EU legislation: Under new legislation being considered in the EU, Irish employers would be responsible for checking daily radiation levels to ensure their employees are not over-exposed to the sun.
The rules have been criticised by politicians and lobby groups, including the employers group, IBEC, as being too stringent and unworkable.
Known as the optical radiation directive and already quite far advanced in the European Parliament, the law would mean employers of staff working outdoors would have to examine everyday levels of radiation to see if their workers were at risk.
If the risk levels were too high, they would have to draw up an action plan to protect their workers.
The legislation would affect all those involved in outside work, which could include builders, rooftop workers, postmen, gardeners or catering staff.
The crucial clause in the directive, which deals with all forms of optical radiation including exposure to ultraviolet light and lasers, refers to radiation from "natural sources of radiation" - meaning sunlight.
Critics of the directive say its scope is far too wide reaching.
IBEC assistant director Tony Briscoe said the directive was "overkill" and asked how could employers differentiate if workers protected themselves during work but did not choose to do so after work.
He added that general duties for employers for protecting their employees existed under a law dating back to 1989 and IBEC had already had experience of advising businesses on protection of their outdoor staff.
"The question is do we need more regulation, I think that most employers would say no."
Mr Briscoe also said checking radiation levels did not simply involve going outdoors and looking up at the sky.
"My knowledge of the science is that it is a little more problematic than just deciding if it's a sunny day," he said.
Others warned that it would make employers liable for sun-related illnesses.
British Conservative MEP Philip Bushill-Matthews said "employers would potentially have a liability for skin cancer of an employee at any stage of their lives" while Fianna Fáil MEP Brian Crowley said that workers should be protected "but imposing unrealistic regulations at EU level for testing naturally occurring phenomena is the wrong approach to take".
The Brussels-based lobby for small and medium sized enterprises has also criticised the directive.
According to Oliver Loebel from the European Association of craft, small and medium-sized enterprises: "It is impracticable to expect a small construction or catering firm to make daily assessments on the potential health impact of the forecast meteorological conditions on their employees.
"It could also create a great degree of uncertainty about the legal liability in the case of diseases caused, in part, by exposure to natural sources of radiation."
The MEP in charge of parliament's position on the directive, centre-right Hungarian Csaba Ory, is assessing the implications.
An emergency meeting was held last week between the European Commission, Council and Parliament to discuss the situation, but the commission argued in favour of keeping the clause.
Defending the legislation, Mr Ory said it could "be very easily documented" whether employers had warned their employees about too high radiation levels.
The legislation must still be voted on in committee, coming before the parliament next month.