A 10-lb. carbon filter within a Sentry Air hood was 99.94% efficient in filtering acetone fumes in this test, meeting NIOSH compliance standards. The test used 100 ml of acetone to create an environment that exceeded the NIOSH threshold limit value. Concentrations were measured at four different points: inside the hood before filtration, after filtration by the outlet of the hood, ambient air, and the operator’s breathing zone.
Testing demonstrated the effectiveness of both a standard activated charcoal filter and an activated charcoal filter specially treated for the removal of aldehydes. The calculated efficiency of removal, within a Sentry Air hood, ranged between 95.45% for the standard activated carbon to >99.33% for the treated activated carbon.
Hydrochloric Acid Vapors
Tested in accordance with NIOSH Test Method 7903, acid gas filter media within a Sentry Air hood appears to have removed >99.99% of hydrochloric acid (HCl) fumes, taking into account potential error in the sample analysis and the analysis method’s detection limits. No HCl was detected in the ambient room atmosphere throughout the test, nor was any detected at the operator’s breathing location, nor at the outlet of the hood.
Isopropyl alcohol (IPA) solvent is often used to clean equipment. In this study, the potential exposure of an operator to IPA fumes was reduced by 98.3% using activated charcoal filter media within a Sentry Air hood. The concentration of IPA in the ambient air near the operator was reduced by 95.6%.
Methyl Ethyl Ketone
A 10-lb. carbon filter within a Sentry Air hood was 99.5% efficient in removing methyl ethyl ketone (MEK) fumes in this test, meeting NIOSH compliance standards. The test used 40 ml of MEK to create an environment that exceeded the NIOSH threshold limit value by 50%.
A 10-lb. carbon filter within a Sentry Air hood reduced the concentration of toluene vapors in the air stream by more than 99% at the hood outlet and in the ambient air and by 98.2% at the operator’s breathing zone. The testing environment was created using 100 ml of a 99% solution of toluene.
A 10-lb. carbon filter within a Sentry Air hood removed xylene vapors from the air stream with 99% efficiency, creating a NIOSH-compliant working environment for the operator. The testing environment was created by placing a total of 125 ml of O-xylene within the hood: 75 ml in a tray and 50 ml in a beaker.