Toxicity to aquatic plants other than algae.002 to 001

Toxicity to aquatic plants other than algae.002

Administrative data

Purpose flag:

supporting study

Study result type:

experimental result

Reliability:

4 (not assignable)

Data source

Reference

Reference Type:

publication

Title:

Toxicity of chlorine dioxide to early life stages of marine organisms.

Author:

Hose JE, Di Fiore D, Parker HS and Sciarrotta T

Year:

1989

Bibliographic source:

Bull Environ Contam Toxicol, 42: 315-319

Materials and methods

Principles of method if other than guideline:

Sublethal measurements of chlorine dioxide toxicity (germination success and vegetative growth) on the giant kelp (Macrocystis pyrifera).

GLP compliance:

no

Test materials

Identity of test material same as for substance defined in section 1 (if not read-across):

yes

Test material identityopen allclose all

Test material identity 1

Identifier:

CAS number

Identity:

10049-04-4

Test material identity 2

Identifier:

EC number

Identity:

233-162-8

Test organisms

Test organisms (species):

other: Macrocystis pyrifera

Details on test organisms:

Giant kelp

Study design

Test type:

no data

Test conditions

Test temperature:

(Monitored at the termination of the bioassay) Within the required limits of APHA (1980).

pH:

(Monitored at the termination of the bioassay) Within the required limits of APHA (1980).

Dissolved oxygen:

(Monitored at the termination of the bioassay) Within the required limits of APHA (1980).

Salinity:

(Monitored at the termination of the bioassay) Within the required limits of APHA (1980).

Results and discussion

Details on results:

A single exposure of chlorine dioxide produced effects in early life stages of marine organisms only at high doses. Germination of macrocystis pyrifera was significantly reduced at chlorine dioxide concentrations of 25 and 250 mg/L. At the highest dose, germination was decreased by about 80%. Germ tube length was significantly reduced only at 250 mg/L.

Any other information on results incl. tables:

Table: Effects of chlorine dioxide on early life stages of the giant kelp (Macrocystis pyrifera)

Concentrations which were significantly different from the control are starred.

Organism	Endpoint	Dose (mg/L)	Response (x + SD (n))
Giant sea kelp	% germination	0.0000	38.2 ± 7.5 (5)
		0.0025	48.2 ± 11.4 (5)
		0.0250	38.0 ± 6.7 (5)
		0.250	30.2 ± 6.9  (5)
		2.50	31.6 ± 9.3 (5)
		25.0	21.2 ± 5.3 (5) *
		250.0	8.0 ± 1.5 (5) *
	Germ tube length	0.0000	6.4 ± 0.5 (5)
		0.0025	5.7 ± 1.0 (5)
		0.025	5.9 ± 0.9 (5)
		0.250	5.6 ± 0.5 (5)
		2.50	6.9 ± 0.3 (5)
		25.0	5.9 ± 1.2 (5)
		250.0	3.9 ± 3.9 (5) *

Applicant's summary and conclusion

Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assi

Toxicity to aquatic plants other than algae.001

Administrative data

Purpose flag:

key study

Study result type:

read-across from supporting substance (structural analogue or surrogate)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

Study generated according to generally valid and internationally accepted testing guideline and performed under GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Materials and methods

Test guideline

Qualifier:

according to

Guideline:

other guideline: OECD Guideline 221 (revised draft document 2002)

Deviations:

yes

Remarks:

Swedish Standard (SIS) medium. Modified: NH4Cl was given as inorganic nitrogen source instead of NaNO3 to get sufficient recovery rates of concentration control analysis. growth sp. inhibition test"

GLP compliance:

yes

Test materials

Identity of test material same as for substance defined in section 1 (if not read-across):

no

Test material identityopen allclose all

Test material identity 1

Identifier:

CAS number

Identity:

7775-09-9

Test material identity 2

Identifier:

EC number

Identity:

231-887-4

Test material identity 3

Identifier:

IUPAC name

Identity:

sodium chlorate

Details on test material:

- Batch No.: 1E0103WF
- Purity: 99.66 %
- Appearance: Solid, yellow to orange powder
- pH-value: In aqueous solution: neutral
- water solubility (a.i.): Highly soluble (715 g/L)
- Recommended storage: Dry, cool, well ventilated place
- Storage at test facility: 7 ± 2 °C, protected from moisture and light

Analytical monitoring:

yes

Details on sampling:

At the start and the end of the test samples were taken for analyses.

