Substances considered to pose little or no risk to the environment, The PLONOR LIST

1. What is the PLONOR List?

The PLONOR list is a list of chemicals the OSPAR commission considered to pose little or no risk to the environment. Therefore, the use and discharge of chemicals on the PLONOR list, do not need to be strongly regulated.

A substance must meet the following criteria to be classified under the ‘Green’ category in the PLONOR list:
    • Bioaccumulation: log POW < 3 or BCF < 100 or molecular weight > 700 g/mol,
    • Biodegradation: Readily biodegradable, and
    • Toxicity: LC50 or EC50 > 100 mg/l

Examples of substances considered to pose little or no risk to the environment (PLONOR) include several inorganics, acetic acid, ethanol, butanol, propanol, glycerine, attapulgite clay, bentonite, cellulose, lignite, sodium lignosulfonate, calcium lignosulfonate, iron lignosulfonate, starch without additives, sugarcane molasses and xanthan gum.

2. What is OSPAR?

OSPAR is the mechanism by which fifteen governments (Belgium, Denmark, Finland, France, Germany, Iceland, Ireland, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom) together with the European Union, cooperate to protect the marine environment in the Northeast Atlantic Ocean.

3. What is HOCNF?

Harmonised Offshore Chemical Notification Format (HOCNF) is a document/datasheet that tells you how the chemical/substance affects marine life. It applies to all chemicals used in offshore exploration and production activities in the OSPAR maritime area. It contains information on biodegradability, bioaccumulation, and toxicity. Norway employs a colour system to classify substances based on their effect on marine life.






·       Substances missing data

·       Substance on OSPAR’s priority list

·       Substance which are believed to be mutagenic or harmful to reproduction

·       Substance on REACH candidate list

·       Low biodegradability (BOD28 < 20%) and high bioaccumulation (POW ≥ 5)

·       Low biodegradability (BOD28 < 20%) and toxic (EC50 or LC50 ≤ 10 mg/l)

Not allowed to discharge under any circumstance


·       Organic substances that meet 2 of the 3 following criteria:

(a)   BOD28 < 60%

(b)   log POW ≥ 3 and molecular weight lower than 700g/mol

(c)    EC50 or LC50 ≤ 10 mg/l

·       Inorganic substance with high toxicity (EC50 or LC50 ≤ 1 mg/l)

·       Organic substances with low biodegradability (< 20%)

·       Polymers that have not been tested for ecotoxicology

Only discharged under special conditions


·       Substances that are not in black, red, or green category

·       20% ≤ BOD28 < 60%

·       Strong acids and bases that are exempt from ecotoxicology tests

Can generally be discharged by offshore industry


·       Substances on OSPAR’s PLONOR list

·       Substances on the list in REACH Annex IV

·       Some/individual substances in REACH Annex V

No risk to aquatic environment