Chapter3 Designing Safer Chemicals General Principles Methods for designing for designing Safer chemicals Safer chemicals
General Principles for Designing Safer Chemicals Methods for Designing Safer Chemicals Chapter 3 Designing Safer Chemicals
3 1 General Principles for Designing Safer chemicals
3.1 General Principles for Designing Safer Chemicals
3.1. General Principles for Designing Safer Chemicals .s Two main ways to avoid Hazard and Toxicity ss 1: make it not possible to enter the body, 2: make it not possible to affect the bio-chemical and physiologica/ processes(生物化学和生理过程 hazardously. . o to human beings, to environment Direct hazard indirect hazard
3.1.1 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. ❖ to human beings, to environment Direct hazard & Indirect hazard
General Principles for Designing Safer Chemicals External considerations Reduction of exposure or accessibility 减少化学品与生物机体接触的可能性 y Internal considerations Prevention of toxic effects n 预防化学品的毒性
General Principles for Designing Safer Chemicals ✓ External considerations： Reduction of exposure or accessibility 减少化学品与生物机体接触的可能性 ✓ Internal considerations： Prevention of toxic effects 预防化学品的毒性
General Principles for Designing Safer Chemicals External considerations so They refer to the reduction of exposure by designing chemicals to improve the important physical and chemical properties related to environmental distribution and the up-take of the chemicals by man and other living organisms
❖ They refer to the reduction of exposure by designing chemicals to improve the important physical and chemical properties related to environmental distribution and the up-take of the chemicals by man and other living organisms. External considerations： General Principles for Designing Safer Chemicals
External considerations A Properties related to environmental distribution/dispersion .s 1. volatility/density/melting point 2. Water solubility 令3. Persistence/ biodegradation(生物降解性 a. oxidation, b. hydrolysis, c. microbial degradation(微生物降解性 "s 4. Conversion to biologically active substances ,s 5. Conversion to biologically inactive substances
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 (生物降解性) a. oxidation, b. hydrolysis, c. microbial degradation（微生物降解性） ❖ 4. Conversion to biologically active substances ❖ 5. Conversion to biologically inactive substances
External considerations. Reduction of exposure or accessibility i . B Properties related to uptake by organisms 冷1. Volatility(挥发性) 小2. Lipophilicity(亲油性) & 3 Molecular size 4. Degradation(摩解性) a. hydrolysis(水解),b. Effect of ph C susceptibility to digestive enzymes a3 (敏感性) (消化酶)
❖ B. Properties related to uptake by organisms ❖ 1. Volatility （挥发性） ❖ 2. Lipophilicity（亲油性） ❖ 3. Molecular size ❖ 4. Degradation （降解性） a. hydrolysis（水解）, b. Effect of pH, c. susceptibility to digestive enzymes （敏感性） （消化酶） External considerations: Reduction of exposure or accessibility
External considerations Structural designs or redesigns ncrease degradation rates, reduce volatility(挥发 f), reduce persistence time in the environment and possibility of conversion to biologically active substances in the environment Molecular designs: reduce or impede(妨得) absorption by man animals and aquatic life(水生生物).B
❖ Structural designs or redesigns: increase degradation rates, reduce volatility（挥发 性）, reduce persistence time in the environment and possibility of conversion to biologically active substances in the environment. External considerations ❖ Molecular designs : reduce or impede（妨碍） absorption by man, animals and aquatic life（水生生物）
External considerations. Reduction of exposure or accessibility i . C. Consideration of routes of absorption by man animals or aquatic life o 1. skin/eyes 2. Lungs 3. Gastrointestinal tract(消化系统) *4.Gills(5) or other specific routes
❖ 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
External considerations. Reduction of exposure or accessibility 今B0 accumulation(生物聚集)0r Bio- magnificati0n(生物放大): It refers to the increase of tissue concentration of a chemical as it progresses up the food chain 生物放大:指食物链向上一级进展,化学物质在 组织中的浓度增大的现象
❖ Bio-accumulation（生物聚集）or Bio-magnification （生物放大）: ❖ It refers to the increase of tissue concentration of a chemical as it progresses up the food chain. ❖ 生物放大：指食物链向上一级进展，化学物质在 组织中的浓度增大的现象。 External considerations: Reduction of exposure or accessibility