GAS MASK INFORMATION PAGE:
M9 series:
Obsolete, useful only in filtering dust and large particulate matter.
M17 and early M17A1:
Obsolete and potentially unsafe due to parts failure and deterioration. Potentially useful filtering dusts.
Post-1978 M17A1 and M17A2:
Potential use only with fresh filters against riot agents and dusts. Not safe for NBC protection. The last verified use of M17A2 masks in the US military that I have seen is 15 June 1998 when D Co., 3/126 Infantry (Big Rapids, MI) performed preventive maintenance on them.
M40:
(late 1980s-early 1990s) has silicone facepiece prone to HD penetration. This does not disqualify the mask from use but a "second skin" hood should always be in place. The white plastic faceform issued with some Gulf-era M40s is useless and can actually damage the mask from stress over time; it should be discarded. The hood may tear away from the elastic holding it to the facepiece portion over time. See my M40/M40A1 comparison photos for an example of this.
M40A1:
An excellent mask with no major concerns at this time. Improved inner nosecup over the M40, also quick-doff hood and second skin for easier decon. Issued with several different second skins, notably the Army version which is held to the facepiece with small tabs, the USMC variant which includes hook-and-pile fasteners around the "nose" area of the mask, and finally the streamlined universal second skin with a slightly larger lip around the edge.
LATEST M40A1:
As of June 2003, I was told that the M40A2 had been issued. This is incorrect; the M40A1 just has had a newly-issued revision. It is identical to the older A1 except it includes a universal second skin and is issued with a cotton-nylon softsided bag. All newly-issued M40A1 masks will come with the "universal second skin." The purpose is to allow the wearing of the mask without the rubberized hood while wearing hooded protective suits like the Saratoga and JSLIST. Mask hoods have a tentative eight year shelf life.
2003 READER CONTRIBUTIONS: Thanks to a contributors from Chemical units in the US Army, please read the following that they have had to add.
1. When storing long term (more than 30 days), ensure that the quick doff hood is really pressed into the upper portion of the outserts. This can help avoid a permanent set. The new universal second skin is wreaking havoc on the M40A1 at the upper portion due to it's redesigned weakened state.
2. Personnel should carefully stow the mask in the new smaller version carrier. This can also help to ensure a longer life with this facepiece. Make sure the mask has it's intended open shape before closing the carrier to reduce permanaent set.
3. If you remove mask after a long term and it seems to have permanent set, just lay it out in a warm area for a couple of hours and recheck it. The silicone seems to bounce back over the old natural rubber of the M17 series mask.
4. The hood with velcro nose tabs is also issued to soldiers in the 10th
Mountain. They suffer from terrible warping in the chin-pocket due to poor
stitching under the outlet-valve cover. This can be modified without hindering
performance (see my M40/M40A1 comparison photo for an example of this).
M45 series::
Newest issued mask, part of the Land Warrior System. May never make it beyond special units due to the upcoming M50 series, but not for the lack of quality. Limited field of vision compared to M40 or MCU2P, however lenses being positioned where they are give superior peripheral vision. Otherwise quite similar in design and purpose to the M40 series. Prototypes and early issue had six-point head harnesses, newer issue seem to all have the "net" style head webbing, for lack of a better term. Click here for photo of the mask and its issue waterproof/surfproof carry bag.
M50 series::
Currently still designated XM50 (experimental); Click here for the page I have created about this new mask.
MCU-2/P series:
Another excellent mask with panoramic lens. Should be kept outside of bag unless threat is imminent; over time and changing weather/humidity the lens may develop cracks or warp if kept compressed in bag. Mask hoods have a tentative eight year shelf life. Though my military unit is issued the M40A1 mask, I prefer the MCU2P for its superior field of view and seemingly lower breathing resistance.
