Roughly 50 people in the UK die of skin cancer each year after being exposed to the sun while at work.
Research found that almost 250 new cases of malignant melanoma are registered each year from people working outdoors in industries such as construction, agriculture and leisure and entertainment.
Experts also revealed that there's a "macho culture" in some part of the industry preventing workers from covering up.
A separate study, also commissioned by the Institution of Occupational Safety and Health (IOSH), looked at work attitudes to sun safety in the construction sector, and found that two-thirds of workers who spent an average of nearly seven hours a day thought they were not at risk or were unsure if they were.
More than half (59%) of those questioned reported having had sunburn - a major contributor to skin cancer - at least once in the last year.
Researchers also found there are shared misconceptions about the threat of ultraviolet radiation in climates like the UK's, as cloud cover does not give total protection from the sun.
The studies' findings are being published as part of IOSH's No Time To Lose campaign to beat work-related cancers, with businesses urged to develop "sun safety strategies" that include regular updates on the UV index from weather forecasts, minimising sun exposure in the middle of the day and asking employees to wear long-sleeved, loose-fitting tops and trousers.
While using high-factor sunscreen is helpful it should not be relied on as the only barrier to the harmful rays, employers are advised.
IOSH executive director of policy Shelley Frost said: "We've a clear picture for the UK now of the number of people diagnosed with or dying from skin cancer because of sun exposure at work.
"It's a terrible disease but with some simple measures we can ensure people who work outside are not exposed to the solar radiation that causes it.
"Work-related skin cancer is avoidable but businesses and their employees hold the key to beating it and today we are showing them how it can be done."