ToxTrak Toxicity Test demonstrates reliable and practical performance in EVT evaluation of rapid toxicity technologies

LOVELAND, Colorado, March 18, 2004 -- The U.S. Environmental Protection Agency (USEPA) recently released data generated during a third-party evaluation of eight commercially available rapid toxicology technologies. The data, posted to www.epa.gov/evt, confirm that the ToxTrak(tm) Toxicity Test from Hach Company yields screening performance that can be effective and practical in early warning water surveillance for chemical contaminants.

Battelle (Columbus, OH) and the Environmental Technology Verification (ETV) Program completed this evaluation under a cooperative agreement with the USEPA. Results show the ToxTrak Test detected qualitative presence of aldicarb, colchicine, cyanide, dichrotophos, thallium sulfate, ricin, and VX agent.

Of the seven common drinking water interferences examined, the ToxTrak Test showed a positive response only to iron, an interference easily addressed by the use of reserved water as a negative control. Unlike other toxicity tests evaluated, it did not register false positive response to aluminum, copper, manganese, zinc, chloramines, or chlorine.

Evaluators also reported the ToxTrak Test - which uses pre-measured reagents and no-maintenance, lyophilized bacteria - was suitable for field use and could easily be administered by operators with little technical training. The test yielded a throughput of approximately 25 samples per hour, much higher than most of the other technologies evaluation.

"These results corroborate what many municipalities already know," affirmed Dan Kroll, Senior Scientist with the Hach Company Homeland Security Technologies Division. "Wastewater treatment plant (WWTP) operators have used this presence/absence test for years - because of its simplicity and reliability - to screen the toxicity of plant influent to the WWTP sludge treatment system. It minimizes required laboratory space and operator time because it can use any type of bacteria culture, including coliform bacteria conveniently freeze dried directly in the test tube, instead of Daphnia organisms that must be nurtured and then starved prior to testing for effective results. Operators read results using a general-purpose photometer suited for many other water quality determinations, and the cost is about $2 per test."

Kroll added that the detection sensitivity reflected by other toxicity technologies could actually be detrimental in screening effectiveness. "One reason for using a rapid toxicity screening test is to identify contamination hoaxes," he explained. "Positive detection of chemicals at or near the USEPA Maximum Concentration Limit (MCL) can result in false alarm response."

Hach specialists in water system monitoring will be present at the company exhibit booth during the American Water Works Association (AWWA) Water Security Congress, April 25-27, in Charlotte, NC, to discuss these evaluation results and answer questions about the ToxTrak Toxicity Test in water network surveillance.

Kroll's laboratory has completed critical evaluation that shows the ToxTrak Test also detects change in bacterial metabolism caused by potential distribution system contaminants not examined in the ETV evaluation. They include the heavy metals arsenic, cadmium, lead, and mercury; a variety of herbicides, insecticides, nematocides and rodenticides; industrial chemicals such as fluoride, sodium diethyl dithiocarbamate (NaDDTC) and PCB (arochlor 1248); low level radioactive salts of uranium and thorium; commercial products such as bug sprays and lawn chemicals, and the chemical warfare agent ß-aflatoxin.

The Hach Company, located in Loveland, Colorado, is a subsidiary of Danaher Corporation (NYSE: DHR). The company is a global leader in water quality analysis systems for laboratory, on-line, and on-site solutions. Visit www.hach.com or call 800-227-4224 in the USA. Outside the USA, call 1-970-669-3050 to order or request additional information.