SIPTU are to ballot of hospital support staff on strike action over job evaluations and incremental credit for interns which have not been implemented under the Lansdowne Road Agreement.
They also want the same concessions that were granted to other emergency department staff last year.
SIPTU divisional organiser Paul Bell says support workers should be entitled to frontline grades.
He said: "Our members are fully committed to winning fair and equal treatment in the workplace.
"The failure of the HSE and Department of Health to resolve our concerns has put our members in an intolerable and inequitable situation."
The union say these issues include a failure by management to adhere to the fully binding provisions of the Lansdowne Road Agreement and Haddington Road Agreement.
"The most crucial elements that have not been adhered to include the reintroduction of a job evaluation scheme and the application of incremental credit to interns", Mr Bell added.
Other issues include the granting of concessions by the HSE and the Department of Health to nurses working in emergency departments, which have not been extended to other workers.
The balloting is due to take place today, with the result expected to be announced on Monday February 13.