The German Water Hazard Regulations

Full translated name is “Regulation on the Classification of Substances hazardous to waters into Water Hazard Classes” (Verwaltungsvorschrift wassergefährdende Stoffe – VwVwS) or abbreviated to either WGK (Wassergefährdungsklassen) or VwVwS.

This regulation came into force originally in November 1996 and has been modified several times since. The regulation sets out that all substances are either non-hazardous to water (ngw, nicht wassergefährdende) or assigned to one of three classes:

                WGK 1: Low hazard to waters

                WGK 2: Hazard to waters

                WGK 3: Severe hazard to waters

When a substance is not named in the regulations it is possible to use the R-phrase classifications for a substance to calculate the WGK classification, it must be kept mind that this always depends on the most sensitive data item.

Number of Points	1	2	3	4	5	6	7	8	9
Ecotoxicity and degradation / bioaccumulation				52/53		51/53		50/53
Ecotoxicity			52			50
Degradation / bioaccumulation			53
Acute oral and/or dermal toxicity tomammals	22 65 21 20/22 21/22 20/21/22 20/21		25 24 23/25 24/25 23/24/25 23/24		28 27 26/28 27/28 26/27/28 26/27
Carcinogenic and/or mutagenic effects		40							45 46
Irreversible effects		40/21 40/22 40/20/21 40/20/22 40/21/22 40/20/21/22		39/24 39/25 39/23/24 39/23/25 39/24/25 39/23/24/25		39/27 39/28 39/26/27 39/26/28 39/27/28 39/26/27/28
Repeated exposure		33 48/21 48/22 48/20/21 48/20/22 48/21/22 48/20/21/22		48/24 48/25 48/23/24 48/23/25 48/24/25 48/23/24/25
Toxic effects on reproduction		62 63		60 61
Harmful reaction with water		29 15/29

Table based on Annex 1 in "Guidelines for self-classifications"

Notes:

Not all evaluation points are allocated additively

There is no double tally of R-phrase points. The more sensitive characteristic is the only relevant one.

Example 1: A substance classified into R21/22 is only allocated 1 point and not 2 points.

Example 2: A substance classified into R22-24 is allocated 3 points not 1 or 4 points

Example 3: A substance classified into R22-40/21/22 is allocated 3 points

Example 4: A substance classified into R61-62 results in 4 points not 6 points

After calculating the total number of points, you can get the water hazard class:

Total points	Water hazard class (WGK)
0 to 4	1
5 to 8	2
9 or more	3

The substance can only be classified as “non-hazardous to waters” if the substance fulfils all of the following:

·         The total number of points is zero

·         Low solubility in water at 20⁰C, is less than 100 mg/l in the case of gases and solids or less than 10 mg/l in the case of liquids.

·         No toxicity at saturation levels (tested with at least two organisms – fishes, daphnia and algae).

·         Ready biodegradability in the case of organic liquids.

Mixtures

Mixtures are non-hazardous to water if they fulfil the following prerequisites:

• Their content of WGK 1 components is less than 3% by mass
• Their content of WGK 2 and 3 components are less than 0.2% by mass
• WGK 3 components, carcinogenic components or components of unknown identity have not been added.
• They do not contain any dispersants

You first of all need to determine the WGK of each component, if there is a component that is unknown then as a precaution WGK 3 will be assumed.

The components are taken into account when their concentration percentage is greater than the following thresholds:

• 0.1% for carcinogenic substances
• 0.2% for all other substances
• If carcinogenic substances are in the mixture and there fraction is less than 0.1%, the mixture will be classified at least as WGK 1; the same applies when the concentration percentage of WGK 3 substances are less than 0.2%

Ingredients (components)	Result
	WGK 3	WGK 2	WGK 1	Non-hazardous
WGK 3	>= 3%	0.2 to 3%	< 0.2% in case of additives	< 0.2% (no additives permited)
WGK 2		>= 5%	0.2 to 5%	< 0.2%
WGK 1			>= 3%	< 3%
Non-hazardous
R45 (carcinogenic)	>= 0.1%	>= 0.1% but WGK 2	< 0.1% in case of additives	< 0.1% (no additives permited)

Table based on Table 5 in "Guidelines for self-classifications"

Notes:

Example 1:.   If a mixture contains less than 5% of WGK 2 components an no WGK 3 components, this will classify the mixture as WGK 1

Example 2:.   If a WGK 3 component with a concentration of 0.05% is added to a substance non-hazardous to waters, the mixture is classified as WGK 1. If the substance contains this component as an impurity resulting from the production process, then it will be classified as “non-hazardous to waters”.

Example 3:.   (dilution) A mixture containing a total concentration of 20% of WGK 2 components and 80% of WGK 1 components will be classified as WGK 2. If the mixture is diluted with water at a ratio of 1:1, yielding a concentration of 10% of WGK 2 components, it is still classified as WGK 2. If the mixture is diluted as a ration of 1:4, the total concentration of WGK 2 components are now only 4% so the mixture will be classified as WGK 1.

 

 

Reference:

http://www.umweltbundesamt.de/wgs-e/archiv/vwvws170599.pdf