Clioquinol

Endpoint summary

Additional information

Short-term toxicity to fish

No. of studies were reviewed for Short-term toxicity to fish from reliable sources having Klimisch rating 2 .

The summary of the results are presented below

 

Sr.No	Endpoint	Effect values	Basis for effect	Duration	Species	Sources
1	LC50	103.74 mg/L	Mortality	96 hrs.	Carassius auratus	Predicted data for Target Cas:130-26-7
2	LC50	10 mg/L	Mortality	24 hrs.	Ptychocheilus oregonensis	Publication data for Target Cas:130-26-7
3	LC50	10 mg/L	Behaviour	24 hrs.	Oncorhynchus kisutch	Publication data for Target Cas:130-26-7

 

 

Based on the studies summarized in the above table for the target substance clioquinol and the read across substance,the endpoint value was found to vary between lethal concentration between LC50 = 10 mg/L to 103 mg/L in a 24hr to 96 hrs.study on the basis of mortality effect. Based on the LC50 values, the substance may qualify for the aquatic classification .

Since the BCF value of clioquinol reported was not >= 500 as well as the substance was found to be rapidly degradable.Thus considering the value from CLP Criteria for aquatic classification of the substance , it is concluded that Clioquinol could not exhibit short term toxicity to fish

Long-term toxicity to fish

According to annex IX of column I , Long-term toxicity testing on fish need not to be conducted as it is already provided as part of Annex VIII requirements.Therefore this study was considered to be waived.

Short-term toxicity to aquatic invertebrates

The no observed effect concentration (NOEC) value of clioquinol in aquatic invertebrate (Daphnia magna) in a 48 hr study on the basis of intoxication effect was estimated to be 8.449671 mg/L.

Long-term toxicity to aquatic invertebrates

According to annex IX of column I ; Long-term toxicity testing on invertebrate (species : Daphnia) need not to be conducted as it is already provided as a part of Annex VII requirements.Therefore this study was considered to be waived.

Toxicity to aquatic algae and cyanobacteria

The no observed effect concentration (NOEC) value of clioquinol in aquatic algae (Pseudokirchnerella subcapitata) in a 96 hr study on the basis of biochemistry effect was estimated to be 4.034495 mg/L.

Toxicity to microorganisms

Weight of evidence studies reviewed for toxicity to microorganisms from reliable sources having Klimish rating 2.

 

The summary of the results are presented below

 

Sr.no	Endpoint	Effect concentration	Spicies	Effect	Source
1	MIC	6.25 mg/l	Mycobacterium tuberculosis	Growth inhibition	Antimicrobial Agents and Chemotherapy
2	IGC50	25.21514 mg/l	Tetrahymena pyriformis	Growth inhibition	SSS QSAR
3	IC50	589.2197 mg/l	Tetrahymena pyriformis	Growth inhibition	SSS QSAR

 

By applying weight of evidence approach to the target chemical clioquinol,toxicity to microorganism (Mycobacterium tuberculosis and tetrahymena pyriformis) in a 48 hrs to 8 days study on the basis of growth inhibition study was found to vary between MIC = 6.25 mg/l and IGC50 = 25.21514 mg/L to 589.21 mg/l .