Chapter 3 Designing Safer Chemicals General Principles Methods for designing for Designing Safer Chemicals Safer chemicals 四大学化学学院 2002年7月26日
四川大学化学学院 2002年7月26日 1 General Principles for Designing Safer Chemicals Methods for Designing Safer Chemicals Chapter 3 Designing Safer Chemicals
3.1 General Principles for Designing Safer chemicals Two main ways to avoid Hazard and Toxicity 1: make it not possible to enter the body 2: make it not possible to affect the bio chemical and physiological processes(生物化学 和生理过程) hazardously. Direct hazard: to human beings, to environment Indirect hazard to human beings, to environment 四大学化学学院 2002年7月26日
四川大学化学学院 2002年7月26日 2 3.1 General Principles for Designing Safer Chemicals ◼ Two main ways to avoid Hazard and Toxicity ◼ 1：make it not possible to enter the body, ◼ 2：make it not possible to affect the biochemical and physiological processes(生物化学 和生理过程)hazardously. ◼ Direct hazard：to human beings, to environment ◼ Indirect hazard： ◼ to human beings, to environment
3.1.1: General Principles for Designing Safer Chemicals External considerations They refer to the reduction in exposure by designing chemicals that influence important physical and chemical properties related to environmental distribution and the up-take of the chemical by man and other living W organIsms 四大学化学学院 2002年7月26日
四川大学化学学院 2002年7月26日 3 3.1.1： General Principles for Designing Safer Chemicals ◼ They refer to the reduction in exposure by designing chemicals that influence important physical and chemical properties related to environmental distribution and the up-take of the chemical by man and other living organisms. External considerations
External considerations Structural designs or redesigns that will increase degradation rates and ■ those that reduce volatility(挥发 FE), persistence in the environment or conversion in the environment to biologically active substances represent examples of major external considerations for reducing exposur 四大学化学学院 2002年7月26日
四川大学化学学院 2002年7月26日 4 External considerations ◼ Structural designs or redesigns that will increase degradation rates and ◼ those that reduce volatility（挥发 性）, persistence in the environment or conversion in the environment to biologically active substances ◼ represent examples of major external considerations for reducing exposure
External considerations Molecular designs that reduce or impede(妨碍) absorption by man, animals and aquatic life (水生生物) also represent important external considerations 四大学化学学院 2002年7月26日
四川大学化学学院 2002年7月26日 5 External considerations ◼ Molecular designs that reduce or impede（妨碍） absorption by man, animals and aquatic life （水生生物） also represent important external considerations
External considerations Reduction of exposure or accessibility A Properties related to environmental distribution/dispersion 1. Volatility/density/melting point 2. Water solubility 3. Persistence/biodegradation a oxidation, b hydrolysis, C. microbial degradation 4. Conversion to biologically active substances 5. Conversion to biologically inactive substances 四大学化学学院 2002年7月26日
四川大学化学学院 2002年7月26日 6 External considerations------ Reduction of exposure or accessibility ◼ A. Properties related to environmental distribution/dispersion ◼ 1. Volatility/density/melting point ◼ 2. Water solubility ◼ 3. Persistence/biodegradation ◼ a. oxidation, b. hydrolysis, ◼ c. microbial degradation ◼ 4. Conversion to biologically active substances ◼ 5. Conversion to biologically inactive substances
External considerations Reduction of exposure or accessibility B Properties related to uptake by organisms 1. Volatility 2. Lipophilicity(亲油性) 3. Molecular size 4. Degradation a hydrolysis(水解),b. Effect of p C susceptibility to digestive enzymes (消化酶) 四大学化学学院 2002年7月26日
四川大学化学学院 2002年7月26日 7 External considerations------ Reduction of exposure or accessibility ◼ B. Properties related to uptake by organisms ◼ 1. Volatility ◼ 2. Lipophilicity（亲油性） ◼ 3. Molecular size ◼ 4. Degradation ◼ a. hydrolysis（水解）, b. Effect of pH, ◼ c. susceptibility to digestive enzymes （消化酶）
External considerations Reduction of exposure or accessibility C Consideration of routes of absorption by man animals or aquatic life 1.Skin/eves 2. Lungs 3. Gastrointestinal tract(消化系统) 4.Gills(#B)or other specific routes 四大学化学学院 2002年7月26日
四川大学化学学院 2002年7月26日 8 External considerations------ Reduction of exposure or accessibility ◼ C. Consideration of routes of absorption by man, animals or aquatic life ◼ 1. Skin/eyes ◼ 2. Lungs ◼ 3. Gastrointestinal tract（消化系统） ◼ 4. Gills(鳃) or other specific routes
External considerations Reduction of exposure or accessibility D. Reduction/elimination of impurities 1. Generation of impurities of different chemical classes 2. Presence of toxic homologs(同系物) 3. Presence of geometric, conformational or stereoisomers 四大学化学学院 2002年7月26日
四川大学化学学院 2002年7月26日 9 External considerations------ Reduction of exposure or accessibility ◼ D. Reduction/elimination of impurities ◼ 1. Generation of impurities of different chemical classes ◼ 2. Presence of toxic homologs（同系物） ◼ 3. Presence of geometric, conformational or stereoisomers
External considerations The routes of absorption include the following the skin, eyes, lungs, gastrointestinal tract ilIs or other routes depending on the organism 四大学化学学院 2002年7月26日 10
四川大学化学学院 2002年7月26日 10 External considerations ◼ The routes of absorption include the following: ◼ the skin, ◼ eyes, ◼ lungs, ◼ gastrointestinal tract, ◼ gills or ◼ other routes depending on the organism