Pentapotassium bis(peroxymonosulphate) bis(sulphate)

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: US EPA 850.5400, 1996 draft

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

2006

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Samples were taken at 0 and 96 h. Due to the high LOQ of 700 µg KMPS triple salt/L, samples from the highest concentrations and from stock solutions were taken only.

Vehicle:

no

Details on test solutions:

not indicated

Test organisms (species):

Skeletonema costatum

Details on test organisms:

TEST ORGANISM
- Species/strain: Marine diatom (Skeletonema costatum )
- Source: Department of Botany, University of Texas
- Method of cultivation: Cultures were prepared from stock culture and maintained at 20°C at 14 hours light

Test type:

static

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

not indicated

Hardness:

not indicated

Test temperature:

20±2°C

pH:

8.1

Dissolved oxygen:

Not reported

Salinity:

20 ± 3 ‰

Nominal and measured concentrations:

Initial concentrations of test substance: 0, 55.6, 111, 222, 444, 889, 1780 µg KMPS/L, corresponding to
0, 25, 50, 100, 200, 400, 800 µg KHSO5/L

Measured concentrations:
The highest concentration of the solutions was analysed:
0 h and 96 h: below LOQ (LOQ = 700 µg/L)

Concentrations of stock solution ranged from 88 to 100% of nominal.

More details are given in "Any other information on materials and methods incl. tables"

Details on test conditions:

TEST SYSTEM
- Volume of test vessels: 250 mL vessels containing 100 mL test solution
- Vessels were covered with foam stoppers
- Aeration: Test chambers were hand-swirled twice daily
- Initial cells density: 7.6 x 10^4 cells/mL
- Control end cells density: 155 x 10^4 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes, Saltwater algae nutrient medium (SWAM)

OTHER TEST CONDITIONS
- Adjustment of pH: Yes, pH adjusted to 8.1 using 0.1 N hydrochloric acid and 0.1 N sodium hydroxide
- Photoperiod: 14 h light
- Light intensity: 4105 - 4351 lux
- Salinity (for marine algae): 20 ± 3 ‰

EFFECT PARAMETERS MEASURED : cell number, inhibition of growth rate

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

111 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

444 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

96 h

Dose descriptor:

other: ErC50

Effect conc.:

556 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 511 - 600

Duration:

96 h

Dose descriptor:

other: ErC50

Effect conc.:

489 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 489 - 511

Details on results:

- Exponential growth in the control: No abnormal appearance of control algae was observed. The growth rate corresponded to the required range.

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

Statistics was performed with SAS software, the NOEC were determined using ANOVA and one-tailed Dunnett´s test.

Cell concentration data

Test-Substance Concentration (nominal)  [µg KMPS triple salt/L]	Cell concentrations (mean values) [cells /mL x 104]
	measured
	24 h	48 h	72 h	96 h	% inhibition 72 h	% inhibition 96 h
Control	25	54	127	155	-	-
55.6	22	55	117	150	5	6
111	23	48	112	174	12	5
222	15*	43	114	130	21	18
444	13*	31*	113	126	33	24
889	4.2*	4.8*	7.7*	7.2*	100	100
1780	3.8*	3.8*	8.7*	7.4*	100	100
Temperature [0C]	21.4-21.7	-	-	-	-	20.7-21.0
pH	8.1	-	-	-	-	7.9-8.8

An initial cell concentration of 7.6 x 104 wasincubated

* Statistically significant different from control (Dunnett´s test, p=0.05)

 

 

Growth rate data

Test-Substance Concentration (nominal)  [µg KMPS triple salt/L]	Mean growth rate [cells /mL/h]
	measured
	24 h	48 h	72 h	96 h	% inhibition 72 h	% inhibition 96 h
Control	0.048	0.040	0.039	0.031	-	-
55.6	0.044	0.041	0.038	0.031	3	0
111	0.047	0.038	0.037	0.032	5	-3
222	0.029*	0.036	0.038	0.029	3	6
444	0.023*	0.028*	0.038	0.029	3	6
889	0*	0*	0*	0*	100	100
1780	0*	0*	0.0018*	0*	95	100

 

 

* Statistically significant different from control (Dunnett´s test, p=0.05)

