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 microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

yes

Remarks:

to prevent evaporation of the test substance the pH of the test substance reaction mixtures was not measured at the start of the incubation period, only at the end

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES
- Vapour pressure: not determined/ volatile substance
- Water solubility (under test conditions): few mg/L at 18°C

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

activated sludge of a predominantly domestic sewage

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

20.1 to 21.1 °C

pH:

6.9 to 7.6

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 34.8, 69.5, 139, 278.1, 556.2, 1112.3 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 250-ml and 1L Erlenmeyer flasks
- Type (delete if not applicable): closed with Teflon coated lids
- Material, size, headspace, fill volume: working volumes of 5 and 200 mL; incubation in a shaking water bath (100 rpm)

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: deionized water containing no more than 0.01 mg/L Cu

ACTIVATED SLUDGE:
- Origin: waste water treatment plant of Nieuwgraaf in Duiven, NL (predominantly domestic wastewater)
- Dry weight: 1.7 g/L

SYNTEHTIC SEWAGE FEED AND STOCKS:
- Amounts of substances in 1 liter of deionized water: 16g peptone, 11 g meat extract, 3 g urea, 0.7 g NaCl, 0.3g CaCl2, 0.2 g MgSO4.7H2O, 2.8 g K2HPO4
- Quantity added: 1.6 mL of synthetic sewage feed is added in a total volume of 50 mL and 6.4 mL in a total volume of 200 mL
- The test substance was added directly into the incubation vessels

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : respiration rate of the activated sludge

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Test concentrations: 0 (control), 34.8, 69.5, 139, 278.1, 556.2, 1112.3 mg/L

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol (quality: 98,9%)

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

736 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

3 h

Dose descriptor:

EC10

Effect conc.:

66 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

3 h

Dose descriptor:

other: EC20

Effect conc.:

150 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

3 h

Dose descriptor:

other: EC80

Effect conc.:

3 603 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Details on results:

The calculated respiration rates and inhibition percentages of Dipentene are presented in Table II and the results of the graphical probit analysis are shown in Figure 2.

Results with reference substance (positive control):

The calculated respiration rates and inhibition percentages of dichlorophenol are presented in Table I and the results of the graphical probit analysis are shown in Figure 1.

Table 1: Respiration rates of the activated sludge, inhibition percentages, and pH at various concentrations of 3,5-dichlorophenol after 3 hours contact time

Concentration mg/L	Activity mg O2/g.min	Inhibition%	pH Start test	pH end test	Temperature end test (°C)
Control	0.282	--	6.8	7.0	20.6
Control	0.253	--	6.8	7.0	20.3
Control*	0.276	--	6.8	7.1	20.9
Control*	0.259	--	6.8	7.1	21.1
1.5*	0.235	12	6.8	6.9	21.0
3.0	0.165	38	6.9	7.2	20.4
5.9	0.135	49	6.9	7.2	20.7
11.8	0.106	60	6.9	7.2	20.4
23.6	0.053	80	6.9	7.2	20.8
47.2	0.035	87	6.9	7.1	20.1

 * = Inhibition percentages at concentrations indicated by the asterisk are calculated with the controls indicated by the asterisk. Table 2: Respiration rates of the activated sludge, inhibition percentages and pH at various concentrations of Dipentene after 3 hours contact time

Concentration mg/L	Activity mg O2/g.min	Inhibition%	pH end test	Temperature end test (°C)
Control	0.359	--	7.3	20.3
Control	0.394	--	7.4	20.5
Control*	0.400	--	7.5	20.4
Control*	0.406	--	7.4	20.7
34.8	0.365	3	7.4	20.4
69.5	0.341	9	7.4	20.6
139.0	0.282	25	7.5	20.7
278.1	0.224	41	7.5	20.9
556.2	0.212	44	7.6	20.7
1112.3*	0.206	49	7.6	20.5

* = Inhibition percentages at concentrations indicated by the asterisk are calculated with the controls indicated by the asterisk

Validity criteria fulfilled:

yes

Remarks:

the control respiration rates were within 15% of each other; the EC50 of the reference compound was 7 mg/L

Conclusions:

The EC50 of gum turpentine oil for activated sludge after 3 hours contact time is 736 mg/L.
The EC10, EC20 and EC80 are 66, 150 and 3603 mg/L, respectively.

Executive summary:

In a 3 hour acute toxicity study, activated sludge were exposed to gum turpentine oil at nominal concentrations of 0 (control), 34.8, 69.5, 139, 278.1, 556.2, 1112.3 mg/L under static conditions in accordance with the OECD 209 guideline.

The EC₅₀  value based on respiration rate inhibition was 736 mg/L.

 

This toxicity study is classified as not harmful and satisfies with the guidelines requirements for activated sludge toxicity study.

Results Synopsis

 

Test Organism: Activated sludge (origin: wastewater treatment plant, predominantely domestic wastewater)

Test Type : static

 

3-hr EC₅₀: 736 mg a.i./L               

3-hr EC₁₀: 10 mg a.i./L                  

Endpoint(s) Effected: respiration rate inhibition

Description of key information

In a 3 hour acute toxicity study conducted according to OECD Guideline 209, activated sludge were exposed to GUM TURPENTINE OIL. 
The 3-hr EC50  value based on respiration rate inhibition was 736 mg/L..  
The 3-hr EC10  value based on respiration rate inhibition was 10 mg/L..                

Key value for chemical safety assessment

EC50 for microorganisms:

736 mg/L

EC10 or NOEC for microorganisms:

10 mg/L