CCPR/C/116/D/2233/2013 detention and the treatment of the authors in detention do not give rise to severe physical or mental suffering of the degree required to constitute treatment contrary to these provisions. Second, the system of mandatory immigration detention of unauthorized arrivals is not arbitrary per se and the individual detention of each of the authors is also not arbitrary as it is reasonable, necessary, proportionate, appropriate and justifiable in all of the circumstances. Third, the fact of protracted detention is not in and of itself sufficient to amount to treatment in violation of these articles. 6.12 The State party refutes the allegations that the conditions of detention amount to inhuman or degrading treatment. The authors have been placed in the form of accommodation assessed to be most appropriate to their circumstances. Two authors are in immigration residential housing, one is in immigration transit accommodation and two are in an immigration detention centre. These facilities are all operated by Serco, a private contractor, which is obliged to ensure that people in detention are treated equitably and fairly, with dignity and respect. The actions and behaviour of Serco staff are underpinned by a code of conduct. Serco also has in place policies and procedures that focus on the wellbeing of people in detention. 6.13 All persons in immigration detention are subject to regular placement reviews in respect of the conditions of detention. Regular reviews have occurred in each of the authors’ cases. Immigration detention is also subject to regular scrutiny from external and independent agencies, such as the Australian Human Rights Commission, the Office of the United Nations High Commissioner for Refugees and the Minister’s Council on Asylum Seekers and Detention. 6.14 The State party recognizes that persons in immigration detention, particularly irregular maritime arrivals who have been subjected to torture and trauma or have preexisting mental health issues, may be vulnerable to mental health deterioration, selfharming behaviour and suicide. Events such as the refusal of a visa application, uncertainty around one’s immigration status and time in detention can place additional stress on such persons. For this reason, such persons have access to health care and mental support services appropriate to their individual circumstances, and qualified health professionals conduct regular health assessments. 6.15 All people entering immigration detention have a mental health screening within 72 hours of their arrival in order to identify signs of mental illness and any previous exposure to torture and trauma. Additionally, they are regularly assessed medically, so emerging health concerns and mental health issues can be identified. Irrespective of these periodic assessments, in situations where concerns are raised about a person’s mental health, the individual will be referred for a prompt assessment. 6.16 All immigration detention facilities, including those in which the authors reside, have on-site primary-health-care services of a standard generally comparable to the health care available to the Australian community and take into account the diverse and potentially complex health-care needs of persons detained in such facilities. When required specialist medical treatment is not available on site, detainees are referred to off-site specialists. 6.17 In August 2010 the Government implemented three new mental health policies relating to persons in immigration detention facilities: Mental Health Screening for People in Immigration Detention; Identification and Support of People in Immigration Detention who are Survivors of Torture and Trauma; and the Psychological Support Program for the Prevention of Self-Harm in Immigration Detention. 6.18 A number of the authors have received specific treatment and support for their physical and mental health issues. All of the authors have had physical health issues, such as dental pain or ear infections, which have been treated. Furthermore, all of the authors have been regularly reviewed by the mental health team and have received, inter alia, 12