M256A1 Chemical Agent Detector Kit

The M256A1 kit is used to confirm the absence, or detect the presence, of chemical agents in air. Use of the kit can also determine the type of agent present: nerve, blister, blood Lewisite or Mustard.

Critical chemical detection

The M256A1 Kit can detect and identify field concentrations of nerve, blister (including Mustard and
Lewisite), and blood agents in both vapor and liquid form in about 15-20 minutes. Used after a chemical attack, the M256A1 Kit can determine the type of agent present, or can confirm the absence of a hazardous concentration of an agent — making it easier to determine if it’s safe to unmask or reduce the protective posture level.

In 2012, the State of California’s FIRESCOPE Standardized Equipment List, listed the M256A1 as a required item for emergency and Hazmat first responders.

NSN#: 6665-01-133-4964

How the chemical detectors work

The sampler-detectors consist of a series of ampoules containing reagents. The ampoules are attached to a small hand-held card. When the ampoules are crushed between the fingers, the liquid reagents can flow down plastic tubes to three distinctively shaped test spots.

Each test spot is open to the air and, when the reagent wets the test spot, it interacts with the chemical agent in the air, and will turn the test spot a certain color.

If there is no agent present, then there will be no reaction. The reaction indicates whether a chemical agent is, or is not, present in the air.

For example, a color change in the square area indicates the presence of blister agents, the circular test spot is for blood agents, and the star-shaped field signals nerve agents.

The sampler-detectors identify the following agents:

• Nerve Agents (V- and G- types)
• Blister Agents (CX, HD, L)
• Blood Agents (AC, CK)
• Lewisite (L)
• Mustard (H, HD, HN, and HT)

The kit does not need to be pointed in a certain direction for it to detect chemical agents, nor does it require a close proximity to work effectively.

What’s in the M256A1 detector kit?

• 12 Sampler-Detectors
• One booklet of M8 Paper
• Instruction cards attached by a lanyard to the plastic carrying case.

Each kit contains 12 disposable sampler detectors, one book of M8 Paper, and one set of instruction cards. The case is made from molded, high-impact plastic with a nylon carrying strap and nylon belt attachment.

Each sampler-detector contains a square spot for blister agents, a star test spot for nerve agents, and a lewisite detecting tablet and rubbing tab. The test spots are made of standard laboratory filter paper. When the ampoules are crushed between the fingers, channels in the plastic sheets direct the flow of liquid reagent to wet the test spots.

Each test spot or detecting tablet develops a distinctive color which indicates whether a chemical agent is, or is not, present in the air. The kit does not need to be pointed in a certain direction for it to detect chemical agents, nor does it require a close proximity to work effectively.