Vehicle:

no

Details on test solutions:

- Dispersion treatment: Agitation 
- Procedures: 320 mg/L prepared with dilution water

Test organisms

Test organisms (species):

Lemna minor

Details on test organisms:

- Source/supplier: OekoTox Moser & Pickl Gbr, Stuttgart, Germany 
- Laboratory culture: yes 
- Method of cultivation: in 900 ml crystallization dishes, filled with 500 ml Swedish Standard (SIS) Medium.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

7 d

Test conditions

Test temperature:

24 ± 1 °C

pH:

6.60-6.64 at the start of the test and 5.23-5.95 at the end 

Nominal and measured concentrations:

- Nominal test concentrations: 0.0, 3.2, 10, 32, 100, 320 mg/L 
- The measured concentrations of the test substance were between 90 and 107% of the nominal concentrations, therefore the nominal values were 
used for the calculations

Details on test conditions:

Swedish Standard (SIS) medium, modified GROWTH/TEST MEDIUM CHEMISTRY: Swedish Standard (SIS) medium 
- pH: 6.5 ± 0.2
- Exposure vessel type: Crystallization dishes with a volume of 500 ml, covered with glass tops and filled with 200 ml test solution. 
- Number of replicates, plants per replicate: 3, 3 plants with 4 fronds each
- Intensity of irradiation: 6500-10000 lx (85-125 µmol/m2*s) 
- Photoperiod: continuous fluorescent light
- Number of plants (start and end of the test), number of fronds (on day 0, 2, 5 and 7) and dry weight (at the end of the test). 
On each observation day the pigmentation, destruction of roots etc. were determined.

Reference substance (positive control):

yes

Remarks:

Zinc chloride, 99.2% pure

Results and discussion

Effect concentrationsopen allclose all

Effect concentrations 1

Duration:

7 d

Endpoint:

EC50

Effect conc.:

134 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks (e.g. 95% CL):

33.7- > 320 mg/L

Effect concentrations 2

Duration:

7 d

Endpoint:

NOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

7 d

Endpoint:

NOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 4

Duration:

7 d

Endpoint:

NOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

frond number

Details on results:

Details on results 
Biomass growth (number of fronds): 
EC50 = 73.7 mg/L (95% c.i. 34.5-158 mg/L) 
LOEC = 32 mg/L NOEC = 10 mg/L 
Growth rate (number of fronds): 
EC50 = 134 mg/L (95% c.i. 33.7- > 320 mg/L) 
LOEC = 32 mg/L NOEC = 10 mg/L 
Biomass dry weight: 
EC50 = 128 mg/L (95% c.i. 28.0- > 320 mg/L) 
LOEC = 32 mg/L 
NOEC = 10 mg/L 
- Evaluation after day 7 (mean and standard deviation in brackets):

Conc (mg/L) log biomass Inhibition of
integral log biomass (%) 
control 7.49 (0.49) 
3.2 8.37 (0.29) -11.74 (3.88) 
10 8.30 (0.29) -10.75 (3.82) 
32 6.12 (0.44) 18.31 (5.81) 
100 3.25 (0.47) 56.58 (6.27) 
320 0.24 (0.11) 96.83 (1.50) 

Conc (mg/L) Specific Inhibition of 
growth rate specific growth rate (%)

control 0.350 (0.020) 
3.2 0.366 (0.020) -4.45 (5.08) 
10 0.355 (0.000) -1.44 (1.31) 
32 0.289 (0.010) 17.29 (3.15) 
100 0.204 (0.010) 41.74 (2.04) 
320 0.099 (0.20) 71.70 (6.18) 

