I did the same for both PPG and Sherwin Williams as well...not a peep from PPG. SW replied stating they'd forwarded my questions on to a department that could better answer my questions, but no response since then. I may email that department directly later if I think about it.
Dear Joshua,
Thank you for visiting Sherwin-Williams on-line. We appreciate your inquiry.
Our Regulatory Department is best suited in helping you with your inquiry. I have sent your inquiry to them with a requested that they contact your directly concerning this matter. You may also reach them directly at the following:
msds_mail@sherwin.com or 1-216-566-2902
Thank you again for your inquiry. Please let me know if you have any other questions.