Or they could even face up to 6 months in prison.
People are now required by law to wear a face-covering on public transport in Ireland from today.
Those who board public transport without a mask run the risk of being fined 2,500 euro or face six-months in prison.
Guidance was issued last night to Gardaí and operators on the new law, with unions saying their members are not trained in making sure people wear a covering.
Antoinette Cunningham from the Association of Garda Sergeants and Inspectors says it's been made clear who should enforce it.
''We're the second of the enforcement of this not the first line'', she said.
''The first line is the bus driver and train operators, if we are called to assist and having seen that the relevant person can't get the enforcement going, we'll go back to the graduated policing response we've had right throughout Covid''.
