The on-going disturbances in Belfast over the decision of the city council to limit the flying of the Union flag now routinely see the Police Service of Northern Ireland deploy water cannon and baton rounds against protestors.

To be sure, these are hardly peaceful encounters, with 29 police officers injured in clashes over the last weekend. The police will feel justified in suspending Marquis of Queensbury rules and using the full range of tactics available to them to deal with such serious and persistent violence.

And yet, the thought of using baton rounds and water cannon in any other British city, or against, say, students, would be utterly unthinkable. But in most of the coverage of this dispute their regular tactical use merits little more than a passing remark.

Over the weekend, Sky News casually described baton rounds as "non-lethal". Yet history shows otherwise. The University of Ulster found that the use of such "non-lethal" weapons in policing the Troubles led to the deaths of 17 people, ten of whom were aged eighteen or under.

In fairness, there have been various attempts over four decades to come up with safer models. Rubber bullets, first used in Northern Ireland as long ago as August 1970, tended to ricochet wildly, injuring the unintended, often grievously.

They gave way to plastic bullets in the mid-1970s. However there were technical and reliability issues throughout the period of the Troubles before a new weapon, the L104A1 gun and the L21A1 baton round were deployed in 2001. This weapon boasted improved accuracy and safety over earlier versions, however the Defence Scientific Advisory Council still found that:

Users should be made aware that L21A1 baton rounds can ricochet in some circumstances with high energy, and that the presence of obstacles and of personnel other than the intended target should form part of their risk assessment in the decision to fire the weapon…

Yet the Omega Research Foundation (which specialises in evidence-based research into police and military technologies) was starker, describing it as "neither an accurate nor a safe weapon" in a major review. Nevertheless, the L21A1 rounds were defended by then policing minister Hazel Blears in 2004 on the basis that the risk of ricochet would be resolved by "police firearms training".

But in 2005 the Police Service of Northern Ireland began using a new weapon, the Attenuating Energy Projectile (AEP). This was deemed to be the safest option yet, with the projected round designed to collapse upon impact with a vulnerable area of the body, "reducing the probability of serious or life threatening injury", according to the Home Office’s Scientific Development Branch’s review of Less Lethal Technologies (note "less" not "non").

But the weapon is designed to be fired in a specific way. The AEP should be aimed to strike directly with the lower part of a target’s body (classed as below the rib cage). "Officers are trained to use the belt buckle area as the point of aim at all ranges, thus mitigating against upper body hits," says the report.

Yet Amnesty International and the Omega Research Foundation are less sanguine. Giving evidence to the Home Office Select Committee hearings into the summer 2011 riots (where there was a prospect of AEPs being used in Britain for the first time), they recommended that "further research and evaluation is undertaken into the AEP in order to better understand the associated injury pattern and risks."

However they are finessed, baton rounds require not only careful assessment of whether the target is a real threat to life, but also the selection of the correct part of the target’s anatomy. However accurately they are discharged (and assuming it is used by someone properly trained), there remains a potential to harm the individual struck or for the projectile to ricochet and hit other people.

Given the numbers of children involved in Northern Ireland’s street disputes, the concern must be that they can sustain more serious injuries than adults, given the relative size and vulnerability of their bodies.

A similar risk is inherent with using water cannon. As far back as 2002, the Defence Scientific Advisory Council’s Sub-Committee on the Medical Implications of Less Lethal Weapons recommended to the Northern Ireland Office that:

The impact of a high-pressure water jet from a water cannon is a high momentum event and may therefore lead to the displacement of the body. In certain scenarios (such as people close to solid obstacles), the potential for an increased risk of injury exists. Future guidance and training should reflect the risks arising from the displacement of people and objects.

Northern Ireland’s ‘otherness’ often sees different rules apply when it comes to policing and security, usually, it seems, for no better reason than that its legacy of fairly brutal practices has become normalised. It gives rise to the criticism that Northern Ireland has become a testing ground for such less-lethal weapons. Yet the regular use of baton rounds and water cannon against civilians, whatever their cause, within a corner of the British state is a dehumanising relic. Surely we can do better?