1-methyltrimethylene dimethacrylate

Endpoint summary

Description of key information

EC50 fish (96h): 13.8 mg/l  (QSAR predicted from category trend analysis of 12 methacrylates)  (OECD 203 study with 1,3-BDDMA in progress)

EC50 algae (72h): 13 mg/l (based on growth rate) (HMRTF, 2021)

EC10 algae (72h): 9.19 mg/l (based on growth rate) (HMRTF, 2021)

EC50 Daphnia (21d): 17.1 mg/l

EC10 Daphnia (21d): 9.87 mg/l

The lowest aquatic toxicity value for 1,3-BDDMA is the 72 h-EC10 of 9.19 mg/L, based on the toxicity test with the freshwater alga Pseudokirchneriella subcapitata

Additional information

Short-term toxicity to fish

A new guideline-conform OECD 203 is in progress. 

Available data are: In a 48-h acute toxicity study, golden orfes (Idus melanotus HECKEL) were exposed to 1,3-BDDMA nominal concentrations of 25, 30 and 40 mg/L under static conditions. 

The 48-h EC50 was 32.5 mg/L. The 48-h NOEC was 25 mg/L.

EC50 fish (96h): 13.8 mg/l  (QSAR predicted from category trend analysis of 12 methacrylates), key study (QSAR wird vermutlich nicht akzeptiert, löschen)

 

Short-term toxicity to aquatic invertebrates

No experimental data on short-term toxicity of 1,3-BDDMA are available. In accordance with REACH regulation Annex VII, 9.1.1., column 1, long-term toxicity data are provided instead. The test item induced adult mortality of 100% after 21 days in concentration level 74.6 mg/L, 10% adult mortality in the concentration levels 2.81, 6.26 and 13.8 mg/L. No mortality was obsereved in the concentration level 31.6 mg/L and in the control. In conclusion, the EC50 for mortality was 48.6 mg/L.

 

Toxicity to aquatic algae

In a 72 hour acute toxicity study, the cultures of Pseudokirchneriella subcapitata HINDÁK CCAP 278/4 (axenic) were exposed to 1,3-BDDMA at nominal concentrations of 0 (control), 1.0, 3.16, 10.0, 31.6 and 100 mg/L under static conditions in accordance with the OECD guideline 201. 

Microscopic evaluation of the cells at start and end of the incubation period revealed no morphological abnormalities.

The NOEC, EC10 and EC50 values based on growth rate were 1.00 mg/L, 9.19 mg/L and 13.00 mg/L, respectively. 

 

Long-term toxicity to fish

Long-term testing in fish is waived for 1,3-BDDMA since the substance is readily biodegradable. The risk characterisation shows that the PEC/PNECaqua ratio for the aquatic environment is <1, indicating no need for further information or testing. According to REACH regulation Annex IX, 9.1. column 2, long-term toxicity testing shall only be considered when the chemical safety assessment indicates the need for further investigations. Thus, no long-term toxicity testing is required for 1,3-BDDMA. Please note that the acute toxicity study with fish is currently being conducted.

 

Long-term toxicity to aquatic invertebrates

The 21-day-chronic toxicity of 1,3-BDDMA to Daphnia magna Straus was studied under under semi-static conditions with a renewal of the test solutions every two or three days over a period of 9 days according to OECD guideline 211. Daphnids were exposed to control and test chemical at nominal concentrations of 1.00, 3.16, 10.00, 31.60 and 100 mg/L. 

The 21 day EC50 based on mortality was 48.6 mg/L. The 21 day EC50 based on reproductive effects was 17.1 mg/L. The 21 d EC10 based on reproduction was 9.87 mg/L.The 21-day NOEC based on reproduction was 6.26 mg/L.

The sublethal effects included were intrinsic rates of natural increase (IR)of the survived parental daphnidsr, appearance of first brood, number of stillborn juveniles and aborded eggs and growth (total body length and mean dry weight) of survived parentals.

Production of offspring in the treated groups indicated that 1,3-BDDMA had an effect on the reproduction at concentrations greater than 6.26 mg/L. The most sensitive end point was the reduction of the reproductive output.        

 

Toxicity to microorganisms

The toxicity of 1,3 -BDDMA to microorganisms was investigated during a ready biodegradation study according to OECD guideline 301B (CO2 Evolution Test) over a period of 28 days and using domestic sewage as inoculum.

The biodegradation rate was determined by measurement of CO2 evolution. Inoculum blank and procedural/functional control with the reference substance sodium acetate were performed.

The functional control reached the pass level >60% after 14 d (68.5%).

The 10-day window started on day 6. Biodegradation totalled 57% at the end of the 10 day window (day 16) and 74% at the end of the test period.

A degradation of 60% has to be reached in a 10-day window within 28 days in order to classify the test substance as readily biodegradable. Based on this criterion, 1,3-BDDMA is not readily biodegradable. But as the pass level is almost fulfilled (degradation slightly below 60%), the test substance can be considered as readily biodegradable and inherently biodegradable.

 

In conclusion, the lowest aquatic toxicity value for 1,3-BDDMA was the 72 h-EC10 of 9.19 mg/L, based on the toxicity test with the freshwater alga Pseudokirchneriella subcapitata.