2,5-di-tert-butylhydroquinone

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes

Specific details on test material used for the study:

Name of Test Item : YAPOX 2245
Chemical Name (IUPAC) : 2,5-Di-tertiary butyl hydroquinone
CAS No. : 88-58-4
Physical Appearance (with colour) : White to light tan Crystalline powder
Batch No. : 20015011219
Purity (As per Certificate of Analysis) : 99.37%
Batch Produced by (Name and Address) : YASHO INDUSTRIES LIMITED Plot No. 2514/2515, Phase IV,G. I. D. C., Vapi - 396195, Gujarat,India
Date of Manufacture : June 2019
Date of Expiry : May 2021
Storage conditions : Ambient (21 to 29°C)
Test Item Code by Test Facility : D819-002

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The test item YAPOX 2245 is insoluble in the test medium reverse osmosis water (tap water) according to an internal method.
Therefore, individual WAFs was determined by adding the appropriate amount of test item to dilution water reverse osmosis water (tap water) at loading rates of (e.g.1.0, 10.0, 50.0, 75 and 100.0 mg/L). Each mixing vessel was filled to achieve minimal headspace given the constraints of the vessels and closed with foil-covered stoppers. The mixture was stirred using a magnetic stirrer at minimum of 100 RPM (the duration of mixing was 6 hours, selected based on WAF equilibration trail). Same method was employed during every renewal period.
The mixtures were allowed to settle and equilibrate to test temperature (before removing the test solution). The aqueous portions of WAFs were collected using steri- pipette and transferred to test vessels. Same method was employed for control group using reverse osmosis water (tap water).
The preparation of test media on day 0 during range finding study and main study are presented as Appendix 2 and Appendix 5 respectively.
During dose range finding study and main study TOC was analyzed on day 0 (fresh) and on day 1 (spent) sample from all the group.

Test organisms (species):

Cyprinus carpio

Details on test organisms:

Fish Species : Cyprinus carpio (Cyprinus carpio)
Justification for Selection of Species : Cyprinus carpio (common carp) is readily available species and has been historically shown to be a suitable model for acute toxicity studies. Moreover, it is recommended by OECD Test Guideline No. 203, and by other regulatory test guidelines.
Source of Supply : In-house maintained Cyprinus carpio (common carp) procured from Fisheries Research and Information Center (Inland), Hebbal, Bangalore, Karnataka, India.
Total Length of Fish : The length was measured a day prior to the exposure. The total length of fish used in the range finding study ranged from 2.9 to 3.9 cm and ranged from 2.9 to 3.6 cm during main study respectively.
No. of Groups and No. of Fish per Group : Six groups [1 control and 5 treatment groups] consisting of 7 fish in each group were used during the range finding study. Seven groups [1 control and 6 treatment groups] consisting of 7 fish in each group were used during the main study.

Acclimatization
Forty two and forty nine healthy fish were collected with an additional of 10 fish for acclimatization during the range finding study and main study respectively. Healthy fish were acclimatized for 7 days prior to test initiation both during range finding study and main study respectively. No mortality was observed during acclimatization period.
Fish were fed ad libitum daily with commercial feed pellets (Kijaro Grow). Feeding was stopped approximately 24 hour prior to commencement of the exposure to test item.
Water temperature during acclimatization was between 22.1 to 22.9oC during range finding study and 22.8 to 22.7°C during main study. Hardness of the water measured once during the period of acclimatization (at start) was 220 and 208 mg CaCO3/L during range finding study and main study respectively. Prior to acclimatization the glass aquaria was labeled for identification (study no., study code, no. of fish acclimatized, acclimatization start and acclimatization end date).

Test Vessels
Thoroughly cleaned rectangular glass aquaria having the water holding capacity of 50 liters were used as test vessels. The test vessels were labeled for identification (study no., test item code, study code, group no. and nominal loading rate, exposure start and exposure end dates) prior to experiment initiation.

