Certain boppy slipcovers have been recalled because the zipper can break causing a choking hazard and also contain excess amounts of lead.
Here's the link to the Boppy website, which explains the problem and how to determine if you have an affected product.

http://www.boppy.com/re/

Here is some more information I pulled from this website: http://www.cpsc.gov/cpscpub/prerel/prhtml08/08097.html

Slipcovers recalled due to a choking hazard were sold in three color combinations and have the following UPC and date codes found on the California Flammability Law tag. Slipcovers sold in clear vinyl packages are labeled Boppy® Luxe.

Slipcovers recalled due excessive levels of lead paint were sold in four colors and have the following UPC and date codes found on the care instructions label and on the exterior of the packaging. Slipcovers sold in display boxes are labeled Boppy® Soothing.

Consumers should stop using these products immediately and contact The Boppy Company for a free replacement product.