"New regulations which came into effect in 2009 set new minimum standards for rental properties and these were being introduced on a phased basis for properties that were let prior to 31st January 2009 but since the 1st February 2013 they now apply to all rental properties...
FIRE SAFETY REGULATIONS
Multi-unit dwellings (e.g. a house divided into flats) must contain a mains-wired smoke alarm, a fire blanket, emergency lighting in common areas and an emergency evacuation plan.
Rental units that do not form part of a multiple unit (e.g. a house) must have a fire blanket and either a mains-wired smoke alarm or at least two 10 year self-contained battery operated smoke alarms.
Check your property has smoke alarms. Fire extinguishers are not required by law in rental properties but are highly recommended.
Non-Compliance
The penalties for non-compliance with the Regulations is a fine of not exceeding 5,000 euro or imprisonment for a term not exceeding 6 months or both, and the fine for each day of a continuing offence is 400 euro."
Source : irishlandlord.com.
N.B. A carbon monoxide alarm is NOT a smoke-alarm