Gum turpentine oil, consisting of the volatile fraction resulting from the distillation of oleoresin collected by tapping softwoods from pinacea derivatives (genus: pinus). It consists of terpenes, mainly monoterpenes such as alpha-pinene and beta-pinene.

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:

Crude sulfate turpentine is a UVCB substance that contains the same main constituents as gum turpentine oil. Therefore, data on crude sulfate turpentine can be extrapolated to gum turpentine oil. See read-across justification document in section 13.

Reason / purpose for cross-reference:

read-across source

Post exposure observation period:

None

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

17.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Water Accommodated Fractions (WAFs)

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

16.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Water Accommodated Fractions (WAFs)

Basis for effect:

biomass

Remarks:

(yield)

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Water Accommodated Fractions (WAFs)

Basis for effect:

other: growth rate and biomass (yield)

Details on results:

- Exponential growth in the control: yes, the cell concentration in the control cultures increased by a factor of 230 in 72 h.

- Effect concentrations exceeding solubility of substance in test medium: the loading rates at which the water-accommodated fractions were prepared exceeded the solubility of the test substance.

Reported statistics and error estimates:

The results of the Alga Test were analysed statistically with reference to the specific growth rate [µ] and biomass (yield).

Normality of the data was tested using a Kolmogorov-Smirnov-test (α = 0.05).

Homogeneity of variances was tested by Bartlett`s test (α = 0.05).

For all measured end values, statistical differences among treatment groups were determined using a one-way analysis of variance (ANOVA).

Two-sided Dunnet's procedure for multiple comparison was used to determine, which concentration of the test item differed significantly from the control (p = 0.05).

The results of the two-sided Dunnet's test (p = 0.05) were used to determine the NOELR (No Observable Effect Loading Rate) of the specific growth rate [µ] and of the biomass (yield).

The NOELR (No Observable Effect Loading Rate) is defined as the highest test loading rate, where inhibition of the specific growth rate [µ] and of the biomass was statistically not significantly different when compared to the control.

Table 1. Test results – average specific growth rates (µ) over the test period 0-72 hours

Loading rate [mg/L]	Cells / mL	Average Specific growth rate [µ]	Average Specific growth rate [µ] Mean value	Standard deviation	Coefficient of variation Vc [%]	Inhibition of Average Specific growth rate [%]	Inhibition of Average Specific growth rate Mean value [%]
Control 1	576000	1.81	1.81	0.00	0.15
Control 2	568000	1.81
Control 3	576000	1.81
5.0	584000	1.82	1.81	0.01	0.45	-0.34	-0.08
5.0	560000	1.80				0.43
5.0	584000	1.82				-0.34
10	568000	1.81	1.80	0.01	0.68	0.17	0.79
10	528000	1.78				1.52
10	552000	1.80				0.70
25	5000	0.23	0.15	0.09	57.1	87.3	91.8
25	3000	0.06				96.7
25	4000	0.16				91.4
50	4500	0.20	0.10	0.10	95.7	89.2	94.3
50	2500	0.00				100
50	3500	0.11				93.8
100	3000	0.06	0.09	0.06	59.7	96.7	94.9
100	3000	0.06				96.7
100	4000	0.16				91.4

 Remark: A negative inhibition value means an enhancement of the parameter.

Table 2. Test results – biomass (yield) over the whole test period 0-72 hours

Loading rate [mg/L]	Cells/mL	Yield Cells/mL	Yield Cells/mL Mean value	Standard deviation	Coefficient of variation Vc [%]	Inhibition of Yield [%]	Inhibition of Yield [%] Average
Control 1	576000	573500	570833	4619	0.81
Control 2	568000	565500
Control 3	576000	573500
5.0	584000	581500	573500	13856	2.42	-1.87	-0.47
5.0	560000	557500				2.34
5.0	584000	581500				-1.87
10	568000	565500	546833	20133	3.68	0.93	4.20
10	528000	525500				7.94
10	552000	549500				3.74
25	5000	2500	1500	1000	66.7	99.6	99.7
25	3000	500				99.9
25	4000	1500				99.7
50	4500	2000	1000	1000	100	99.7	99.8
50	2500	0				100
50	3500	1000				99.8
100	3000	500	833	577	69.3	99.9	99.9
100	3000	500				99.9
100	4000	1500				99.7

 Remark: A negative inhibition value means an enhancement of the parameter.

Table 3. Results of TOC analysis of the test media

Time [h]	Control	5.0 mg/L	25 mg/L	100 mg/L
0	0.3	0.3	1.7	4.7
72	≤0.3	0.1	1.2	3.8

 

Table 4. Results of GC-MS analysis of test media

Vessel	Time [h]	a-Terpineol [µg/L]	a-Pinene [µg/L]	b-Pinene [µg/L]	3-Carene [µg/L]	Limonene [µg/L]	Total [µg/L]
Control	0	0.214**	< 0.367*	0.227**	< 0.151*	0.212**	< 1.17
Control	72	0.214**	< 0.367*	0.227**	< 0.151*	0.212**	< 1.17
5.0 mg/L	0	5.81	94.1	10.1	23.2	9.12	142
5.0 mg/L	72	3.76	11.1	2.32	7.12	2.82	27.1
25 mg/L	0	37.6	735	75.3	222	96.1	1166
25 mg/L	72	22.5	116	22.8	84.5	38.4	285
100 mg/L	0	125	1111	116	243	113	1708
100 mg/L	72	104	173	32.7	81.6	41.5	432

Remarks:

*   Limit of detection

**   derived from equation of the calibration line (axis intercept); no signal was measured in the controls for α-Terpineol, β-Pinene and Limonene

         Quantitative GC-MS-values are based on results and/or limits of detection

Validity criteria fulfilled:

yes

Conclusions:

A 72h EL50 of 17.1 mg/L and NOELr of 10 mg/L have been determined for the effect of the test substance on growth rate of Desmodesmus subspicatus.

Executive summary:

An algal toxicity study was performed in accordance with OECD guideline 201 and GLP. Algal cells (Desmodesmus subspicatus) were exposed to Water Accommodated Fractions (WAFs) of the test item, over a range of nominal loading values of 5, 10, 25, 50 and 100 mg/L. The inhibition of growth in relation to control cultures was determined over a test period of 72 h, and thus several algal generations, in closed test vessels.

The EL50 and NOELr at 72 h for the test item to algae (Desmodesmus subspicatus) based on the nominal loading rates were determined to be 17.1 and 10 mg/L, respectively.

Description of key information

A 72-h EL50 of 17.1 mg/L and a NOELR of 10 mg/L have been determined for the effect of Crude Sulfate Turpentine on growth rate of Desmodesmus subspicatus.

Key value for chemical safety assessment

EC50 for freshwater algae:

17.1 mg/L

EC10 or NOEC for freshwater algae:

10 mg/L