Homeland Security chemists invent test for detecting cyanide exposure during fires

In the hunt for a solution to one of burning buildings’ most dangerous effects, chemists from the United States Department of Homeland Security’s Chemical Security Analysis Center (CSAC) have created a test that could help firefighters identify whether civilians have been exposed to toxic cyanide.

The test was created by CSAS chemists Drs. George Emmett and David Reed. It came about as a response to the fact that rapid and non-invasive field tests for carbon monoxide currently do not exist for the smoke-exposed, despite the ease of measuring carbon monoxide exposure with a pulse oximeter. Traditionally, this has left responders to evaluate general signs and symptoms and ultimately guessing as to whether civilians have been exposed.

“Determining whether someone has been exposed to cyanide just from visual observation can be an issue because the symptoms of cyanide and carbon monoxide exposure are very similar,” Dr. Rabih Jabbour, a bioanalytical chemist at CSAC, said. “But they actually need totally different medical treatment.”

In fact, failure to administer a timely antidote to inhalation of such toxins can lead to serious consequences. Even in low quantities, these toxins can be exceedingly damaging, due to denying cells the ability to use oxygen. Thus, the quicker the response, the better, in what are already often chaotic situations.

“Our test takes seconds and is non-invasive,” Emmett said. “It will cost about 10 cents per test — much cheaper than traditional tests, which can cost hundreds of dollars. That’s a huge difference and will be easily affordable to smaller volunteer fire departments and medical responders.”

The test consists of a color test strip with a micropipette. Medical professionals can collect a saliva sample and place it on the test strip to see if thiocyanate is present. The darker red the strip turns, the more thiocyanate present.

“It is important to know how much thiocyanate is produced and how fast it gets into your saliva because it’s going to be a curve, not a spike. We believe that it is relatively rapid, in a matter of minutes; we will confirm that with time series tests,” Reed said. “This is going to be important for any subsequent medical decisions that are made, including administering antidote and further testing.”

Granted, the kit is still itself being tested, but once finished, a prototype test kit will be delivered to the National Urban Security Technology Laboratory in 2022 for a Phase 2 operational assessment with EMTs, before obtaining medical approval to act on results. At that point, DHS will search for a licensing partner to manufacture and sell the kits. Both a patent and trademark for the test kit have already been filed, under the name RAPCYD.