Bore-Plate toxicity
SUMMARY
Test Substance : Bore- Plate
Test Species : Brown shrimp (Crangon crangon)
Test Type : Acute toxicity. 96 h LC 50
Test Conditions : Semi-static test conditions according to guidelines issued by the Ministry of Agriculture, Fisheries and Food, Burnham-on-Crouch, U. K.
Results
Test substance : Bore- Plate
96h LC50 95% confidence limits (mg/l)
(mg/l)
> 10000 -
There were no significant mortalities or other adverse reactions to exposure in 40 shrimp exposed to a test concentration of 10000 mg/l for a period of 96 hours.
INTRODUCTION
This report contains a description of the methods used and the results obtained during a study to investigate the acute toxicity of Bore-Plate to brown shrimp (Crangon crangon).
The study was commissioned by Drill Aid Ltd. and undertaken between 13 – 17 November 1989.
Dates of Protocol Approval
Study Director : 3 November 1989.
HRC Ltd. Management : 3 November 1989
Sponsor : 9 November 1989.
MATERIALS AND METHODS
Test Substance
Identification : Bore- Plate
Description : Black powder.
Purity : 100%.
Date of receipt : 8 November 1989.
Expiry : After December 1990.
Storage : In original container at room temperature.
Method of preparation : Direct dispersion in water.
Test Species
Name : Brown shrimp (Crangon crangon).
Source : P. Garnett, King’s Lynn, Norfolk.
Acclimatisation : Dates: 3-13 November 1989. (Stock received: 3 November 1989).
Temperature: 14 ± 1C.
Dissolved oxygen : >= 8.l mgO2/l.
Mortalities : 2.8%.
Mean length : 4.3 cm (SD = 0.5).
Mean weight : 1.61g (SD = 0.48).
Test Water
Synthetic sea water (Synthetica(R) ) at 32% S and aerated for at least 12 hours prior to use.
Exposure Conditions
Test vessels : Glass aquaria holding 40 1 of test media.
Experimental design : 1 test concentration in duplicate, plus 1 control; 40 animals per test concentration.
Method of initiation: Shrimp were placed in prepared test media.
Loading: 0.81 g bodyweight/litre
Photoperiod: 16 h light : 8 h dark
Temperature: 14 ± 1C
Aeration: Via two propeller stirrers
Test concentrations: 10000 mg/l in duplicate
Medium renewal: Daily
Duration of exposure: 96 hours
Criteria of death: Absence of (i) respiratory movement and (ii) response to physical stimulation
Records
All raw data and other documents generated at HRC during the course of this study, together with a copy of this final report, have been lodged in the HRC Archives, Huntingdon, England.
RESULTS
There were no significant mortalities or other adverse reactions to exposure in 40 shrimp exposed to a test concentration of 10000 mg/l for a period of 96 hours.
Time (h) LC50 (mg/l) 95% confidence limits (mg/l)
3 >10000* -
6 >10000 -
24 >10000 -
48 >10000 -
72 >10000 -
96 >10000 -
Concentration (mg/l) LT50 (h) 95% confidence limits (h)
10000* >96 -
* 10000 mg/l was the highest concentration employed in this test. It was considered unnecessary and unrealistic to test at concentrations in excess of 10000 mg/l. Good suspension of the test substance throughout the water column was achieved with the aid of the propeller stirrers fitted to each exposure vessel