Area under the growth curve

Test-Substance Concentration (nominal)  [µg KMPS triple salt/L]	Mean area under the growth curve
	measured
	24 h	48 h	72 h	96 h	% inhibition 72 h	% inhibition 96 h
Control	205	960	2940	6140	-	-
55.6	169	902	2780	5790	5	6
111	189	862	2600	5850	12	5
222	92.8*	610*	2320*	5060*	21	18
444	68.8*	422*	1980*	4660*	33	24
889	0*	0*	0*	0*	100	100
1780	0*	0*	0*	0*	100	100

* Statistically significant different from control (Dunnett´s test, p=0.05)

 

 

Effect data as KMPS triple salt

-	96 h [µg/L]^1	95 % c.l.
EbC50	489	489-511
ErC50	556	511-600
NOEC biomass	111	-
NOEC growth	444	-

¹ effect data are based on nominal concentrations

Validity criteria fulfilled:

yes

Conclusions:

The study and the conclusions which are drawn from it fulfill the quality criteria (validity, reliability, repeatability).The ErC50 and EbC50 values were calculated to be 556 and 489 µg KMPS triple salt/L, respectively.

Executive summary:

Materials and methods

The acute toxicity of KMPS triple salt to the marine diatom was determined in a static dose-response 96-h test according to the US EPA guideline 850.5400, 1996.

 

Results and discussion

The analytical verification of stock solutions resulted in recoveries ranging from 88 100 % of nominal. The measured concentrations in the 1,780 µg KMPS triple salt/L treatment (corresponding to 800 µg KHSO5) at 0 and 96 hours were less than the LOQ, which was determined to be 700 µg KHSO5/L/. The results were based on nominal concencentrations.

NOEC  = 111 µg KMPS triple salt/L (biomass), 444 µg KMPS triple salt/L (growth rate)

ErC50 = 556 µg KMPS triple salt/L

EbC50 = 489 µg KMPS triple salt/L           

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2001-05-04 - 2001-12-11

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Triplicate samples were taken at 0 hours from stock solutions. Samples were not filtered, i.e. to remove algal cells before analysis.

Vehicle:

no

Details on test solutions:

not indicated

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Species/strain: Selenastrum capricornutum, Strain No. CCAP 278/4
- Source (laboratory, culture collection): Culture Collection of Algae & Protozoa, Institute of Freshwater Ecology, Cumbria, UK
- Method of cultivation: Sterile nutrient medium was inoculated from a master culture and cultured under continuous illumination (6000-10000 lux) at 23°C

Test type:

static

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

not indicated

Hardness:

not indicated

Test temperature:

23±1°C

pH:

6.9 – 7.1

Dissolved oxygen:

8.7 – 9.5

Salinity:

not indicated

Nominal and measured concentrations:

Nominal test solutions: 0.0625, 0.125, 0.25, 0.50, 1.0 mg/L

Nominal concentrations of stock solutions, which were analysed: 1.25, 2.5, 5.0, 10 mg/L
Measured concentrations of stock solutions: 1.3, 2.8, 5.3, 10 mg/L
More details are given in "Any other information on materials and methodes incl. tables"

Details on test conditions:

TEST SYSTEM
- Test vessels were loosely stoppered
- Size of the test vessels: 250 mL
- Aeration: by orbital shaker, oscillating at 140 cycles per minute
- Initial cells density: 10.000 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes, according to the guideline
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: no
- Photoperiod: 16 h photoperiod daily
- Light intensity and quality: 3600-4700 lux

EFFECT PARAMETERS MEASURED: growth inhibition and biomass

Reference substance (positive control):

no

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Duration:

72 h

Dose descriptor:

other: EbC50

Effect conc.:

0.97 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 0.87 - > 1.0

Key result

Duration:

72 h

Dose descriptor:

other: ErC50

Effect conc.:

> 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 0.0 - > 1.0

Duration:

96 h

Dose descriptor:

other: EbC50

Effect conc.:

1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 0.92 - > 1.0

Duration:

96 h

Dose descriptor:

other: ErC50

Effect conc.:

> 1 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Not determined

Details on results:

- Exponential growth in the control: yes
- Other effects: Regrowth was observed after 3 days when cultures previously exposed to 1.0 mg/L were placed in fresh medium. This indicates that
KMPS triple salt compound had an algistatic effect on algal growth at a concentration of 1.0 mg/L.

