Consumer products such as laser pens intended for use by consumers are regulated under The General Product Safety Regulations 2005. BIS is responsible for the legislation but it is enforced by Local Authority Trading Standards Services.
Under the rules, Trading Standards Officers have a range of powers available to them with regards enforcement of the legislation such as requirements to mark or to warn, or to issue withdrawal or recall notices. They also have the power to prosecute traders.
This is a well-established regime that has seen many hundreds of dangerous products taken off the market including laser pens.