The Submit Comments link visible at the top of Dashboard pages allows users to submit comments related to the chemical or page being viewed - as well as the user’s comment, any text selection the user has made, and the URL for the page are included in the information sent to EPA for context.
There is also a general Feedback option from the About menu:
This menu item takes the user to a general comment entry form for providing feedback about the Dashboard. The Comments item under the About menu lets the user review all comments submitted, rather than the chemical / page specific comments shown by the comments tab.