Feeding
Fish were fed ad libitum daily with commercial feed pellets (Kijaro Grow) during acclimatization. Feeding was stopped approximately 24 hours prior to commencement of the exposure to test item.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Remarks on exposure duration:

light intensity (540-1000 lux) of 584.6 and 567.2 lux was maintained during dose range finding and main study respectively. A photoperiod of 12 hour light and 12 hour darkness. Any disturbance that may change the behavior of the fish was avoided.

Hardness:

Dose Range Finding Study 168 to 176 mg/L CaCO3
Main Study 172 to 176 mg/L CaCO3

Test temperature:

Dose Range Finding Study 22.1 to 22.9 deg C
Main Study 21.8 to 22.8

pH:

Dose Range Finding Study 7.10 to 7.22
Main Study 6.70 to 6.99

Dissolved oxygen:

Dose Range Finding Study 80.3 to 90.8
Main Study 78.0 to 91.8 %

Salinity:

-

Conductivity:

-

Nominal and measured concentrations:

The TOC analysis of the nominal loading rates during the main study is
0.4942, 0.2340, 0.3782, 0.3130, 0.2757 and 0.5489 on Day 0 (Fresh) and
0.4975, 0.2284, 0.3919, 0.3233, 0.2786 and 0.5870 mg at the nominal loading rates of 0.019, 0.043, 0.094, 0.207, 0.455 and 1.0 mg/L on Day 1 (Aged) respectively.

Reference substance (positive control):

not specified

Key result

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

0.19 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

Dose Range Finding Study
No clinical sign of toxicity were observed in control group during the 96 hour exposure period.
Clinical signs of loss of buoyancy control and hypoactivity were observed at 2 hour and continued up to 48 hours however clinical sign of loss of buoyancy control was continued up to 78 hours exposure period at the tested nominal loading rate of 1.0 mg/L.
Clinical signs of loss of buoyancy control and abnormal vertical orientation were observed at 2 hour and continued up to 5 hour, however clinical sign of loss of buoyancy control was continued up to 54 hours observation period and clinical sign of hypoactivity was observed at 2 hour and continued up to 30 hour observation period at the tested nominal loading rate of 10.0 mg/L.
Clinical signs of loss of buoyancy control and hypoactivity were observed at 2 hour observation however clinical sign of loss of buoyancy control was continued up to 5 hours observation period at the tested nominal loading rate of 50.0 mg/L.
Clinical signs of loss of buoyancy control and hypoactivity were observed at 2 hour observation period at the tested nominal loading rates of 75.0 mg/L.
Clinical sign of loss of buoyancy control was observed at 2 hour observation period at the tested nominal loading rates of 100.0 mg/L.
Percent mortalities 100.0% were observed at the tested nominal loading rates of 1.0, 10.0, 50.0, 75.0 and 100.0 mg/L. No mortalities were observed in the control group.

Main Study
Based on the results of dose range finding study, main was conducted at the nominal loading rates of 0.019, 0.043, 0.094, 0.207, 0.455 and 1.0 mg/L of YAPOX 2245 along with control group.
No clinical signs of toxicity were observed in the control group and at the nominal loading rate of 0.019 mg/L during the 96 hour exposure period.
Clinical sign of hypoactivity was observed at 24 hour and continued up to 96 hour observation period at the tested nominal loading rate of 0.043 mg/L.
Clinical sign of hypoactivity was observed at 2 hour and continued up to 96 hour observation period at the tested nominal loading rate of 0.094 mg/L.
Clinical signs of hypoactivity and abnormal vertical orientation were observed at 2 hour and continued up to 54 hour observation period however clinical sign of hypoactivity continued up to 96 hour exposure period at the tested nominal loading rate of 0.207 mg/L.
Clinical signs of hypoactivity and abnormal vertical orientation were observed at 2 hour and continued up to 96 hour exposure period at the tested nominal loading rate of 0.455 mg/L.

Clinical signs of hypoactivity and abnormal vertical orientation were observed at 2 hour and continued up to 30 hour observation period however clinical sign of hypoactivity was continued up to 54 hour observation period at the tested nominal loading rate of 1.0 mg/L.
Percent mortalities 14.3, 28.6, 57.1, 71.4 and 100.0% were observed at the tested nominal loading rates of 0.043, 0.094, 0.207, 0.455 and 1.0 mg/L. No mortalities were observed in the control group and at the nominal loading rate of 0.019 mg/L.

