Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
no data available
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999
Report date:
1999

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
α,2-dichlorotoluene
EC Number:
210-258-8
EC Name:
α,2-dichlorotoluene
Cas Number:
611-19-8
Molecular formula:
C7H6Cl2
IUPAC Name:
1-chloro-2-(chloromethyl)benzene
Details on test material:
Source: Wako Pure Chemical Industries, Ltd.,
Purity 99.6 %,
Lot No. PAM5243
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
no data availble

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
no data available

Test solutions

Vehicle:
yes
Details on test solutions:
Dispersant and Concentrations: Polyoxyethylenesorbitan fatty acid ester, 10 mg/l test solution

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
a) Strain Number: ATCC22662
b) Supplier/Source: American Type Culture Collection
c) Pretreatment: Subcultured for 3 days in OECD medium before use.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h
Post exposure observation period:
no data available

Test conditions

Hardness:
no data available
Test temperature:
23 +/- 2 °C
pH:
7.9 - 8.0 at test start (0 hours)
8.0 - 10.5 after 72 h
Dissolved oxygen:
no data available
Salinity:
no data available
Nominal and measured concentrations:
Nominal Concentrations (as mg/l): 0, 0.10, 0.22, 0.46, 1.0, 2.2, 4.6 and 10
Details on test conditions:
Medium: OECD medium (Table 1)
Exposure Vessel Type: 100-ml Medium in a 500-ml Conical Flask
Number of Replicates: 3
Initial Cell Number: 10,000 cells/ml
Light Condition: 4,000 - 5,000 lux, continuous
Reference substance (positive control):
not specified

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.045 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
0.78 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
test mat.
Basis for effect:
biomass

Any other information on results incl. tables

Measured concentrations at the beginning (0 hr) and the end
(72 hr) of the test were ranged within 66 - 91% and 19 - 43%
of the nominal concentrations, respectively. Because most of
the measured concentrations were lower than 80% of the
nominal, the time-weighted concentrations were used to
calculate effect values (Table 2).

Table 2.Measured concentrations of the test solutions in the
72-hour growth inhibition test on Selenastrum capricornutum
========================================================
Nominal       Measured        Time       Measured/Nominal
concn.        concn.          -weighted  (%)
(mg/l)       (mg/l)           mean
              -------------             ---------------
              0 hr    72 hr   (mg/l)     0 hr   72 hr
-------------------------------------------------------
Control       <0.005  <0.005   ---       ---     ---
Solv. Control <0.005  <0.005   ---       ---     ---
0.10          0.0833  0.0201   0.0445    83      20
0.22          0.185   0.0419   0.0964    84      19
0.46          0.303   0.0983   0.182     66      21
1.0           0.912   0.427    0.639     91      43
2.2           1.59    0.591    1.01      72      27
4.6           3.49    1.15     2.11      76      25
10            8.13    2.32     4.63      81      23
========================================================

[Water Chemistry]
Table 3.The pH values of the test solutions in the 72-hour
Growth inhibition test on Selenastrum capricornutum.
======================================
Nominal concn.           pH
                  --------------------
(mg/l)            0 hour    72 hours
--------------------------------------
Control           8.0        10.4
Solvent control   7.9        10.3
0.10              7.9        10.4
0.22              8.0        10.5
0.46              7.9        10.4
1.0               7.9        10.4
2.2               7.9         8.9
4.6               7.9         8.2
10                7.9         8.0
=======================================


[Effect Data]
Area method:
  EbC50 (0 - 72 hr)  = 0.78mg/l (Table 4 - 6)
  NOEC (0 - 72 hr)   = 0.045 mg/l (Table4, 5 & 7)
Rate method:
  ErC50 (0 - 24 hr)  = 1.5 mg/l
      (95% confidence limits: 1.2 - 1.9 mg/l) (Table 4 - 6)
  NOEC (0 - 24 hr)   = 0.096 mg/l (Table4, 5 & 7)
  ErC50 (24 - 48 hr) = 1.2 mg/l
     (95% confidence limits: 1.16 - 1.21 mg/l) (Table 4 - 6)
  NOEC (24 - 48 hr) = 0.64 mg/l (Table4, 5 & 7)
  ErC50 (24-72hr)   = 1.2 mg/l
     (95% confidence limits: 1.1 - 1.3 mg/l) (Table 4 - 6)
  NOEC (24 - 72 hr) = 0.18 mg/l (Table4, 5 & 7)

