Subject Toxicity testing

Safety is assessed by subjecting the antioxidant to a series of animal toxicity tests, eg, oral, inhalation, eye, and skin tests. Mutagenicity tests are also carried out to determine possible or potential carcinogenicity. Stabilizers are being granulated and Hquid products are receiving greater acceptance to minimize the inhalation of dust and to improve flow characteristics. 

Fuller details of the methods used for toxicity testing, the interpretation of the result and their use in setting standards for industrial hygiene are given in the more specialised texts on the subject see Carson and Mumford (1988) and Lees (1996). 

Medicines Agency (EMEA) regulations, it is set a threshold safety value of 10 ng L and compounds whose PEC exceeds this quantity, have to be subjected to toxicity tests and can therefore, be considered as potential candidates to be included in monitoring programs [23]. 

So the animals used in the toxicity test, both treated and control animals, are subjected to extremely thorough medical monitoring, even to the point of sacrificing their lives so that the toxicologist can learn in minutest detail whether any of their tissues have been damaged. Obviously, there is no way such thorough information could ever be collected from any imaginable study of humans exposed to chemical substances. 

Para 25 Sanctions under a Voluntary Scheme While a voluntary scheme could have no formal legal sanctions, we think that the following measures might help, nevertheless, to ensure that new drugs were subject to adequate toxicity testing and clinical trials... 

D. Chemical Use Classes. This includes the toxicology aspects of the development of new chemicals for commercial use. In some of these use classes, toxicity, at least to some organisms, is a desirable trait in others, it is an undesirable side effect. Use classes are not composed entirely of synthetic chemicals many natural products are isolated and used for commercial and other purposes and must be subjected to the same toxicity testing as that required for synthetic chemicals. Examples of such natural products include the insecticide, pyrethrin, the clinical drug, digitalis, and the drug of abuse, cocaine. 

Subjecting all chemicals to all possible tests is logistically impossible, and the future of toxicity testing must lie in the development of techniques that will narrow the testing process so that highly toxic and relatively nontoxic compounds can be identified early and either banned or permitted unrestricted use without undue waste of time, funds, and human resources. These vital commodities could then be concentrated on compounds whose fate and effects are less predictable. 

Other tests can reveal effects indicative of potential reproductive toxicity. Examples include the dominant lethal test, fertility assessment by continuous breeding, repeated-dose toxicity testing, and cancer studies where the gonads are subjected to pathological examination. These tests, however, provide information only on effects after dosing adult animals and are therefore not addressed below. 

The fourth characteristic which could make a waste a hazardous waste is toxicity. To determine if a waste is a toxic hazardous waste, a representative sample of the material must be subjected to a test conducted in a certified laboratory. The test procedure used from the inception of the hazardous waste management program was the EP-Toxicity test. The new test procedure is the Toxicity Characteristic Leaching Procedure (TCLP). The TCLP is more aggressive than was the formerly used EP-Toxicity test for certain chemicals. Many industrial wastes which previously were not hazardous wastes may be considered hazardous waste when tested using the new procedure. 

---