Carbamic acid, N-[(1R)-2-hydroxy-1-phenylethyl]-, 1,1-dimethylethyl ester

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:

4 AUGUST 2016 to 7 SEPTEMBER 2016

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Carbamic acid, N-[(1R)-2-hydroxy-1-phenylethyl]-, 1,1-dimethylethyl ester

EC Number:

600-273-1

Cas Number:

102089-74-7

Molecular formula:

C13H19NO3

IUPAC Name:

Carbamic acid, N-[(1R)-2-hydroxy-1-phenylethyl]-, 1,1-dimethylethyl ester

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Appearance: Powder
Aqueous solubility: 450 mg/L
Purity: 99.99%
Batch No: LS-53-20150815

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Details on test solutions:

The pre-cultivated algae were observed using microscopic to ensure the algae were in good condition. The biomass of pre-cultivated algae was 168.3x 10(4) cells/mL which counted by cell counting. The algal stock solution (100x10(4) cells/mL) was obtained by diluting 59.4mL of pre-cultivated algae to 100mL using growth medium.

Test organisms

Test organisms (species):

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

Details on test organisms:

Pseudokirchneriella subcapitata was the recommended species in OECD guideline 201. Purchased from Institute of Hydrobiology, Chinese Academy of Sciences, cultured and maintained in the lab. The sensitivity of the algae was checked periodically by determining the 72h-ErC50 of the reference item (Potassium dichromate) to algae. The ErC50 (72h) of Potassium dichromate to the alga (Pseudokirchneriella subcapitata) (batch No. LZ20160422001 (YJ)) was 1.267mg/L, with 95% confidence interval of 1.193mg/L to 1.350mg/L. It proved that the sensitivity of the alga (Pseudokirchneriella subcapitata) fulfilled the criteria.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

24h intervals

Test conditions

Test temperature:

23°C ± 2°C

pH:

7.8 - 9.2

Nominal and measured concentrations:

The test concentration of 25mg/L, 50mg/L, I 00mg/L, 200mg/L and 400mg/L were used in the definitive test based on the result of the preliminary test.The concentrations were in the 80-120% of the nominal.

Details on test conditions:

The solution of I 00mg/L, 200mg/L and 400mg/L were prepared as follow: 0.1003g, 0.2002g and 0.400 mg/L of test item were added directly to 1L growth medium, respectively. Then these solutions were mixed at the speed of 600 r/min using stirrers at 25°C for 24 hours. The rest test solutions were obtained by diluting 200mg/L. The algal test solution was obtained by making 0.7mL of algal stock solution (10x10'4 cells/mL) up to 100mL using test solution. Blank control was run simultaneously using growth medium. The control had six replicates and each concentration group had three. Each replicate had 100mL test solution. The measured initial cell concentrations in the test solution and control were approximately 0.8146x 10'4 cells/mL. The test was carried out in the full-temperature light shaking incubator. Spectrophotometer was used in this test to determine the algal biomass. The algal biomass in each flask was determined daily during the test period. Microscopic observation was performed to verify a normal and healthy appearance of the inoculum culture and to observe any abnormal appearance of the algal at the end of the test. Measure the pH of the solution at the beginning and at the end of the test. Concentrations of the test item were analyzed daily during the test.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

348.582 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The growth inhibition concentration was determined by probit using SPSS (Version.17.0). The result showed that the 72h-ErCs of N-Boe-D-phenylglycinol was 348.582mg/L, with the 95% confidence limits range from 286.192mg/L to 458.411mg/L. For estimation of the NOEC, for the effects of the test item on growth rate, the mean for each concentration was compared with the control mean using Dunnett's test by SPSS (Version.17.0). The NOEC ofN-Boc-D-phenylglycinol was 50mg/L.

Executive summary:

The     growth      inhibition      test      of     N-Boc-D-phenylglycinol      to      alga (Pseudokirchneriella subcapitata) was performed in this test. According to the  result of the preliminary test, the concentrations of definitive test  were 25mg/L,   50mg/L,   100mg/L,  200mg/L and 400mg/L.  The  solutions of 100mg/L,  200mg/L and 400mg/L were prepared as follow:  0.1003g,  0.2002g  and 0.400 mg/L of test  item  were added to 1L growth  medium, respectively.  Then  these solutions were mixed at the  speed of 600 r/min using stirrers at 25C  for 24 hours. The 25mg/L and 50mg/L test  solutions were obtained by diluting prepared 200mg/L test solution. The algal test solution  was obtained by making 0.7mL of algal stock solution (10010' cells/mL) up to  I00mL using test solution. Blank control was run simultaneously using growth medium. The control had six replicates and each concentration group had three.  Each replicate had 100mL test solution. The initial cell concentrations  in  the  test  solution  and  control  were  approximately  0.8146x10'4 cells/mL (measured value).  All  test  vessels were placed  in  the full-temperature light shaking incubator and then the incubation began.The test was carried out in the full-temperature light shaking incubator. Spectrophotometer was used in  this  test to determine the  algal  biomass. The algal biomass  in  each  flask  was determined daily during  the  test  period.  Microscopic observation was performed to verify a normal and healthy appearance of the inoculum culture and to observe any abnormal appearance of the algal at the end of the test. Measure the  pH  of  the  solution  at  the  beginning  and  at  the  end  of  the  test. Concentrations of the test item were analyzed daily during the test. According to the results,  the concentration of the test item  was remained within the range  80%-120% of nominal.  so analysis of the results  was based on nominal concentrations.  The 72h-ErC50  of N-Boc-D-phenylglycinol  is  348.582mg/L and the 95% confidence limits range from 286.192mg/L to 458.411 mg/L. The NOEC value is 50mg/L.