Research Highlights

Technology Performance Summary: Sensidyne Gas Detector Tubes 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: Sensidyne Gas Detector Tubes

Sample Types Evaluated for Indication of: Hydrogen cyanide, phosgene, arsine, chlorine, and hydrogen sulfide in vapor

Conclusions:
The Sensidyne Gas Detector Tubes:

• Reliably detected hydrogen cyanide, phosgene, arsine, chlorine, and hydrogen sulfide (i.e., 100% accuracy).
• Provided results (color change) within seconds; however the number of required pump strokes depends on TIC concentration. For these tests, only one stroke was required for color change. Required one minute per pump stroke.
• Uses a relatively simple procedure with graduated tubes to estimate the TIC concentration.
• Can only test for one TIC at a time.

Technology Description and Requirements: Instrument provides quantitative readings. Single- use glass tubes containing reagents that change color when a suitable volume of air containing the appropriate target chemical is drawn through the tube. A hand pump is used to draw the correct  amount of sample through one tube at a time. One compression of the hand pump provides the 100-mL volume of sample air required by the vendor’s instructions.

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. 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 Sensidyne Gas Detector Tubes 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.

Contact: Eric Koglin

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