Carbon dioxide concentrations inside surgical helmets and powered air-purifying respirators.
Echt-AS; Burroughs-G; Lenhart-S; Booher-D; Rubman-M
American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia. Fairfax, VA: American Industrial Hygiene Association, 1998 May; :81
This poster presents the results of carbon dioxide (CO2) measurements performed inside surgical helmets and powered air-purifying respirators (PAPRs) while test subjects performed an exercise protocol designed to simulate the work of orthopedic surgery. Four types of surgical helmets in a total of 11 configurations were tested from among those manufactured by 3 companies. In addition, two NIOSH-approved PAPRs were evaluated. Test subjects wore typical surgical clothing while performing light exercise (<4 kilocalories/minute) while standing at an upper extremity ergometer set at a workload of 20 watts. Subjects were asked to maintain an exercise rate of 60 revolutions per minute on the ergometer's hand cranks. CO2 measurements were made using a portable infrared indicator. The range of the assembled instrumentation package was extended from 49.50 to 49,500 ppm by diluting the contaminant air stream in a ratio of 9:1 with ambient air scrubbed to remove CO2. CO2 concentration in room air was monitored continuously during all testing using a second, nondiluted CO2 analyzer. Mean CO.2 concentrations from four 15- minute tests of each of 11 surgical helmet configurations and 2 PAPRs tested ranged from 5500 to 11,700 ppm. CO2 concentrations in room air ranged from 375 to 575 ppm, with a mean of 450 ppm. These results indicate that if these surgical helmets and PAPRs are used during operations lasting 8 hours or more, the users will be exposed to CO2 levels exceeding the time-weighted average exposure limit (NIOSH REL, OSHA PEL, and ACGIH TLV) of 5000 ppm. Studies should be conducted to evaluate CO2 exposures during actual orthopedic procedures.
Respirators; Respiratory-equipment; Air-purifying-respirators; Testing-equipment; Equipment-design; Equipment-reliability; Performance-capability; Face-masks; Breathing; Medical-equipment; Headgear; Surgeons; Surgery; Humans; Physical-exercise; Measurement-equipment; Air-contamination; Air-monitoring; Exposure-assessment; Exposure-levels; Exposure-limits; Time-weighted-average-exposure; Permissible-concentration-limits; Carbon-compounds; Dioxides
American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia