Registration Dossier
Registration Dossier
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A mixture of isomers of: 1,1'-[(3,5(or 2,4 or 4,6 or 2,6)-dihydroxy-o(or m or p)-phenylene)bis(azo-meta-phenyleneazo{1-[3-(dimethylamino)propyl]-1,2-dihydro-6-hydroxy-4-methyl-2-oxopyridine-5,3-diyl})]dipyridinium-dichloride-dihydrochloride; 1-(1-[3-(dimethylamino)propyl]-5-{3-[x-(4-{1-[3-(dimethylamino)propyl]-1,6-dihydro-2-hydroxy-4-methyl-6-oxo-5-pyridinio-3-pyridylazo}phenylazo)-2,4(or 2,6 or 3,5 or 4,6)-dihydroxyphenylazo]phenylazo}-1,2-dihydro-6-hydroxy-4-methyl-2-oxo-3-pyridyl)pyridinium-dichloride-dihydrochloride (where x is variable)
EC number: 404-540-1 | CAS number: 159405-95-5 BRAUN HM 2763; BROWN HM 2763; BRUN HM 2763; BRUNO HM 2763
Toxicity to aquatic plants other than algae
Administrative data
Link to relevant study record(s)
Description of key information
EC50 (7d) > 100 mg/l for frond numbers growth rate.
Key value for chemical safety assessment
- EC50 for freshwater plants:
- 100 mg/L
- EC10 or NOEC for freshwater plants:
- 0.25 mg/L
Additional information
Toxicity of test substance to aquatic plants other than algae was assessed in a 7 -day semi-static test on lemna gibba according to OECD guideline 221. The following nominal concentrations of the test item were tested: 0.10, 0.32, 1.0, 3.2, 10, 32 and 100 mg/l along with a control. The test medium renewal occurred on day 2 (duration 48 h), 3 (duration (24 h), 5 (duration 48 h). Mean measured concentrations were calculated as the time weighted means of the concentrations measured at the start and end of the 48 h interval (day 0 - day 2) and the 24 h interval (day 2 - day 3). Biological results were related to mean measured concentrations. In particular, mean measured concentrations were: 0.035, 0.14, 0.51, 2.3, 9.0, 32, 105 mg/l.
The following results were obtained:
EC50 (7d) > 105 mg/l for frond numbers growth rate, dry weight growth rate, frond mortality.
In particular, inhibition of growth rate at 105 mg/l during the 7-day exposure period is 41.7 % and 23.82 % for frond numbers and dry weight, respectively.
EC10 (7d) = 0.25 mg/l for frond numbers growth rate, 2.8 mg/l for dry weight growth rate, > 105 mg/l for frond mortality.
NOEC (7d) = 0.035 mg/l for frond numbers growth rate, 0.51 mg/l for dry weight growth rate, 105 mg/l for frond mortality.
ECx concentrations were calculated by Probit analysis; NOEC and LOEC values were calculated by Willams t-test or Welch t-test.
By following a precautionary approach, an EC50(7d) = 100 mg/l is used in the chemical safety assessment.
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