I want to know if its appropriate to do a research job which involves study of toxic chemicals on Animals? Since we are not allowed to harm animals unnecessarily, and this job requires us to test various toxicants given to animals for research.and there are high chances that animal will die or suffer upon which the test is being conducted! What is the Islamic Ruling on such type of Job?

If its really going to help humanity then it may be allowed but just for some business purpose or things like that it is not allowed.