Document x6KmrOY5wdY101774gYxbJQQ

3M Occupational Health and Environmental Safety Division 3M Center St. Paul, Minnesota 55144-1000 612/733 1110 Mark Puskar Abbott Laboratories, D-38A 1401 Sheridan Rd North Chicago, IL 60064 Dear Mark: I want to apologize for the delay in responding to your methylene chloride study. We would like to participate in the study, however it should be noted that our 3M 3520 Organic Vapor Monitor has limitations. The monitor has a maximum capacity micrograms at high relative humidities (i.e., >60%). This capacity will increase as relative humidity drops. Based on a capacity of 3000 micrograms, the maximum concentration measurements are as follows: 15 minutes: 240 minutes: 480 minutes: 1518 ppm 120 ppm (' 6cT) ppm Based on this information we recommend that sampling be limited to four hours when methylene chloride concentrations are unknown. However, if concentrations are expected to be at the TLV (50 ppm) or below, the use of the 3520 monitor is acceptable. The validation study that Abbott outlined calls for a sampling site that is greater then 50 ppm methylene chloride. If an 8 hour sample was collected at this location, it is feasible that the capacity of the monitor may be exceeded. This sampling site pushes the limitation of the monitor. However, all of the other sampling sites, including the sampling times, fall within the limitations of the 3M 3520 monitor. We would like to participate in the study, however, we want to caution you that our 3M 3520 monitor cannot be used in all situations, just like most other sampling devices. QOO WorWwldo Sponsor '992 Olympic Games 3M 110842 Mark Puskar Page Two October 16, 1992 Per our discussion, we have spiked organic vapor monitors with methylene chloride. We have four sets with triplicates in each set. The methylene chloride concentrations are as follows: Set A: Set B: Set C: Set D: Set F: 1330 microgram 265 microgram 530 microgram 2650 micrograms Blanks If you have any questions, please feel free to give me a call at 612-737-4459. I look forward to working with you and Abbott in the future. Regards, Robert A. Weber, CIH Technical Service Representative 3M Occupational Health & Environmental Safety Division RAW:llj/54 Enclosure 3H 110843