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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Nov. 1999-March 2000
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study done according to OECD guideline 201.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2000
Report Date:
2000

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
yes
Details on test solutions:
Acetone was used as a solvent (1 ml/l).

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Source (laboratory, culture collection): Ecotoxicology Dpt. of Centro Nacional de Sanidad Ambiental. Instituto de Salud Carlos lll 28220 . Majadahonda ( Madrid)

Study design

Total exposure duration:
72 h

Test conditions

Hardness:
(Ca + Mg)
Test temperature:
22 ± 1
pH:
7.1 ± 0.1
Nominal and measured concentrations:
The nominal concentrations tested were 25, 50 and 100 ug/l.
Measured conc. (ug/l) 23, 25, 98
Details on test conditions:
Initial cells density: 10^4
- Determination of cell concentrations: Coulter Counter
Triplicate vessels were used for test solutions and 2-5 for controls.

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
>= 50 µg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
100 µg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
100 µg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Details on results:
No effects were found for LAB C10-C13 at 50 ug/1 (solubility as measured in study for C12 LAB: 37.6 ug/l).
EC50 values were above 100 ug/l for all the tested substances.

Any other information on results incl. tables

TABLE ll

                             Cell concentrations for LAB CAS 67774-74-7

                             Time                 72 hours

                             Replicates          3

                             Controls             6

                             Nº                      104 cell/mL

                             Threshold           8

                             Cell Diameter     3.340 µm

                             Cell Volume      19.48  µm3

Controls

C - 1

C – 2

C – 3

C – 4

C – 5

C - 6

198

207

244

211

208

247

220

210

217

224

210

233

201

205

245

221

230

235

206

207

235

220

216

238

F = 2000                              `x = 220                 S = 13.6                                                                                         N = 4.4 x 105                        µ = 1.30

LAB – CAS  67774-74-7

¬

`x

­

`x

®

`x

267

281

259

`x = 269

25 ppb

273

278

261

269

268

260

N=5.4x105

294

265

254

µ = 1.33

288

292

254

`x= 272

50 ppb

277

278

292

288

237

250

`N=5.4x105

268

280

260

µ = 1.33

230

204

191

`x=216

100 ppb

259

245

206

206

191

198

N=4.3x105

245

209

211

µ = 1.25

TABLE lll

                             Cell concentrations for LAB C10

                             Time                 72 hours

                             Replicates         2

                             Controls            2

                             Nº                     104 cell/mL

                             Threshold          8

                             Cell Diameter    3.340 µm

                             Cell Volume      19.48 µm3

Controls

C-1

C-2

335

356

341

353

375

381

350

363

F = 2000                              x = 357                    S = 9.19                                                                                            N = 7.1 x 105                        µ = 1.42

LAB – C10

¬

`x

­

`x

212

267

x = 248

25 ppb

222

224

274

272

µ = 1.30

238

274

N=5x105

282

284

x= 254

50 ppb

229

256

234

252

µ = 1.30

258

238

N=5.1x105

261

183

x=230

100 ppb

228

245

239

215

µ = 1.27

248

223

N=4.6x105

TABLE IV

                             Cell concentrations for LAB –C12

                             Time                168 hours (prolonged)

                             Replicates          3

                             Controls             5

                             Nº                      104 cell/mL

                             Threshold           8

                             Cell Diameter     3.340 µm

                             Cell Volume      19.48  µm3

Controls

C-1

C-2

C-3

C-4

C-5

4033

2469

2251

3241

2551

4168

2499

2115

3309

2619

4347

2469

2243

3392

2661

4182

2479

2203

3314

2610

      Annuled           F = 2000                 ` x = 2651                  S = 573.12   

                                      N = 5.3x 106      µ = 0.89

LAB – C12

¬

`x

­

`x

®

`x

2357

2616

3359

x = 2802

25 ppb

2439

2440

2532

2609

3396

3359

N=5.6x106

2525

2679

3322

µ= 0.9

2378

2119

2235

x= 2313

50 ppb

2510

2432

2210

2223

2320

2285

N=4.6x106

2410

2341

2302

µ= 0.87

2562

3191

3196

x=2914

100 ppb

2452

2482

3188

3183

3069

3079

N=5.8x106

2432

3172

2973

µ= 0.9

TABLE IV

                             Cell concentrations for LAB –C12

                             Time                168 hours (prolonged)

                             Replicates          3

                             Controls             5

                             Nº                      104 cell/mL

                             Threshold           8

                             Cell Diameter     3.340 µm

                             Cell Volume      19.48  µm3

Controls

C-1

C-2

C-3

C-4

C-5

4033

2469

2251

3241

2551

4168

2499

2115

3309

2619

4347

2469

2243

3392

2661

4182

2479

2203

3314

2610

      Annuled           F = 2000                 ` x = 2651                  S = 573.12   

                                      N = 5.3x 106      µ = 0.89

LAB – C12

¬

`x

­

`x

®

`x

2357

2616

3359

x = 2802

25 ppb

2439

2440

2532

2609

3396

3359

N=5.6x106

2525

2679

3322

µ= 0.9

2378

2119

2235

x= 2313

50 ppb

2510

2432

2210

2223

2320

2285

N=4.6x106

2410

2341

2302

µ= 0.87

2562

3191

3196

x=2914

100 ppb

2452

2482

3188

3183

3069

3079

N=5.8x106

2432

3172

2973

µ= 0.9

TABLE V

                             Cell concentrations for LAB –C14

                             Time                72 hours

                             Replicates         3-2

                             Controls             5

                             Nº                      104 cell/mL

                             Threshold           8

                             Cell Diameter     3.340 µm

                             Cell Volume      19.48 µm3

Controls

C-1

C-2

C-3

C-4

C-5

785

620

726

721

739

784

708

669

793

784

716

678

649

786

756

761

668

681

766

760

F = 2000                              x = 727                   S =  48.38                                                                                          N = 1.45 x 106                     µ = 1.65

LAB – C14

¬

x

­

x

®

x

743

821

x = 779

25 ppb

717

717

859

842

N=1.5x106

692

847

µ= 1.6

741

750

x= 740

50 ppb

710

728

728

753

N=1.48x106

735

783

µ= 1.6

705

645

807

x= 719

100 ppb

719

718

611

620

854

819

N=1.4x106

740

604

798

µ= 1.6

TABLE VI

                                 Inhibition of growth rate

Sample : Commercial LAB  CAS Nº 67774-74-7

Concentration ppb

Inhibition %

25

- 2.3

50

- 2.3

100

3.8

TABLA VII

                                     Inhibition of growth rate

Samples:  LAB C10 , LAB-C12 , LAB-C14

Concentration ppb

Inhibition (%)

LAB –C10

LAB –C12

LAB –C14

25

8.4

-1.1

3.1

50

8.4

2.2

3.1

100

10.5

-1.1

3.1

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 72-hr EC50 values were > 100 ug/l for all substances tested. This is higher than the measured solubility limit for C12 LAB of 37.6 ug/L.
Executive summary:

This study examined the toxicity of linear alkyl benzenes to aquatic algae. Scenedesmus subspicatus was exposed to concentrations of 25, 50 and 100 ug/l of test substance for 72 hrs. During this time, readings of the growth rate were taken. Tests were also done on C10, C12, and C14 linear alkyl benzenes in addition to commercial LAB. The 72 -hr EC50 values for all substances was >100 ug/l, which is higher than the solubility limit for these substances (measured solubility limit for C12 LAB = 37.6 ug/l).