Lasers used in nightclubs could damage dancers' sight, researchers have warned.
The National Radiological Protection Board said the beams used were strong enough to cause serious injuries.
It said the cost of laser equipment has fallen significantly, allowing smaller clubs and discos to use them.
The NPRB said such products often came with inadequate safety information and were use by people with no experience of laser safety.
The NRPB will issue its warning at the Health Protection Agency conference in Warwick on Monday.
Laser beams are usually moved around under programme control using a pair of small mirrors and can be made visible in the air by using smoke, fog or light rain.
The beams are often directed towards the audience, but it said there were health risks when they were projected straight at people's faces.
Most of the lasers used in entertainment displays are Class 3B or Class 4, strong enough to cause damage.
But even when the beam is not so intense, they can still dazzle, scientists warn.
The NRPB's Dr John O'Hagan will tell the conference: "Lasers have been used in the entertainment industry for about 30 years to support live and recorded music.
"But whereas historically the equipment needed to put on these displays was large, expensive and complex, we are now seeing compact, self-contained units being sold to people who have no experience of laser technology or, in particular, laser safety."
He added: "There are safety issues that need to be addressed by companies to ensure that the public are not at risk of injury.
Dr O'Hagan will warn people can often buy laser display products aimed at the small discos or nightclubs for home use.
He said: "These products often fail to comply with internationally agreed laser safety standards and are rarely supplied with adequate safety information for the user.
"The National Radiological Protection Board has developed systems for assessing laser displays to assist suppliers, operators and enforcing authorities."