Readily Biodegradable

It’s most common to consider the biodegradation in an aerobic environment (where oxygen is present).

There are several standardized methods to evaluate the rate of biodegradation for a chemical substance. The standards that most eco labels refer to are OECD or ISO. Most surfactants and several other substances are evaluated and noted in the DID-list[1].

Choice of standard depends on the characteristics of the substance, such as solubility in water. Depending on method there are three different factors that are measured, production of carbon dioxide (CO₂), consumption of oxygen or reduction of organic carbon.

A substance is considered Readily Biodegradable if it meets the criteria in OECD 301, OECD 310 or corresponding method. In an anaerobic environment it is ECETOC nr 28, ISO 11734, OECD 311 or corresponding method.

• >60% ThCO2 = over 60% of the theoretically calculated max production of CO₂ must be produced.
• >60% ThOD = over 60% of the theoretically calculated consumption of oxygen must be consumed.
• >70% DOC = over 70% of the organic carbon must have disappeared.

For inorganic substances biodegradation cannot be tested in the same manner. For those the DID-list states that nutrients are to be considered Readily Biodegradable whiles the rest, such as silicates, are not.

The tests cannot be done on mixtures as the results are too uncertain. Biodegradation for chemical mixtures/products is instead evaluated from included substances.

The propellant DME is not readily biodegradable, but it has a short atmospheric lifetime of about 5 days. It’s degraded to substances that all are readily biodegradable. It can therefor be accepted in a product marked readily biodegradable.

Criteria- for a chemical VEIDEC product to be considered Readily Biodegradable.

• 99% of ingoing substances, present in above 0,1%, must be Aerobic Readily Biodegradable
• Surfactants classified as H400 and/or H410/411/412/413 must also be anaerobic readily biodegradable
• Substances that are not biodegradable and bioaccumulating, toxic and/or harmful for the environment, are not allowed
• The < 1% potentially biodegradable or non-biodegradable substances are only allowed if they cannot be replaced by a readily biodegradable substance.
• Inorganic substances such as water, nutrients and other natural elements are allowed
• Lubricants have some adjusted criterium, criteria for amounts (weight%)