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

EC50 values calculated using logistic model (Ashton, 1972), 95% confidence limits estimated by likelihood ratio method (Williams, 1986)

Cell concentration data

Test-Substance Concentration (nominal) [mg/L]	Cell concentrations (mean values) [cells/mL]
	measured
	0 h	24 h	48 h	72 h	96 h
Control	16495	39881	134907	536167	1682000
0.0625	15460	37316	139713	569867	1661400
0.125	14629	36056	139040	571853	1900267
0.25	13459	34380	112883	499667	1676900
0.50	12630	34397	119847	541707	1728200
1.0	12046	29361	67633	229900	879000
Temperature [0C]	23	23	23	23	22
pH	7.5-7.6	-	-	-	7.4-7.6

 

 

Summary of effects on cell growth and biomass after 72 h

Nominal concentration (mg/L)	Area under curve 72 h	% inhibition	Growth rate 0-72 h	% inhibition
Control	9.6	-	0.048	-
0.0625	10	-5.4	0.050	(3.7)
0.125	10	-5.4	0.051	(5.4)
0.25	8.7	9.5	0.050	(3.8)
0.50	9.4	2.0	0.052	(8.1)
1.0	4.4	55	0.041	15

Figures in brackets denote negative inhibition, which indicate increase  in cell density compared to control

 

 

Summary of effects on cell growth and biomass after 96 h

Nominal concentration (mg/L)	Area under curve 72 h	% inhibition	Growth rate 0-72 h	% inhibition
Control	36	-	0.048	-
0.0625	37	-2.0	0.049	(1.2)
0.125	40	-10	0.051	(5.2)
0.25	35	3.7	0.050	(4.3)
0.50	36	-1.4	0.051	(6.4)
1.0	17	52	0.045	7.2

Figures in brackets denote negative inhibition, which indicate increase  in cell density compared to control

 

 

Effect data

-	72 h [mg/L]^1	95 % c.l.	96 h [mg/L]^1	95 % c.l.
EbC50	0.97	0.87->1.0	1.0	0.92->1.0
ErC50	>1.0	0.0->1.0	>1.0	n.d.
NOEC	0.50	-	0.50	-

¹effect data are based on nominal concentrations

Validity criteria fulfilled:

yes

Remarks:

(Factor of increase of cell numbers > 16; pH of control cultures remained within 1 unit; Concentration of test substance equal with or greater than 80% of initial concentration during test)

Conclusions:

The study and the conclusions which are drawn from it fulfill the quality criteria (validity, reliability, repeatability). The 72-h EC50 for algae was determined to be 0.97 (biomass) mg/L and >1.0 (growth rate). All results are expressed in terms of nominal concentration.

Executive summary:

Materials and methods

An acute toxicity test in algae was performed according to OECD 201 without deviations. The test system was static and Selenastrum capricornutum was used as test organism. Algae were exposed for 72 h to 5 different concentrations in order to derive an EC50.

 

Results

NOEC (72 hours) = 0.5 mg/L

EbC50 (72 hours) = 0.97 mg/L

ErC50(0-72 hours) > 1.0 mg/L

EbC50(96 hours) = 1.0 mg/L

ErC50 (0-96 hours) > 1.0 mg/L

Description of key information

The acute toxicity of KMPS triple salt to aquatic algae was tested in two key studies. One acute toxicity test was performed according to the EU Guideline C3 and to the OECD Guideline 201. The second test was performed according to the US EPA guideline 850.5400, 1996.

Key value for chemical safety assessment

EC50 for freshwater algae:

1 mg/L

EC50 for marine water algae:

0.556 mg/L

EC10 or NOEC for freshwater algae:

0.5 mg/L

EC10 or NOEC for marine water algae:

0.444 mg/L

Additional information

The acute toxicity tests in algae and diatoms were performed according to guideline OECD 201, without deviations.The test systems were static and Selenastrum capricornutum (freshwater) and Skeletonema costatum (marine) were used as test organisms.Algae and diatoms were exposed for 72 h to 5 different concentrations in order to derive EC50-values.

It is important to note that the marine test is likely to overestimate the toxicity to KMPS triple salt, because in salt water oxidation of KMPS triple salt generates chlorine from sodium chloride, increasing the biocidal activity of test solutions. Further, as results obtained from these exponential test systems cannot be used without logarithmic transformation, only growth rate ErC50-values are relevant (TGD, 2003). Based on the behaviour of KMPS triple salt in sea water and the marginal ErC50-values obtained, classification and labelling with Acute env. tox. cat. 1, H400, according to Regulation 1272/2008/EC (CLP), respectively, does not apply.