JT Eaton Kills Bedbugs Plus contains petroleum distillates, so it will have a slight odor. That should dissipate shortly after the product sprays and dries.
As long as JT Eaton Kills Bed Bugs Plus is applied according to the label instructions, it's safe. You will need to wait until the treated area is completely dry before you let your cat back in.
According to the manufacturer,1 can of JT Eaton Kills Bedbugs Plus will treat approximately 130 square feet.
The label does state the JT Eaton Kills Bedbugs Plus can be applied to the top, bottom and sides of mattress and box spring until damp, paying attention to tufts/seams. Allow to fully dry before using. You can take bed apart and spray joists also.