Find the article that contains the content you want to re-use, and navigate to that article's abstract page.
On the abstract page, look in the right-hand column under Article Tools, and click on Request Permissions.
You'll be taken to a RightsLink page, and at the bottom there's a drop-down menu where you can select the appropriate re-use option.
Next, you'll be asked for more information about who you are and how the article will be reproduced.
Last, click Continue to obtain a license to reproduce the content for the purposes you cited. You can print the license for your records from there.
If you need permission to re-use material from a SETAC book, please email your request to Jen Lynch. Be sure to include specific information about the content you plan to re-use, and the purpose of its re-use.