Risk and threat assessment
The threat of attack and physical violence to frontline staff such as, military personnel, customs and immigration officers, police and law enforcement officers, surveillance and intelligence officers, close protection officers, and security personnel has never been greater.
The selection of body armour commences with a risk analysis and threat assessment, including:
The weaponry likely to be used by attackers.
The probable strength and ferocity of the potential attack.
The frequency with which the person to be protected may be exposed to attack.
Examples of relatively low and high risks and threats could include the following:
Low - A community police officer working a 'quiet' neighbourhood likely to encounter a light threat from youths with pocket knives.
High - A police officer responding to an armed robbery or a terrorist attack certain to encounter armed attackers.
Low - An infantry soldier likely to encounter attacks with mortars and light artillery.
High - A Special Forces soldier on an insurgency or assault operation likely to encounter close-quarter attack with knives and firearms.
Armour can be selected proportionate to the risk and threat.
Body armour standards authorities such as the US National Institute of Justice (NIJ) and the Centre of Applied Science and Technology (CAST) make the job of selecting the right armour easier by setting standards for low, medium and high levels of protection.
Protection levels generally range from low numbers for lower protection levels to high numbers for higher protection as follows:
HOSDB HG1A + KR1 = Low Handgun + Low Antistab.
HOSDB HG2 + KR2 = High Handgun + Medium Antistab.
Ballistic (bullet) resistant body armour is tested by firing specific bullets at specific velocities at samples mounted on plasticine blocks. The armour is then examined for complete perforations and the plasticine examined for depth of indentations. The armour must have no complete perforations and the indentations must be no deeper than a specified depth.
Fragmentation body armour is tested in a similar way to ballistic (bullet) resistant armour, using Fragment Simulating Projectiles (FSP's). There are various Defence Standards for fragmentation armour specifying differing sizes and velocities of fragments.
Stab resistant body armour is tested by dropping weighted knives at specific energies; the samples are then examined for blade penetration through the backface. Penetrations through the backface must not be more than a very small allowable 'safe' limit.