What is ISO 9408 – Aerobic biodegradability of organic compounds in aqueous medium about?  
ISO 9408 is an International Standard that specifies a method, by determination of the oxygen demand in a closed respirometer, for the evaluation in aqueous medium of the ultimate biodegradability of organic compounds and wastewaters at a given concentration by aerobic microorganisms.
The method applies to organic compounds which:
- Are water-soluble under the conditions of the test
- Are poorly water-soluble under the conditions of the test, in which case special measures may be necessary to achieve good dispersion of the compound
- Do not reach and react with the CO2 absorbent
- Are volatile, provided that a suitable respirometer or suitable conditions (e.g. a smaller ratio of volume head space to volume liquid medium) are used
- Are not inhibitory to the test microorganisms at the concentration chosen for the test. The presence of inhibitory effects can be determined as specified in 7.3, or by using any other method for determining the inhibitory effect of a compound on bacteria
Who is ISO 9408 - Aerobic biodegradability of organic compounds in aqueous medium for? 
ISO 9408 on ‘aerobic biodegradability of organic compounds in aqueous medium’ is useful for: 
- The manufacturing industry
- The chemical industry
- Nuclear facilities
- Entities involved with wastewater management
- Factory managers
- Compliance teams
- Regulatory bodies
- Local authorities (government/municipality)
- Environmental bodies
- Water distribution and supply entities
- Senior management of companies
- Environment management teams at companies
- Risk management teams
- Quality control personnel
- Chemical specialists
- Entities involved in sewerage management
- Water research scientists
Why should you use ISO 9408 – Aerobic biodegradability of organic compounds in aqueous medium?  
ISO 9408 helps organizations become more conscious of the impact of their activities on the environment. ISO 9408 guides you with aspects of the test such as:
- Test environment
- Reagents
- Apparatus
- Procedure
- Calculation and expression of results
- Validity of results
- Test report
Annexes provide you with:
- Example of calculation of theoretical oxygen demand
- Correction of oxygen uptake for interference by nitrification
- Example of a biodegradation curve
- Closed respirometer illustration
ISO 9408 guidelines are a step towards a more responsible approach to waste management and water management. This helps organizations to become more environmentally conscious in their activities.
