Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
0.098 mg/L
Assessment factor:
1 000
Extrapolation method:
assessment factor
PNEC freshwater (intermittent releases):
0.982 mg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
0.01 mg/L
Assessment factor:
10 000
Extrapolation method:
assessment factor

STP

Hazard assessment conclusion:
PNEC STP
PNEC value:
12.5 mg/L
Assessment factor:
1
Extrapolation method:
assessment factor

Sediment (freshwater)

Hazard assessment conclusion:
PNEC sediment (freshwater)
PNEC value:
1.89 mg/kg sediment dw
Extrapolation method:
equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
0.189 mg/kg sediment dw
Extrapolation method:
equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
PNEC soil
PNEC value:
0.321 mg/kg soil dw
Extrapolation method:
equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

Acute aquatic toxicity data are available for fish, daphnia, algae, and bacteria. EC/LC50 values for fish and daphnia were > 100 mg/L. As these data provide adequate information on the aquatic toxicity hazard of this substance, no long term studies with fish or aquatic invertebrates are proposed.

The acute EC50 for algal growth rate was 98.2 mg/L and the chronic NOEC for growth rate was 42.7 mg/L. The results for the growth rate endpoints are being used as the key values for the chemical safety assessment for algal toxicity.  

The toxicity to microorganisms was determined using a Pseudomonas cell multiplication inhibition test which resulted in an EC50 of 690 mg/L.

Toxicity data for terrestrial organisms are not available. As the substance is readily biodegradable and has a low adsorptive (log Koc < 3) as well as a bioaccumulative (log Kow < 3) potential, direct and indirect exposure of the soil compartment is unlikely. The equilibrium partitioning method is utilized to assess the hazard to terrestrial organisms.

Conclusion on classification

Adequate acute data for aquatic invertebrates, fish, and aquatic algae are available along with ready biodegradation and log Kow data for assessing classification according to CLP and GHS criteria. In addition the chronic NOEC from the algal toxicity study allows further assessment of classification according to GHS and the March 2011 revision of the CLP for substances with adequate chronic data available. Methyl n-amyl Ketone (MAK) is rapidly degradable based upon a demonstration of ready biodegradability. 

MAK also has a log Kow of < 4. Based upon the most sensitive acute endpoint of an algal EC50 for growth rate of 98.2 mg/L, and the most sensitive chronic endpoint from the algal study NOEC of 42.7 mg/L, in conjunction with the persistence and bioaccumulation data, MAK does not meet the criteria for classification for environmental effects under the European CLP regulation.  However, under the GHS regulations MAK would be classified as Acute Category 3 based upon the algal EC50 being >10 but < 100 mg/L. MAK would not be classified for chronic effects under the GHS regulations.