What is the lowest amount of MCHM that can be measured from samples?

According to Dr. Letitia Tierney, Commissioner for the Bureau of Public Health and the State’s Health Officer and Adjutant General James A. Hoyer, the laboratory limit of detection is 10 parts per billion (1/100 parts per million). However, measurements in publicly-released samples were below that limit. For instance, on January 15, there were measurements of 0.45 parts per billion (0.00045 parts per milion) and 0.8 parts per billion (0.0008 parts per million).