide an indication of the material’s potential for aerobic biodegradation.

Key Topics and Requirements

• Test principle: Quantify evolved CO2 from microbial mineralization and compare with the theoretical maximum (ThCO2) to calculate percentage biodegradation.
• Inoculum: Activated sludge from wastewater treatment plants is used; soil and compost inocula are excluded in this edition.
• Test medium: Uses a synthetic inorganic medium (standard or optimized for higher test concentrations) with defined buffering and nutrients.
• Concentration range: Typical organic carbon concentrations 100–2 000 mg/L (note: lower ranges such as 20–40 mg/L have been validated).
• Environmental conditions: Incubation in dark or diffuse light at a constant temperature (preferably 20–25 °C ±1 °C), with agitation and aeration using CO2‑free air for up to two months.
• Optional analyses: Carbon-balance calculation (Annex C) to assess partitioning of carbon between CO2, biomass and residual material.
• Quality and validity: Includes inoculum activity checks, inhibition controls (see ISO 8192), and criteria for determining plateau/maximum biodegradation.
• Analytical options: Examples of CO2 measurement systems and apparatus are provided in Annexes A and B.
• Safety note: Activated sludge may contain pathogenic organisms - follow appropriate biosafety procedures.

Applications and Who Uses It

ISO 14852 is used by:

• Plastic manufacturers and compounders assessing biodegradability of polymers, copolymers, additives, plasticizers and water‑soluble polymers.
• Environmental and materials testing laboratories performing biodegradation certification and R&D.
• Regulatory bodies and product-certification schemes that require a standardized measure of potential aerobic biodegradability.
• R&D teams developing biodegradable formulations or evaluating impacts of additives on biodegradation.

Practical uses include screening new materials, supporting environmental claims, comparing formulations, and informing waste‑management decisions.

Related Standards

• ISO 8192 - methods to assess inhibitory effects on inoculum
• ISO 8245 - guidelines for TOC/DOC determination
• ISO 17556, ISO 9439, ISO 14851 - related biodegradation testing methods and terminology

Keywords: ISO 14852, aerobic biodegradability of plastics, CO2 evolution method, activated sludge inoculum, biodegradation testing, plastic materials biodegradability.