Oxidation products of D-Glucose with nitric acid, sodium salts

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

yes

Remarks:

Chemical analysis was performed in a non-GLP laboratory

GLP compliance:

yes (incl. QA statement)

Remarks:

Chemical analysis was performed in a non-GLP laboratory

Specific details on test material used for the study:

- Source and lot/batch No. of test material: Rivertop Renewables, lot number 150330EAA
- Expiration date of the lot/batch: March 15, 2017
- Purity test date: Purity – 97.7%%
- Water solubility: 51.2%
- Physical state - Brown liquid

Analytical monitoring:

yes

Remarks:

Chemical analysis was performed in a non-GLP laboratory

Details on sampling:

Duplicate samples, approximately 10 to 15 mL from each replicate test or control vessel, were taken for analysis at the start (0 hours) and end (72 hours) of the exposure period. Samples were kept cool after sampling and were transferred to the analytical laboratory within 24 hours of sampling. Samples were analysed within apporximately 24 hours of sample reception.

Vehicle:

no

Details on test solutions:

All solutions of the test item were corrected for reported water solubility (i.e. 51.2% by weight in water). 781 mg of test material was weighed into a 500 mL volumetric flask and made up to volume with nutrient medium.

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata
- Source (laboratory, culture collection): University of Waterloo Culture Collection, CPCC 37
- Age of inoculum (at test initiation): 3 days and in exponential growth

ACCLIMATION
- Acclimation period: 3 days
- Culturing media and conditions (same as test or not): same
- Any deformed or abnormal cells observed: none reported

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Hardness:

Not applicable

Test temperature:

22°C

pH:

Range between 7.36 and 7.93

Dissolved oxygen:

Not applicable

Salinity:

Not applicable

Conductivity:

Not applicable

Nominal and measured concentrations:

Nominal exposure concentrations were 0 (control), 6.6, 14.8, 32.8, 72.9, 162, 360 and 800 mg/L.
Time weighted mean concentratinos were 0, less than limit of detection (nominal 6.6 and 14.8), 13, 30, 68, 147 and 333 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL Erlemeyer flasks
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 50 mL
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

GROWTH MEDIUM
- Standard medium used: yes

OTHER TEST CONDITIONS
- Sterile test conditions: no
- Adjustment of pH: no
- Photoperiod: constant

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: haemacytometer

Reference substance (positive control):

yes

Remarks:

Results are presented for sodium chloride and include 20 historical values.

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

169 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

60.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

68 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 333 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

141 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

30 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Results with reference substance (positive control):

Results are presented for sodium chloride and include 20 historical values.

Reported statistics and error estimates:

ANOVA/Dunnetts Multiple Comparion tests, Non-linear regression, Steel Many-One Rank Sum Test were performed using the CETISTM software

Analytical results, 0, 72 hour results and mean, <MDL = <6 mg/L

Control, <MDL, <MDL, na

6.6 mg/L, <MDL, <MDl, na

14.8 mg/L, <MDL, <MDL, na

32.8 mg/L, 14.3, 11.7, 13.0

72.9 mg/L, 34.1, 26.2, 30

162 mg/L, 78.1, 58.3, 68
360 mg/L, 181.9, 117.3, 147

800 mg/L, 400.6, 273.3, 333

Cell density results were as follows for 24, 48 and 72 hours,

Control - 5.25, 27.38, 139.0

6.6 mg/L - 4.38, 27.0, 156.75, inhibition -12.77%

14.8 mg/L - 4.13, 28.88, 152.0, inhibition -9.35%

32.8 mg/L - 3.63, 29.0, 132.38, inhibition - 4.77%

72.9 mg/L - 2.75, 25.25, 157.75, inhibition -13.49%

162 mg/L - 4.0, 25.38, 124.13, inhibition - 10.7%

360mg/L - 3.0, 17.63, 84.63, inhibition - 39.12%

800mg/L - 2.0, 6.63, 15.0, inhibition - 89.21%

Area under the growth curve results, 0 - 72 hours and % inhibition

Control, 1.73, -

6.6mg/L - 1.77, -2.29%
14.8 mg/L - 1.76, -1.68%
32.8 mg/L - 1.71, 0.96%
72.9 mg/L - 1.77, -2.37%
162 mg/L - 1.69, 2.19%
360 mg/L - 1.57, 9.58%
800 mg/L - 0.97, 43.83%

Yield results (x 10000 cells/ml), 72 hours and % inhibition

Control - 138.23, -
6.6 mg/L - 155.98, -12.84%
14.8 mg/L - 151.23, -9.40%
32.8 mg/L - 131.6, 4.79%
72.9 mg/L - 156.98, -13.57%
162 mg/L - 123.35, 10.76%
360 mg/L - 83.85, 39.34%
800 mg/L - 14.24, 89.71%

Validity criteria fulfilled:

yes

Conclusions:

Based on the reported information an acceptable assessment of toxicity to Pseudokirchneriella subcapitata was achieved. Based on the time weighted arithmetic mean concentrations of D-Glucose, reaction products with nitric acid and sodium nitrite (1:1), sodium salts the following results were obtained:
Biomass – 72 h EyC50– 169 mg/L, 72 h EyC10 – 60.7 mg/L, NOEC 68 mg/L
Growth rate - 72 h ErC50– >333 mg/L, 72 h ErC10 – 141 mg/L, NOEC 30 mg/L

Executive summary:

The effects of D-Glucose, reaction products with nitric acid and sodium nitrite (1:1), sodium salts to the algae Pseudokirchneriella subcapitata were determined in a 72 hour static study. The study was carried out according to OECD guideline 201. In this study algae were exposed to D-Glucose, reaction products with nitric acid and sodium nitrite (1:1), sodium salts over a test period of 72 hours in in a dose response study. Nominal concentrations were 0 (control), 6.6, 14.8, 32.8, 72.9, 162, 360 and 800 mg/L, corresponding time weighted arithmetic mean measured concentrations were 0, less than the limit of detection (6.6 and 14.8 mg/L), 13, 30, 68, 147 and 333mg/L.

Based on the time weighted arithmetic mean concentrations the following results were obtained:

Biomass – 72 h EyC50– 169 mg/L, 72 h EyC10 – 60.7 mg/L, NOEC 68 mg/L Growth rate - 72 h ErC50– >333 mg/L, 72 h ErC10 – 141 mg/L, NOEC 30 mg/L

Description of key information

The effects of D-Glucose, reaction products with nitric acid and sodium nitrite (1:1), sodium salts to the algae Pseudokirchneriella subcapitata were determined in a 72 hour static study. The study was carried out according to OECD guideline 201. In this study algae were exposed to D-Glucose, reaction products with nitric acid and sodium nitrite (1:1), sodium salts over a test period of 72 hours in in a dose response study. Nominal concentrations were 0 (control), 6.6, 14.8, 32.8, 72.9, 162, 360 and 800 mg/L, corresponding time weighted arithmetic mean measured concentrations were 0, less than the limit of detection (6.6 and 14.8 mg/L), 13, 30, 68, 147 and 333mg/L.

Based on the time weighted arithmetic mean concentrations the following results were obtained:

Biomass – 72 h EyC50– 169 mg/L, 72 h EyC10 – 60.7 mg/L, NOEC 68 mg/L Growth rate - 72 h ErC50– >333 mg/L, 72 h ErC10 – 141 mg/L, NOEC 30 mg/L

Key value for chemical safety assessment

EC50 for freshwater algae:

141 mg/L

EC10 or NOEC for freshwater algae:

30 mg/L