Looks like the first one linked is the one that doesn't have the CertiPure certification.
Maybe not a big deal to some, but to me this can to taken seriously.
This is copied from the "Questions" portion of Signature Sleep Amazon page.
Are there any formaldehyde, methylene chloride or PBDEs in the materials used?
A:
yes
Hanna Mirjam Eagle answered on April 10, 2014
A:
Yes and what a surprise it was to us later when we found out after we had Chemical sensitivity all of a sudden! Watch out!
MAG answered on May 5, 2015
I want you to be comfortable, but I also want to be, you know, alive.