Effectiveness of Paper Towels as a Makeshift Respirator

1
Effectiveness of Paper Towelsas a Makeshift
Respirator

• David LeithDept. of Environmental Sciences and
  EngineeringUniversity of North Carolina at
  Chapel Hill

2
Is This a Crazy Idea?

• Recent events People feel vulnerable
• Attack of 9/11
• Anthrax attacks
• SARS
• What can people do to protect themselves?
• Authorities say Use duct tape, plastic sheets

3
What Can You Do?

• Many potential threats
• Terrorist attacks seem unlikely but get attention
• Fires at home kill 2000-3000/yr from smoke
• Concern about SARS
• Most people dont have a respirator
• Could something else be used

4
Objectives of This Study

• Evaluate makeshift measures for respiratory
  protection
• Readily available at home or office
• Evaluate masks and respirators commercially
  available
• Collection efficiency for respirable particles
• Pressure drop (resistance to breathing )

5
Protective Measures Evaluated

• Makeshift four household items
• Dust Mask three commercially available masks
• N95 NIOSH Certified Respirator three
  commercially available respirators

6
Makeshift Measures

• Handkerchief
• Folded three times eight layers thick
• Bath Towel
• Folded twice four layers thick
• T-shirt
• Folded twice four layers thick
• Paper Towels
• Full roll half roll

Wet andDry
7
Paper Towels

• Need mouthpiece,plug, perforated roll
• Breathe through mouth only
• Face seal unnecessary

Anyone can use
8
Dust Masks

• Package
• use only for sweeping, mowing, pollen relief
• use for comfort and breathing relief from cold
  air, non-toxic dusts, pollen, cut grass
• Cost about 0.40
• Readily available

9
N95 Respirators

• Package
• helps protect against certain particles
• misuse may result in sickness or death
• meets OSHA recommendation for protection against
  SARS
• Cost about 1.75
• Available, if you look

10
Procedure
Five Replicate Tests 1 - Mask, No Mask2 - No
Mask, Mask3 - Mask, No Mask4 - No Mask,
Mask5 - Mask, No Mask
11
Perfect Sealing

• Edges taped
• Best possible seal
• No air flow bypass
• Best possible efficiency

12
Makeshift Respirator Performance
Dry
4
0.4
13
Full Towel Roll Effect of Air Flow
4
0.4
14
Half Towel Roll Effect of Air Flow
4
0.4
15
Bath Towel Wet is Worse
0.4
4
16
T-Shirt Wet is Worse
0.4
4
17
Handkerchief Wet is Worse
0.4
4
18
Dust Masks are Ineffective
4
0.4
19
N95 Respirators are Good
0.4
4
20
Pressure Drop is Low

• Ranged from 0.01 to 1.90 inches of water
• Wet DP gt Dry DP
• No difficulty breathing through any of the devices

21
Other Issues for Paper Towels

• How does the cardboard roll get perforated?
• Manufacturers could do it
• Simple punch could be made
• What about pollutant gases?
• What is adsorptive capacity for paper towels?
• Would toilet paper work as well?

22
Conclusions

• Dust Masks offer Little Protection
• Low efficiency for respirable particles
• Makeshift Measures offer Some Protection
• Bath towel and T-shirt better than handkerchief
• Wetting fabrics decreased performance

23
Conclusions, contd

• N95 Respirators worked Best
• All had efficiencies above 80 for 0.2 lt d lt 4 mm
• Edges taped best possible performance
• Paper Towels worked Relatively Well
• Need mouthpiece, plug, and perforated tube
• No edges to seal
• Efficiency similar to N95 respirators
• Possible to remove pollutant gases?