Conc (mg/L) Doubling Biomass dw Inhibition of 
time of (mg) biomass dw (%) 
fronds (d) 

control 1.98 (0.12) 26.0 (2.1) 
3.2 1.90 (0.09) 29.5 (0.6) -4.87 (0.79) 
10 1.95 (0.03) 23.4 (0.9) 4.21 (1.52) 
32 2.39 (0.09) 15.4 (2.0) 20.37 (4.95) 
100 3.40 (0.12) 8.4 (0.6) 43.92 (2.81) 
320 7.00 (1.86) 4.2 (0.6) 70.78 (5.41) 

- Other observations: In the three highest concentrations the fronds were lighter green and partly covered with white spots at day 2. 
At day 5 the fronts in 320 and 100 mg/L were partly without pigmentation and in 32 mg/L fronds were partly covered with white spots.
At day 7 fronds in the three highest concentrations were partly without pigmentation.

Results with reference substance (positive control):

- Concentrations: 0.0, 0.32, 1, 3.2, 10, 32 mg/L 
- Results: 
- EC50 (biomass growth) = 9.5 mg/L (95% c.i. 1.8-50.2 mg/L) 
- EC50 (growth rate) = 5.2 mg/L (95% c.i. 1.1-24.6 mg/L) 
- EC50 (biomass dry weight) = 10.9 mg/L (95% c.i. 3.2-37.1 mg/L)

Reported statistics and error estimates:

ANOVA and Dunnett's test were used for determination of significant differences compared control replicates. 
If normality of equal variance failed Bonferroni t-test was carried out. Probit analysis for calculation of EC50, confidence intervals 
are calculated using.

Applicant's summary and conclusion

Conclusions:

Test conducted under GLP with analysis, analysis certificate and to relevant guideline. This study can be considered reliable without restrictions. 
The NOEC based on biomass dry weight is 10 mg/l. The lowest EC50 is based on biomass grwoth and is 73.7 mg/L (95% c.i. 34.5-158 mg/L).

Executive summary:

The effects of the test item Sodium Chlorate on growth of the monocotyledon species Lemna minor were determined according to the principles of OECD-Guideline 221 (Revised Draft Document July 2002), from October 29 to November 05, 2003 at DR.U.NoACK-LABORATORIEN, Sarstedt, Germany. The test item (batch number 1E01 03WF) contained 99.66 % Sodium Chlorate. The aim of the study was to determine the effects of the test item on the growth of Lemna minor over 7 days under static exposure conditions. On the basis of a preliminary test, 5 concentration levels were chosen in a geometrical series with a dilution factor of √1 0: nominal: 3.2 - 10 - 32 - 100 - 320 mg/L. Three replicates were investigated for the test concentrations and the control. Frond numbers were assessed on days 0, 2, 5 and 7. Inhibition of log biomass growth. specific growth rate and biomass dry weight were determined. The concentrations of sodium chlorate were analysed on day 0 (freshly prepared solutions) and on day 7 (old solutions) via HPLC. The recovery rates of the active ingredient chlorate were> 80 % at start and end of the study (for details of the analytical method and results please refer to chapter 10). Environmental parameters like water temperature and pH-value were determined to be within the acceptable limits. The effects of sodium chlorate, based on nominal concentrations, are summarised in table 1. Table 1: Effects on Lemna minor after 2, 5 and 7 d (based on nominal concentrations of the test item:    2d 5d  7d    Inhibition of log biomass growth [mg/L]          Elog bC50value  91.3 60.5 73.7  95 % confidence interval for ElogbC50values  68.6 -122  38.6 -95.0   34.5 -158  LOEC 100 100  32   NOEC 32  32  10  Inhibition of specific growth rate [mg/L]            ErC50value  91.3  57.8  134  95 % confidence interval for ErC50values  68.6 -122 35.8 -93.3  33.7 - >320   LOEC 100  100  32   NOEC 32  32  10  Inhibition of log biomass dry weight [mg/L]            ElogdwC50value n.a  n.a  128   95% cofidence interval forElogdwC50value n.a  n.a  28.0- >320   LOEC n.a  n.a  32   NOEC n.a  n.a  10  n.a. =not applicable

Validity criteria fulfilled:

yes