The 96 hours acute Median Lethal Loading rate (LL50) of YAPOX 2245 was evaluated by using the Probit analysis (Finney, 1971) and result was 0.19 mg/L with 95% confidence limits, lower limit of 0.16 mg/L and upper limit of 0.23 mg/L.

Sublethal observations / clinical signs:

 SUMMARY OF MORTALITY and 96 hour % mortality DURING DOSE range finding STUDY

 

Group	Nominal loading rates. (mg/L)	No. of Fish/ Group at Start	Mortality (No.) Observed at						96 hours Percent Mortality
			2 h (±30 Mins)	5 h (±2h)	24 h (±2h)	48 h (±2h)	72 h (±2h)	96 h (±2h)
G1	0.0	7	0	0	0	0	0	0	0
G2	1.0	7	1	2	1	1	1	1	100.0
G3	10.0	7	2	2	1	1	1	0	100.0
G4	50.0	7	3	3	1	0	0	0	100.0
G5	75.0	7	4	3	0	0	0	0	100.0
G6	100.0	7	5	2	0	0	0	0	100.0

    h: hour; Mins: minutes; %: Percentage:

SUMMARY OF MORTALITY and 96 hour % mortality DURING MAIN STUDY

Group	Nominal Loading Rates (mg/L)	No. of Fish/ Group at Start	Mortality (No.) Observed at						96 hours Percent Mortality
			2 h (±30 Mins)	5 h (±2h)	24 h (±2h)	48 h (±2h)	72 h (±2h)	96 h (±2h)
G1	0.0	7	0	0	0	0	0	0	0
G2	0.019	7	0	0	0	0	0	0	0
G3	0.043	7	0	0	0	1	0	0	14.3
G4	0.094	7	0	1	0	1	0	0	28.6
G5	0.207	7	1	1	1	0	1	0	57.1
G6	0.455	7	1	1	2	1	0	0	71.4
G7	1.0	7	2	2	1	1	1	0	100.0

    Mins: minutes;h: hour; %: percentage; -: Not applicable;

 

Validity criteria fulfilled:

yes

Conclusions:

The 96 hours acute median lethal loading rate (LL50) value of YAPOX 2245 on fresh water fish, Cyprinus carpio is 0.19 mg/L

Executive summary:

The test itemYAPOX 2245, was tested for acute toxicity on fish. The freshwater fish,Cyprinus carpiowas exposedover 96 hours to YAPOX 2245 to determine the 96 hours median lethal loading rate (LL₅₀).

Dose range finding study

Dose Range finding study was conducted with5 nominal loading rates of 1.0, 10.0, 50.0, 75.0 and 100.0 mg/L of YAPOX 2245along with control group. No clinical sign of toxicity was observed in the control group during the 96 hour exposure period. Clinical signs of loss of buoyancy control and hypoactivity were observed during the 96 hour exposure period at the tested nominal loading rate of 1.0 mg/L. Clinical signs of abnormal vertical orientation, loss of buoyancy control and hypoactivity were observed during the 72 hour exposure period at the nominal loading rate of 10.0 mg/L. Clinical signs of loss of buoyancy control and hypoactivity were observed during the 24 hour exposure period at the nominal loading rate of 50.0 mg/L. Clinical signs of loss of buoyancy control and hypoactivity were observed during the 5 hour exposure period at the nominal loading rate of 75.0 mg/L. Clinical sign of loss of buoyancy control was observed during the 5 hour exposure period at the nominal loading rate of 100.0 mg/L. Mortalities of 100.0% were observed at the tested nominal loading rates of 1.0,10.0, 50.0, 75.0 and 100.0 mg/L. No mortalities were observed in the control group.

