Research Highlights

Technology Performance Summary: MSA Single CWA Detector Kit for Toxic Industrial Chemicals

All Hazards Receipt Facilities (AHRFs) were developed to prescreen for chemical, radiochemical, and explosive hazards in samples collected during suspected terrorist attacks. The technologies used in AHRFs are intended to screen samples prior to a full analysis, helping protect responders, laboratory workers, and others from potential injury.

Evaluations of these technologies are summarized in the technology evaluation report, Testing of Screening Technologies for Detection of Toxic Industrial Chemicals in All Hazards Receipt Facilities. The toxic industrial chemicals (TICs) included in the report were chosen because they might be used during, or develop as a by-product from, a terrorist attack.

The screening technologies are intended:

• To be rapid and qualitative
• To be simple to use and of relatively low cost
• To indicate if samples contain hazardous chemicals
  of concern.

Not all of the technologies evaluated were deemed suitable for the AHRF, although they might be useful for responders on the scene.

Technology Evaluated: MSA Single CWA Detector Kit

Sample Types Evaluated for Indication of: Hydrogen cyanide, cyanogen chloride, and phosgene vapors

Conclusions:
The MSA Single CWA Detector Kit:

• Reliably detected hydrogen cyanide, cyanogen chloride, and phosgene (i.e., 100% accuracy).
• Response time (color change) depended on the concentration of the analyte; however, for these tests, time was around two minutes.
• Some color changes were difficult to distinguish.
• Tested more than one compound at a time with most tubes.
• Prolonged use may cause hand fatigue or cause squeeze counter on pump to fail.
• Uses a relatively simple procedure.

Technology Description and Requirements: This device uses color-indicating tubes with a hand pump to draw sample air through a single indicating tube at a time. Thirty compressions of the hand pump provide the required sample volume and take a couple minutes to complete.

Testing Methodology and Results: Testing was conducted on one TIC at a time. The tested gases were generated by diluting a commercially obtained compressed gas standard. To evaluate the detector, a flow of clean air passed through a clean air plenum, and an equal flow of air containing the tested gas passed through another plenum: the challenge plenum. The instrument was connected to a 4-way valve, through which clean air or the tested gas flowed before being vented into a chemical laboratory hood. The technology was first exposed to the clean air flow. After this, the 4-way valve was switched to the challenge plenum to deliver the TIC gas. The sequence of exposure to clean air, followed by exposure to the TIC gas, was carried out three times in succession. This sequence was followed for each TIC and condition identified in Table 1. For this evaluation, a hydrocarbon mixture interferent was added to the blank, or TIC gas, at a ratio of 1:100 interferent mix to air flow.

Table 1: Summary of MSA Single CWA Detector Kit Test Results

^aA hydrocarbon mixture was used as the interferent.
^bTemperature and relative humidity conditions for vapor tests were: Base = 20 °C and 50% relative humidity, Low = 10 °C and 20% relative humidity, and High = 30 °C and 80% relative humidity.
^cAEGL = Acute Exposure Guide Level and TEEL = Temporary Emergency Exposure Limit.

Contact: Eric Koglin

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