The Irish Penal Reform Trust says it's working to abolish solitary confinement for under 18s.
Following the review of a case involving 4 boys at Oberstown, the IPRT calling on the Government to introduce regulations governing the use of single separation.
Executive Director of the IPRT, Deirdre Malone says the practice causes significant harm to children in detention.
She said: "Over 50% of them are in care prior to detention, over 50% have a mental need, these are challenging children but they are also extremely vulernable children.
"This practice with segregation and seperation or solitary confinement needs to be minimised in the first instance and eradicated completely in the short term."