Målinger av utslipp fra maskingevær aktuelle for anskaffelse i Forsvaret

The Norwegian Defence is in the process of procuring new light machine guns in calibre 7.62. In relation to this process the Norwegian Defence Logistics Organisation (FLO) has assigned the Norwegian Defence Research Establishment (FFI) to measure emission of fumes and metals from the candidates to quantify the relative health risk of each weapon. A number of components such as carbon monoxide (CO), smoke, particles, ammonia (NH3), lead (Pb), copper (Cu) and Zinc (Zn) is emitted during firing and can be harmful to the user. This study is part of a procurement project, P5040 “Light machine guns for the Norwegian Defence”, where other parameters concerning the weapons performance is assessed. The overall results will provide a basis for the decision of procurement. In this study, fumes from five different weapons were measured; FN MAG titanium, FN MAG original, KSP 58, Minimi (7.62) and Barret. The weapons were tested in two ways; on an indoor shooting range at FLO Test and Verification in Elverum and in a chamber for testing of aerosols (KUA) at FFI. All the weapons were tested with both leaded (M80) and unleaded (NM231) ammunition. In the indoor shooting range two series of 200 shots were fired in showers of 4-6 shots with every combination of weapon and ammunition. A number of analysis instruments were placed around the weapon; Multiwarn II for measuring CO, NH3 and HCN, four PAC7000 for measuring CO and a filter connected to a pump to collect particles. The filters were acid digested and analysed for metals by FFI. Two parallel measurements of shooting in the chamber for testing of aerosols (KUA) were performed for each combination of weapon and ammunition. In addition to filters, Multiwarn and Gasmet, a FMPS was also used to analyse the particle size distribution. The tested weapons seemed to have the same emission of CO regardless of fired ammunition. However, unleaded ammunition had less emission of NH3 and HCN than leaded ammunition. The emission of metals was lowest for FN MAG original. By choosing FN MAG original rather than the other weapons, the shooters exposure for copper, zinc and lead using both unleaded and leaded ammunition can be reduced. From Minimi and FN MAG titanium the emissions of fumes and metals were so similar that they are difficult to rank according to a health perspective. KSP 58 is an old weapon that was included in the test as a reference, the Barret was concluded to be an unfit candidate during other tests, Barret was also the weapon with the largest emission in our tests. The particle size distribution was relatively similar for all types of weapons and ammunition, most of the particles analysed by the FMPS was between 20 and 100 nm. After an overall evaluation of the emission from the tested weapons, the FN MAG original were the most favourable and are therefore recommended on a health risk basis.