Main study

Based on the results of dose range finding study, main study was conducted at the nominal loading rates of 0.019, 0.043, 0.094, 0.207, 0.455 and 1.0 mg/L of YAPOX 2245 along with control group. No clinical sign of toxicity was observed in the control group and at the nominal loading rate of 0.019 mg/L during the 96 hour exposure period. Clinical sign of hypoactivity was observed at the nominal loading rates of 0.043 and 0.094 mg/L during the 96 hour exposure period. Clinical sign of hypoactivity and abnormal vertical orientation were observed at the nominal loading rates of 0.207, 0.455 and 1.0 mg/L during the 96 hour exposure period. Mortalities 14.3, 28.6, 57.1, 71.4 and 100.0% were observed at the tested nominal loading rates of 0.043, 0.094, 0.207, 0.455 and 1.0 mg/L. No mortalities were observed in the control group and at the nominal loading rate of 0.019 mg/L.

TOC Analysis

The TOC analysis of the nominal loading rates during the main study is 0.4942, 0.2340, 0.3782, 0.3130, 0.2757 and 0.5489 Day 0 (Fresh) and 0.4975, 0.2284, 0.3919, 0.3233, 0.2786 and 0.5870 mg at the nominal loading rates of 0.019, 0.043, 0.094, 0.207, 0.455 and 1.0 mg/L on Day 1 (Aged) respectively.

Description of key information

The 96 hours acute median lethal loading rate (LL50) value on fresh water fish, Cyprinus carpio is 0.19 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.19 mg/L

Additional information

The test itemYAPOX 2245,was tested for acute toxicity on fish.The freshwater fish,Cyprinus carpiowas exposedover 96 hourstoYAPOX 2245to determine the 96 hours median lethal loading rate (LL₅₀).

Dose range finding study

Dose Range finding study was conducted with5 nominal loading rates of 1.0, 10.0, 50.0, 75.0 and 100.0 mg/L of YAPOX 2245along with control group.No clinical sign of toxicity was observed in the control group during the 96 hour exposure period.Clinical signs of loss of buoyancy control and hypoactivity were observed during the 96 hour exposure period at the tested nominal loading rate of 1.0 mg/L.Clinical signs of abnormal vertical orientation, loss of buoyancy control and hypoactivity were observed during the 72 hour exposure period at the nominal loading rate of 10.0 mg/L.Clinical signs of loss of buoyancy control and hypoactivity were observed during the 24 hour exposure period at the nominal loading rate of 50.0 mg/L.Clinical signs of loss of buoyancy control and hypoactivity were observed during the 5 hour exposure period at the nominal loading rate of 75.0 mg/L.Clinical sign of loss of buoyancy control was observed during the 5 hour exposure period at the nominal loading rate of 100.0 mg/L.Mortalities of 100.0% were observed at the tested nominal loading rates of 1.0,10.0, 50.0, 75.0 and 100.0 mg/L. No mortalities were observed in the control group.

Main study

Based on the results of dose range finding study, main study was conducted at the nominal loading rates of 0.019, 0.043, 0.094, 0.207, 0.455 and 1.0 mg/L of YAPOX 2245along with control group.No clinical sign of toxicity was observed in the control group and at the nominal loading rate of 0.019 mg/L during the 96 hour exposure period.Clinical sign of hypoactivity was observed at the nominal loading rates of 0.043 and 0.094 mg/L during the 96 hour exposure period.Clinical sign of hypoactivity and abnormal vertical orientation were observed at the nominal loading rates of 0.207, 0.455 and 1.0 mg/L during the 96 hour exposure period.Mortalities 14.3, 28.6, 57.1, 71.4 and 100.0% were observed at the tested nominal loading rates of 0.043, 0.094, 0.207, 0.455 and 1.0 mg/L. No mortalities were observed in the control group and at the nominal loading rate of 0.019 mg/L.

TOC Analysis

The TOC analysis of the nominal loading rates during the main study is 0.4942, 0.2340, 0.3782, 0.3130, 0.2757 and 0.5489 Day 0 (Fresh) and 0.4975, 0.2284, 0.3919, 0.3233, 0.2786 and 0.5870 mg at the nominal loading rates of 0.019, 0.043, 0.094, 0.207, 0.455 and 1.0 mg/L on Day 1 (Aged) respectively.