Two schoolboys required hospital treatment for severe burns after using sunbeds without supervision.
The boys were taken to Stirling Royal Infirmary
The youngsters, aged 11 and 13, spent 24 minutes on the beds at an unmanned salon in Stirling.
The boys' parents called the police and environmental health officers at Stirling Council also investigated.
However, they said they could not take any action because the law does not ban under-16s from using the beds and the salon was unmanned.
The boys were treated for burns at Stirling Royal
Environmental health officer Anne McDonald said: "By the time the boys had finished, they had spent a total of 24 minutes on the sunbeds, resulting in them having some severe burns.
"Currently there is no legislation which bans young people under the age of 16 years from using a sunbed.
"This situation is recognised as being a loophole in the health and safety at work legislation.
"Therefore we couldn't take any action because the salon was unmanned."
She said under-16s were not allowed to use the beds at most responsible staffed salons.
Some let youngsters have access if they were accompanied by an adult.
Stirling's unmanned salons display health and safety
posters and signs which advise under-16s not to use the sunbeds.
Earlier this year, the Sunbed Association (UK), which claims to represent about a quarter of all sunbed salons, and Cancer Research UK joined forces to call for under-16s to be banned from using sunbeds.
Code of practice
They also said that coin-operated tanning salons should be shut down and that European guidelines for all other salons should be introduced.
At the time, Kathy Banks, secretary of the Sunbed Association, said: "As part of our code of practice under-16s are not allowed to use sunbeds.
"We know there are non-member operators out there who ignore some or, even worse, all safety guidelines.
"Customers need to be given proper advice and information about using sunbeds responsibly."
Both organisations were said to be in talks with the UK Government about the introduction of new guidelines.