Cyclohexanamine, 4,4'-methylenebis[2,6-dimethyl-

Endpoint summary

Additional information

The most sensitive organisms regarding acute exposure to 4,4'-diamino-3,3',5,5'-tetramethyldicyclohexylmethan (CAS 65962-45-0) are algae (72 -h ErC50 = 5.0 mg/L, BASF SE, 2013). The lowest chronic effect value was determined in an algae study (72 -h ErC10 = 1.55 mg/L; BASF SE, 2013).

 

Short-term toxicity to fish:

Acutely harmful to fish.

No experimental data are available for 4,4'-diamino-3,3',5,5'-tetramethyldicyclohexylmethan (CAS 65962-45-0). Therefore a read-across approach to two structurally similar substances was performed.

The key study was performed on 2,2'-dimethyl-4,4'-methylenebis(cyclohexylamin) (CAS 6864-37-5) according to OECD 203 (NITE 2002) with Oryzias latipes. The 96-LC50 was determined to be 22.4 mg/L, the NOEC was 16 mg/L and the LC100 was 30 mg/L. The result is supported by a static-test study on CAS 6864-37-5 according to German industrial standard (DIN) 38412/15 (BASF 1988) performed with Leuciscus idus as test species. A 96-h LC50 of 31.6 mg/l was determined for non-neutralized samples (expressed as geometrical mean). The NOEC was determined to be 21.5 mg/l and the LC100 46.4 mg/l. Because DMD changes the pH in water, a neutralized sample with the highest test concentration (100 mg/l) was tested in addition. For this neutralized sample a diminution of the toxic effects was observed. 

An additional supporting study is a test performed on 4,4'-methylenebis-cyclohexanamine (CAS 1761-71-3) also performed according to German Industrial Standard DIN 38412, Part 15 using Leuciscus idus as test species (BASF AG, 1988; report no. 10F0562/875273).

The 96-h LC50 of 68.1 mg/L was determined for non-neutralised samples. A neutralised sample lead to a significant reduction of the mortality (96-h LC50 > 100 mg/L).

 

Long-term toxicity to fish:

No data available.

In Annex IX of Regulation (EC) No. 1907/2006, it is laid down that long-term toxicity to fish shall be proposed by the registrant of the chemical assessment indicates the need to investigate further the effects on fish.

According to Annex I of this regulation, the chemical safety assessment triggers further action when the substance or the preparation meets the criteria for classification as dangerous according to Directive 67/548/EEC or Directive 1999/45/EC or is assessed to be a PBT or vPvB.

The hazard assessment of 4,4'-Diamino-3,3',5,5'-tetramethyl-dicyclohexylmethane shows that the substance is not a PBT nor a vPvB substance. The results from short-term toxicity tests on fish, Daphnia and algae demonstrate that invertebrates are the most sensitive trophic level tested. Therefore, it may be concluded that results from a long-term test in fish would not reveal a greater hazard than already determined by the available data. Therefore, and for reasons of animal welfare, a chronic test on fish is not provided.

 

Short-term toxicity to aquatic invertebrates:

Acutely toxic to aquatic invertebrates.

The key study (GLP-guideline study according to OECD 202) determined a 48 -h EC50 of 8.95 mg/L. The nominal concentrations were analytically verified and all validity criteria were met in the test. Based on this data, the substance is acutely toxic to aquatic invertebrates.

 

Long-term toxicity to aquatic invertebrates:

Chronically not toxic to aquatic invertebrates.

No experimental data is available for 3,3’,5,5’-tetramethyl-4,4’-diaminodicyclohexylmethane (CAS 65962 -45 -0). Using a read-across approach to the structurally similar substance 2,2'-dimethyl-4,4'-methylenebis(cyclohexylamine) (CAS 6864 -37 -5), data for a study following OECD 211 using Daphnia magna as the test species are available. The test performed by NITE (2003) was identified as the key study. The 21-d NOEC was determined to be 4.0 mg/L.

 

Toxicity to aquatic algae and plants:

Acutely toxic to aquatic algae.

The key study (GLP-guideline study according to OECD 201) determined a 72 -h ErC50 of 5.00 mg/L and a 72 -h ErC10 of 1.55 mg/L. The nominal concentrations were analytically verified and all validity criteria were met in the test. Based on this data, the substance is acutely toxic to freshwater algae.

 

Toxicity to microorganisms:

The inhibition of the degradation activity of activated sludge in a STP is not anticipated when introduced in appropriate low concentrations.

No experimental data are available for 4,4'-diamino-3,3',5,5'-tetramethyldicyclohexylmethane (CAS 65962-4-50). Therefore a read across approach to structurally similar substances was made to assess the toxicity to microorganisms. The selected substances were 2,2'-dimethyl-4,4'-methylenebis(cyclohexylamine) (CAS 6864-37-5) and 4,4'-methylenebis(cyclohexylamine) (CAS 1761-71-3).

As key study a short-term respiration inhibition test on the analogous substance 4,4-methylenebis[2-methyl-]cyclohexanamine (CAS 6864-37-5) according to ISO 8192 with domestic activated sludge was identified (BASF 1990).The 30-min EC20 was determined to be 160 mg/L.

The following results support this finding:

- CAS 6864-37-5: BASF AG (1987). Report no. 9/0787/87. DIN 38412, part 8 (P. putida, growth inhibition): 17-h EC50 = 96 mg/L (nominal)

- CAS 1761-71-3: BASF AG (1987). Report no. 87/0792. DIN 38412, part 27 (draft; P. putida respiration inhibition): 30-min EC0 = 80 mg/L (nominal)

- CAS 1761-71-3: BASF AG (1986). Report no. 01.114/86. ISO 8192 (industrial act. sludge, respiration inhibition): 30-min EC20 > 1000 mg/L; 180-min EC20 < 100 mg/L (nominal)