this is sheila davis of the silicon valley toxics coalition. she developed the solar school counts that ranks manufacturers by the sustainability. we don't want to solve the climate problem at the expense of other important wire mental issues like hazardous waste issues or resource issues or chemical of a issues that are non toxic issues. and that, ah, pretty much ah, the problem. what's solar? so it is green. it's only green in one days, we want to make sure it's green throughout his life cycle. another problem is that depending on the type of solar cell lends manufacturer, hazardous materials like lads, cadmium, or arsenic can end up in the modules. but increasingly, there also alternatives, and one of the key components of finding safer alternatives is being able to perform, or they call an alternative chemical assessment. and luckily right now we have the capacity to do this. so yes, the chemicals needed to make solar cells are problematic. there really needs to be pressure on the industry to come up with alternatives and make the switch on