Reaction mass of 1-methyl-4-(1-methylethyl)-7-oxabicyclo[2.2.1]heptane and cineole

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Justification for type of information:

1,8-cineole (source substance) is one of the main constituents of the registered substance (target substance).

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

204.06 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

recalculated value

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

128.54 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: yield

Remarks on result:

other: recalculated value

Results with reference substance (positive control):

- Results with reference substance valid: YesL

Reported statistics and error estimates:

- Statistical analysis was performed using software ToxRat® Professional.

ANALYTICAL RESULTS:

Samples taken from test concentrations (biotic and abiotic test) were analysed at the start and every day thereafter until the end of the test in order to

determine maintenance of actual concentrations. Chemical analyses revealed that test item levels found were stable. It should be noted that measured concentrations corresponding to the nominal concentrations of 10 to 39 mg test item.L-1 were below the LOQ (40 mg.L-1) and thus were considered

as non-GLP values. Nevertheless, these concentrations were reported in the present study report in order to demonstrate that test item levels were stable even at the lowest concentrations.

(see Tables 1 and 2 of the appended Analytical Report). Thus, since initial and final measured concentrations were comparable to their respective nominal concentration and that the concentration of the test item was satisfactorily maintained within ± 20% of the nominal concentration throughout the test, the results can be based on nominal values.

BIOLOGICAL RESULTS:

Based on the results of the range-finding test, the effect of the test item on Pseudokirchneriella subcapitata was tested in a definitive study using six concentrations spaced by a factor of approximately 1.97. (see table below and figure 1) show the cell densities recorded during the final test and indicate a clear concentration-response relationship.

	Replicate	Nominal concentration(mg test item.L^-1)
		Control	10	20	39	77	152	300
t=24h	1	2.4	2.8	3.2	2.4	2.0	1.2	0.4
	2	4.8	3.2	1.6	4.0	2.4	0.4	0.8
	3	2.8	3.6	3.6	1.6	2.8	0.8	0.4
	4	3.6
	5	2.8
	6	3.2
	Mean	3.3	3.2	2.8	2.7	2.4	0.8	0.5
	Std. Dev.	0.85	0.40	1.06	1.22	0.40	0.40	0.23
t=48h	1	16.4	15.2	16.4	12.4	15.6	6.0	0
	2	18.8	16.4	12.0	13.2	12.4	9.2	0.4
	3	19.2	12.8	13.2	14.4	12.0	10.0	0
	4	18.0
	5	16.0
	6	17.6
	Mean	17.7	14.8	13.9	13.3	13.3	8.4	0.1
	Std. Dev.	1.28	1.83	2.27	1.01	1.97	2.12	0.23
t=72h	1	57.2	57.6	40.8	52.4	47.2	26.0	1.2
	2	55.2	52.8	50.0	48.0	43.6	28.0	0.8
	3	56.4	55.2	52.0	48.4	44.8	27.6	0
	4	62.4
	5	58.0
	6	55.6
	Mean	57.5	55.2	47.6	49.6	45.2	27.2	0.7
	Std. Dev.	2.63	2.40	5.97	2.43	1.83	1.06	0.61

Validity criteria fulfilled:

yes

Remarks:

Cell density : 115-fold increase within 72 hours Coefficient of variation : Mean coefficient of variation for section-by-section = 25.2% / Coefficient of variation of average specific growth rates = 0.9%. Validity criteria were fulfilled in this study.

Conclusions:

The toxic effect of the test item 1,8-CINEOLE to the unicellular algal species Pseudokirchneriella subcapitata was investigated in a static test. Based on the nominal exposure concentrations and under the experimental conditions, the 72-hour EC50 for the parameters growth rate and yield were determined to be 204.06 mg test item.L-1 and 128.54 mg test item.L-1, respectively.
The 72-hour EC10 for growth rate was 139.98 mg L-1 and for yield was 53.64 mg.L-1.

Executive summary:

An algal toxicity study was performed on Pseudokirchneriella subcapitata with 1,8 -cineole in accordance with GLP and OECD Guideline OECD 201.

Algal cells were exposed to an aqueous solution of the test item at the required nominal test concentrations 10, 20, 39, 77, 152 and 300 mg test item.L-1. The inhibition of growth in relation to control cultures was determined over a test period of 72 hours, and thus over several algal

generations. The concentrations of the test item (with and without algae) were determined by chemical analyses at the start and every day thereafter until the end of the test.

The test item levels were found to be relatively stable throughout the test (within ± 20% of the initial concentration throughout the test). Thus, the results were based on the nominal exposure concentrations.

The toxic effect of the test item 1,8-CINEOLE to the unicellular algal species Pseudokirchneriella subcapitata was investigated in a static test. Based on the nominal exposure concentrations and under the experimental conditions, the 72-hour EC50 for the parameters growth rate and yield were determined to be 204.06 mg test item.L-1 and 128.54 mg test item.L-1, respectively.

The 72-hour EC10 for growth rate was 139.98 mg L-1 and for yield was 53.64 mg.L-1.

Description of key information

Based on data available on 1,4 -cineole, the inhibition of growth to algae of test item REACTION MASS OF 1,4 -CINEOLE AND 1,8 -CINEOLE is obtained: the 72-hour EC50 for the parameters growth rate and yield were determined to be 204.06 mg test item.L-1 and 128.54 mg test item.L-1, respectively.

Key value for chemical safety assessment

EC50 for freshwater algae:

128.54 mg/L

Additional information

An algal toxicity study was performed on Pseudokirchneriella subcapitata with 1,8 -cineole in accordance with GLP and OECD Guideline OECD 201.

Algal cells were exposed to an aqueous solution of the test item at the required nominal test concentrations 10, 20, 39, 77, 152 and 300 mg test item.L-1. The inhibition of growth in relation to control cultures was determined over a test period of 72 hours, and thus over several algal

generations. The concentrations of the test item (with and without algae) were determined by chemical analyses at the start and every day thereafter until the end of the test.

The test item levels were found to be relatively stable throughout the test (within ± 20% of the initial concentration throughout the test). Thus, the results were based on the nominal exposure concentrations.

The toxic effect of the test item 1,8-CINEOLE to the unicellular algal species Pseudokirchneriella subcapitata was investigated in a static test. Based on the nominal exposure concentrations and under the experimental conditions, the 72-hour EC50 for the parameters growth rate and yield were determined to be 204.06 mg test item.L-1 and 128.54 mg test item.L-1, respectively.

The 72-hour EC10 for growth rate was 139.98 mg L-1 and for yield was 53.64 mg.L-1.