Exo-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl methacrylate

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

OECD 201, GLP, analytical monitoring.

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

(1984)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 850.5400 (Algal Toxicity, Tiers I and II) (January 2012)

Version / remarks:

(1996)

Qualifier:

equivalent or similar to guideline

Guideline:

other: JMAFF No. 700, 1039 and 1014 (1986)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on test solutions:

The test method was adapted to volatile substances since a significant loss of the test item from the test solutions by volatilization was possible
during preparation of these solutions and during the tests. Test vessels were sealed and 0.3 g/L of NaHCO3 and 6 mM of HEPES buffer were
added to LC reconstituted water (to prevent limitation of growth coming from CO2 depletion and therefore increasing pH).

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata
- Strain: CCAP 278/4
- Source: cultured at CIT, origin: Culture Collection of Algae and Protozoa, Institute of Freshwater Ecology, Far Sawrey, Ambleside, Cumbria,
LA22 OLP, UK
- Age of inoculum (at test initiation):
- Method of cultivation: the algae were cultured under sterile conditions and maintained at exponential growth rate by adding weekly aliquots of
algal culture to fresh reconstituted water samples.

ACCLIMATION
- Acclimation period: no data, alga were cultured at CIT
- Any deformed or abnormal cells observed: no data

Test type:

static

Limit test:

no

Total exposure duration:

96 h

Hardness:

34 mg/L as CaCO3

Test temperature:

22.2 to 24.4 °C

pH:

7.19 and 7.22 to 8.26 (7.24 to 8.25 for the control)

Nominal and measured concentrations:

Nominal concentrations: 0, 0.0156, 0.313, 0.625, 1.25, 2.5, 5 and 10 mg/L corresponding to
Measured concentrations: 0, below the limit of detection 0.0167, 0.0654, 0.116, 0.254, 0.516, 1.22 and 3.63 mg/L (geometric mean measured
concentrations, 96-hours value)

Details on test conditions:

TEST SYSTEM
- Test vessel: glass test vessels (250 mL Erlenmeyer flasks)
- Type: closed system
- Aeration: was not used during the test but the cultures were constantly agitated
- Initial cells density: The number of cells in solutions was calculated for each replicate at time 0 as 1 x 10E+4 cells/mL.
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: LC reconstituted water
- Hardness: 34 mg/L ± 17 mg/L as CaCO3
- pH: 7.5 ± 0.3

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: no adjustment of pH before addition of the algae
- Photoperiod: illumination was continuous
- Light intensity and quality: 6950 lux to 7660 lux

EFFECT PARAMETERS MEASURED:
- Determination of cell concentrations: with a Malassez cell counter

TEST CONCENTRATIONS
- Limit test
- Test concentrations: 5.0 and 10 mg/L (5 mg/L limit of solubility (LS))
- Range finding study
- Test concentrations: 0.005, 0.05, and 0.5 mg/L

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

2.66 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI: 2.30 - 3.16 mg/L

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

0.913 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95% CL: 0.798 - 1.05 mg/L

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

0.254 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

(< LOQ) based on both the growth rate and biomass

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.751 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

2.28 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.251 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Reported statistics and error estimates:

The EC50 values were calculated, using geometric mean measured concentrations, according to Probit analysis (i.e. Finney's method, published by E. Weber, combined with Bliss's method). The confidence interval limits were calculated statistically according to Fieller's method.

Definitive (EC50) test 96 -hour % inhibition

Nominal concentration [mg/L]	Measured concentration [mg/L]	Percentage inhibitiongrowth rate	Percentage inhibitionbio mass
0	0
0.0156	below the limit of detection (0.0167 mg/L)or below the LOQ (0.0500 mg/L)	2	6
0.313	0.0654	2	8
0.625	0.116	2	5
1.25	0.254	1	6
2.5	0.516	4	23
5.0	1.22	6	57
10	3.63	71	98

Variation coefficient of the control cell density at 96 -hours: 4.39%

Validity criteria fulfilled:

yes

Conclusions:

Under the experimental conditions of this study, the 72-hour ErC50 and the 72-hour EbC50 of Isobornyl Methacrylate (IBOMA; CAS RN 7534-94-3)
were 2.28 and 0.835 mg/L, respectively, and the 96-hour ErC50 and the 96-hour EbC50 were 2.66 and 0.913 mg/L, respectively, in a static test
system for Pseudokirchneriella subcapitata according to guideline OECD 201.
The NOEC was 0.251 mg/L at 72 hours and 0.254 mg/L at 96 hours based on both the specific growth rate data and biomass data.

Executive summary:

In a 96 hour acute toxicity study, the cultures of Pseudokirchneriella subcapitata strain no. CCAP 278/4 were exposed to Isobornyl methacrylate at nominal concentrations of 0, 0.0156, 0.313, 0.625, 1.25, 2.5, 5.0, and 10 mg/L corresponding to geometric mean measured concentrations (96 hour values) of 0, below the limit of detection 0.0167, 0.0654, 0.116, 0.254, 0.516, 1.22 and 3.63 mg/L under static conditions in accordance with the guideline OECD 201.  The ErC₅₀value based on growth rate was 2.66 mg/L and

EbC₅₀value based on bio mass was 0.913 mg/L after 96 hours, respectively.

g a.i./L, respectively. 

There were no compound related phytotoxic effects reported in the study.

 

This toxicity study is classified as acceptable and satisfies the guideline requirements for this acute algal toxicity study with Pseudokirchneriella subcapitata.

 

Results Synopsis

 

Test Organism: Pseudokirchneriella subcapitata

Test Type: Static

 

96-hr ErC₅₀: 2.66 mg a.i./L                       95% C.I.:  2.30 to 3.16 mg a.i./L

96-hr EbC₅₀: 0.913 mg a.i./L                 95% C.I.:  0.798 to 1.05 mg a.i./L}

96-hr NOEC: 0.254 mg a.i./L (<LOQ)     

Endpoint(s) Effected:  based on growth rate and biomass

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.

Description of key information

A reliable key study is available on algae:
An OECD 201 study on Pseudokirchneriella subcapitata gives an 96h-EC50 value of

2,66 mg/l and a 96h-NOEC of = 0.254 mg/l

Key value for chemical safety assessment

EC50 for freshwater algae:

2.66 mg/L

EC10 or NOEC for freshwater algae:

0.254 mg/L

Additional information

A reliable key study is available on algae: An OECD 201 study on Pseudokirchneriella subcapitata gives an 96h-EC50 value of 2.66 mg/l and a 96h-NOEC of = 0.254 mg/l