Table 4.Mean cell concentrations and their standard
deviations (S. D.) in the test cultures and controls
=======================================================
Nominal concn   Cell concentration (x 10000 cells/ml)
(mg/l)                 0 hr   24 hr   48 hr    72 hr
-------------------------------------------------------
Control         Mean   1.0    6.98    34.51    89.12
                S. D.  0.0    0.28     1.37     0.65
-------------------------------------------------------
Solvent control Mean   1.0    7.19    37.96    90.52
                S. D.  0.0    0.23     2.91     3.79
-------------------------------------------------------
0.10            Mean   1.0    6.82    35.32    85.47
                S. D.  0.0    0.45     1.07     4.37
-------------------------------------------------------
0.22            Mean   1.0    6.49    33.39    76.51
                S. D.  0.0    0.37     3.08     6.09
-------------------------------------------------------
0.46            Mean   1.0    5.70    30.85    65.81
                S. D.  0.0    0.24     0.98     0.91
-------------------------------------------------------
1.0             Mean   1.0    5.58    28.18    61.64
                S. D.  0.0    0.37     2.38     4.74
-------------------------------------------------------
2.2             Mean   1.0    2.73    7.23     17.51
                S. D.  0.0    0.11    0.30      1.01
-------------------------------------------------------
4.6             Mean   1.0    1.90    2.00      2.17
                S. D.  0.0    0.06    0.06      0.10
-------------------------------------------------------
10              Mean   1.0    1.55    1.59      1.58
                S. D.  0.0    0.05    0.03     0.08
=======================================================


Table 5.Percent inhibition of the cell growth (IA) and the
average specific growth rates (Im) in the 72-hour growth
inhibition test on Selenastrum capricornutum
========================================================
Nominal     Area       Inhibition   Rate      Inhibition
concn.      A          IA (%)       M          Im (%)
            ---------------------   --------------------
(mg/l)      (0-72 hr)               0-24 hr)
--------------------------------------------------------
Control     20050800    ---         0.080918     ---
Solv. cont. 21099600   -5.23        0.082181   -1.56
0.10        19769600    1.40        0.079954    1.19
0.22        18151600    9.47        0.077859    3.78
0.46        16068400   19.86        0.072471   10.44
1.0         14899600   25.69        0.071574   11.55
2.2          3891600   80.59        0.041823   48.31
4.6           596400   97.03        0.026732   66.96
10            343600   98.29        0.018244   77.45
========================================================

Table 5.continue
=======================================================
Nominal     Rate       Inhibition   Rate     Inhibition
concn.      M          Im (%)       M          Im (%)
            ---------------------   -------------------
(mg/l)      (24-48 hr)              (24-72 hr)
-------------------------------------------------------
Control     0.066612    ---         0.053081     ---
Solv. cont. 0.069260   -3.98        0.052764    0.60
0.10        0.068548   -2.91        0.052675    0.77
0.22        0.068197   -2.38        0.051387    3.19
0.46        0.070396   -5.68        0.050988    3.94
1.0         0.067441   -1.24        0.050032    5.75
2.2         0.040579   39.08        0.038706   27.08
4.6         0.002138   96.79        0.002760   94.80
10          0.001073   98.39        0.000436   99.18
========================================================

Table 6.Calculated EC50 values
========================================================
                  Value   95% confidence limits  Ordinate
                 (mg/l)       (mg/l)
--------------------------------------------------------
EbC50 (0-72 hr)   0.78    not calculated         IA
ErC (0-24 hr)     1.5     1.2 - 1.9              Im
ErC (24-48 hr)    1.2     1.16 - 1.21            Im
ErC (24-72 hr)    1.2     1.1  - 1.3             Im
========================================================

Table 7.Calculated NOEC
========================================================
                  Value    Statistical       Parameter
                  (mg/l)   method
--------------------------------------------------------
NOEC (0-72 hr)    0.045    Dunnett (p<0.05)   IA
NOEC (0-24 hr)    0.096    Dunnett (p<0.05)   Im
NOEC (24-48 hr)   0.64     Dunnett (p<0.05)   Im
NOEC (24-72 hr)   0.18     Dunnett (p<0.05)   Im
========================================================

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 72 hour EbC50 of Selenastrum capricornutum was determiend to be 0.78 mg/L OCBC.
Executive summary:

OCBC was assessed in a chronic toxicity test to Selenastrum capricornutum, according to OECD guideline 201. Algae were exposed in a static test to the test item for 72 hours at nominal concentrations of 0.10, 0.22, 0.46, 1.0, 2.2, 4.6 and 10.0 mg/L. The 72 h EbC50 was determined to be 0.78 mg/L.