Does cement board contain asbestos

Older cement board may contain asbestos, and then it is properly called "asbestos cement board." Cement board more recently manufactured should not contain asbestos.

The only way to know whether a particular cement board does or does not contain asbestos is to ask the manufacturer (if you know who made it) or have a sample collected from it by a qualified sampling technician and have the sample analyzed by a qualified laboratory.