I searched old threads for an answer to this question but still need clarification. My husband is a landscaper and can provide me w/all the grass clippings I want but they've been chemically treated. I am wondering if I put those on a compost pile, not in a bin, will it get hot enough to cook the chemicals away? Will it still be considered organic?

the answers are no ,no and no.

I agree. Since we have no grass, we've always been dependent on the neighbor's grass clippings for composting. The first neighbor it turned out had his lawn sprayed for fleas every month. The second neighbor was fine, until he suddenly used Bandini Weed and Feed. All my vegies died, since I dried those grass clippings and used them as mulch. But there are chemicals that will not disappear even after composting. There was a problem in northern California with that, several years ago.

Best not to use them. The weed and feed products have 2,4D in them, which was one of the ingredients of Agent Orange. You don't want that stuff anywhere near your family!

The correct answer to that is it depends. What were the clippings treated with and how long ago? One herbicide "professional" landscapers can use is known to be potent forever and will kill plants that long apparently, but many do not cling to the grass clippings or disipate fairly quickly and the clippings can be used after a week since the last application. But this is one of those "it depends" questions and you need to know which products have been dumped on that grass.