1. Nano-materials: Environmental and Health Impacts Chem Eng Progress: 104 (12), 37- 40, 2008.

2. Some Facts More than 500 consumer products containing nano-materials are on the market; Some examples: pesticides, genetically modified foods – uncertainties and concerns about health risks Need more research on related environmental, health and safety (EHS) issues; Need standard nomenclature on nanotechnology, standard reference materials for EHS testing, and standard methods and procedures for evaluating EHS impacts;

3. Some concerns Bad memories: CFC, PCB, asbestos, etc. Unknowns: ZnO/TiO2 nanoparticles in sunscreens; some research, yet no unanimous conclusion on penetration, cytotoxicity; Obtaining physiologically or environmentally relevant information for assessment is difficult; Suspect: carbon nanotube (next asbestos ?) some data showed similarity on health effect between these two chemicals;

4. Regulations May be regulated under existing legislation: EPA, OSHA, FDA, Consumer Product Safety Commission CPSC; (for USA) Example: EPA has laws: Toxic Substances Control Act (TSCT), Clean Air Act (CAA), Clean Water Act (CWA), etc; They released TSCT – inventory status of nanoscale substance – general approach; “molecular identity” – the deciding factor EPA: need risk assessment (to environment and human) before action; to date, most work are on LC50;

5. Nanoscale Richard Feynman: “at the atomic level, we have new kinds of forces, new kinds of possibilities, new kinds of effects” From microscale to nanoscale: increase in surface area/volume ratio (surface atom more active), improved delivery and transport properties in biomedical fields, appearance of quantum effect (e.g. size dependent optical property); Any unforeseen effects? Toxicity?

6. Precautionary Approach EPA: current practice – categorizing nano- materials as their bulk counterparts; Precautionary principle: If activity raises threats of harm to human and/or environment, precautionary measures should be taken. Uncertainty remains: Need more efforts!