More than 32,000 teachers who qualified a decade or more ago must pass child-protection vetting checks by the Garda in the next year.
Until recently, only recently-recruited teachers and those moving schools have been required to obtain Garda clearance, which is administered by the Teaching Council.
However, legislation has now been commenced which provides a legal basis for the retrospective vetting of all registered teachers.
This means that thousands of teachers hired before 2006 – when vetting became mandatory for new applicants – face Garda checks for child-protection reasons.
Those affected are typically permanent teachers who have been in the same school for the past decade or more.
The council, the regulatory body for the profession, says vetting will take place over the coming year on a phased basis.
Any teachers who have not been vetted will receive a letter from the council shortly or over the coming months.
This letter will provide information on the vetting rules and the disclosures, if any that must be made in order to get or renew certification and lay deadlines by which applications must be made.
In addition to a check for criminal offences, Garda vetting involves a search of “soft information”.
According to the Department of Justice, this is “information other than criminal convictions held by the Garda that leads to a bona-fide belief that a person poses a threat to children or vulnerable persons”.
The council will start with those who have never been vetted. Once this is complete, there will be periodic revetting of all registered teachers on an ongoing basis.
Minister for Education Richard Bruton has said the move to vet all teachers is an "important milestone" in helping to ensure children are properly protected in the school environment.
Under new rules, a teacher will face a fitness-to-teach inquiry if information in a vetting disclosure indicates a risk of harm to a child or vulnerable adult.
The council may also seek a vetting disclosure for such an inquiry in cases where the nature of a complaint raises a child-protection concern.
In all, about 65 per cent of the 92,000 teachers registered with the council have been vetted, a figure which is steadily increasing over time.
Child protection groups have welcomed the move, but say vetting procedures in other areas still required attention.
Although creche and preschool staff have to be vetted, individual childminders and sole traders do not and campaigners say this is placing children at risk.
Separately, long-awaited hearings into complaints about serious misconduct and underperformance by teachers may take place by the end of this year.
The last remaining legal obstacle in the way of hearings was removed last year.
Under these changes, the council will have the power to remove a teacher from its register where it deems the person unfit to teach, including where this is for child-protection reasons.
The council will also be charged with investigating underperformance or conduct issues on foot of complaints from students, parents and teachers, among others.
Only issues “of sufficient gravity” will result in an inquiry. Those against whom decisions are made may be suspended from the register or receive a sanction of “advice, admonishment or censure”.
The fitness-to-teach hearings, which have been promised for well over a decade, will be held in public by default.
However, a witness or teacher who is the subject of the complaint may apply to have some or all of the hearing heard in private.