Editor’s note: since this post, developments have been made in the manufacturing and testing of encasements, and our recommendations have changed. Please read the Encasements page before deciding on an encasement.
As many readers know, many of us use National Allergy mattress encasements on our mattresses (and box springs, if we have them), and I am one of those. After many Bedbuggers had been using and recommending the encasements on this site for a long time, National Allergy offered Bedbugger readers a discount on all NA products, which you can access via this link or the National Allergy banner in the sidebar. (note: the discount is no longer offered so I have deleted the link)
The folks at National Allergy wrote recently to let me know they had done tests as to whether bed bugs could feed or pass through, or their eggs could pass through the fabric or the zippers of the mattress encasements, and I am happy to post them on the site for your perusal.
Click here to load a PDF of the report. The results begin on page 7.