USI has issued a recall on MPC122S smoke and carbon monoxide detectors with the following production dates:

June 2, 2017
June 9,2017
2019 Productions

CR uses two tests to determine if carbon monoxide detectors perform correctly. The first test uses a CO concentration of 100 parts per million (ppm) and determines whether the alarm sounds within 40-165 minutes after exposure to the gas. A concentration of 100 ppm causes a worsening headache starting after 60 minutes. The second test determines whether the alarm sounds within 4-15 minutes at a CO concentration of 400 ppm. Exposure to 400 ppm or greater may prove fatal within 120-180 minutes, or 2-3 hours.

CR determined that some samples of the USI MPC122S sounded the alarm too early, others were too late, and others did not sound at all. Of all the CO alarms that Consumer Reports tested, the MCP122s was the first to ever sound too early. CR tested two samples of the model, and then performed four more tests on each sample. In the additional tests, the detectors only alarmed at 400 ppm, and they went off past the acceptable time frame. The detector sounding the alarm early cause frequent alarms but small concentrations of carbon monoxide often get released daily and have little effect on people.

CR performed even more tests with 2019 models to compare them to the originals from 2017. Those smoke alarms also failed to go off within the appropriate time frame at the 100 ppm test, and instead went off too early. This indicates 2019 models fail to sound off in the correct time frame and need replacing. Additionally, this model may sound too late or not at all, which would not allow time to escape your house and alert the fire department.

For more information on the MPC122S, Photoelectric Smoke & Carbon Monoxide Detector contact USI Electric Inc. at 410-363-3000.

Please note, models with date code productions from 2020 onward are not affected by the recall.