Vacuum Cleaners & Bags
The effect of vacuum cleaners on the concentration and particle size distribution of airborne cat allergen.
AUTHORS: Woodfolk JA; Luczynska CM; de Blay F; Chapman MD; Platts-Mills TA
AUTHOR AFFILIATION: Department of Medicine, University of Virginia Health Sciences Center, Charlottesville 22908.
SOURCE: J Allergy Clin Immunol 1993 Apr; 91(4): 829-37
CITATION IDS: PMID: 8473670 UI: 93232472
BACKGROUND: Vacuum cleaners are essential for the removal of dust
from the surface of carpets; however, they may also contribute to airborne
dust both by leakage through the cleaner and disturbance of floor dust.
METHODS: The present studies used established techniques for measuring airborne Fel d 1 to study the effects of vacuum cleaners on airborne cat allergen under laboratory conditions and in houses with cats. Nine different models were loaded with dust containing 50 mg Fel d 1 and run for 15 minutes in a laboratory room (volume approximately 18m3). Leakage was expressed as the airborne concentration of allergen in nanograms per cubic meter.
RESULTS: Cleaners incorporating a double-thickness dust bag either did not leak, that is, less than 0.4 ng Fel d 1/m3 or had minor leakage approximately 5 ng/m3 Vacuum cleaners with single-thickness paper bags leaked more, that is, 15 to >90 ng/m3 with the exception of the cleaner with an efficient outer bag. Detailed studies on a vacuum cleaner that leaked showed that placing dust in the bag, replacing the dust bag with a double-thickness bag, and placing an electrostatic filter over the exhaust reduced levels from greater than 90 ng/m3 to less than 2 ng/m3. Two water-filter vacuum cleaners each emitted cat allergen (up to >100 ng/m3) with a mean of approximately 90% on particles less than 2.5 microns diameter. This emission could be almost completely controlled by taping electrostatic filter paper over the air outlet.
CONCLUSIONS: In houses with cats, different models of vacuum cleaners could either reduce or increase total airborne allergen, and could also selectively increase certain particle sizes. These results suggest that cat allergen is a good model for studying the effectiveness of vacuum cleaners recommended to allergic patients.
Assessment of vacuum cleaners and vacuum cleaner bags recommended for allergic subjects.
AUTHORS: Vaughan JW; Woodfolk JA; Platts-Mills TA
AUTHOR AFFILIATION: University of Virginia Asthma and Allergic Diseases Center, Charlottesville, VA 22908, USA.
SOURCE: J Allergy Clin Immunol 1999 Nov; 104(5): 1079-83
CITATION IDS: PMID: 10550756 UI: 20020198
BACKGROUND: High-quality vacuum cleaners and vacuum cleaner bags
are often recommended to allergic patients as a means of reducing indoor
allergen exposure. A number of vacuum cleaners on the market today claim to
capture 99.9% of particles 0.3 micron or larger entering the vacuum cleaner,
and many vacuum cleaner bags are now being sold as microfiltration bags.
OBJECTIVE: The purpose of this study was to compare the allergen-trapping abilities of vacuum cleaners and to use a new technique for testing vacuum cleaner bags that are recommended for allergic patients.
METHODS: Vacuum cleaners were tested in an 18m3 laboratory room permeated with dust containing high levels of cat allergen by using techniques previously described. Air was sampled using parallel filters in conjunction with a particle counter. The filters were assayed by ELISA for cat allergen (Fel d 1). Vacuum cleaner bags were tested by using a modified dust trap to pull sieved house dust containing a known amount of Fel d 1 across the material used for the bag. Allergen passing through the bag was trapped on a filter covering the exit of the trap and analyzed for Fel d 1.
RESULTS: In general, vacuum cleaners designed for allergic patients leaked lower amounts of allergen (<0.5-4.04 ng/m3) than that found in our previous studies (<0.5-100 ng/m3). Single-layer vacuum cleaner bags performed poorly (1250-2640 ng recovered) compared with most of the 2- and 3-layer microfiltration bags (0.53-2450 ng recovered). The range of allergen recovered from the 2-layer bags (0.93-2450 ng recovered) highlighted the variability found between manufacturers.
CONCLUSIONS: The results suggest that although allergen leakage has been reduced, there is still room for improvement. A method of testing allergen leakage by using Fel d 1 should be applied to vacuum cleaners and bags recommended for allergic patients.