Personal Hygiene

Basics Masks Handwashing Attendance Sneezing Handling Air Travel New Approaches Respiratory Condoms

Basic Flu Personal Hygiene From The CDC

  • Cover your nose and mouth with a tissue when you cough or sneeze—throw the tissue away after you use it.
  • Wash your hands often with soap and water, especially after you cough or sneeze. If you are not near water, use an alcohol-based hand cleaner. Alcohol-based hand cleansers must be at least 60% alcohol to be effective; not all are so you should check the label.
  • Stay away as much as you can from people who are sick.
  • If you get the flu, stay home from work or school. If you are sick, do not go near other people so that you don’t make them sick too.
  • Try not to touch your eyes, nose, or mouth. Germs often spread this way.

edit top


  • A NIOSH approval is issued to a respirator only after it has been evaluated in the laboratory and found to comply with all the requirements of Title 42, Code of Federal Regulations, Part 84, including a review of the manufacturer’s quality plan. The Nano Guard N95 Particulate Respirator is not certified and approved by NIOSH. See also Health Care Worker Safety During a Pandemic and Personal Protective Equipment (PPE)
  • What is N-95?
Filters and infectious particles
Particles greater than 5 microns fall out of the air
Particles 1 – 5 microns in diameter can enter upper airways
0.1 – 1 micron particles enter lower lungs and alveolar ducts

Examples of particle size:

  • Viruses 0.02 to 0.3 microns - N95 mask not effective
  • Bacteria 0.5 to 10 microns - N95 mask effective
  • Mold spores 1 to 70 microns - N95 mask effective
  • Fungi 2 to >200 microns - N95 mask effective

Particulate filter efficiency is based on ability to remove particles greater > than 0.3 microns in diameter (medial aerodynamic diameter of 0.3 um)

It is also very important to note, that although the CDC recommends these products as suitable levels of protection against the H5N1 virus, the testing criteria used to certify these products does not include any biological agents.

NIOSH only tests the filtration efficiencies of N95 facemasks against salt particles, and does not currently employ any standards to test against live agents.

Hard data on masks is hard to come by. WHO recently published two companion papers on non-pharmaceutical interventions by the World Health Organization (WHO) Writing Group.

  • From the first:
Data do not exist to quantify the relative efficacy of surgical masks versus respirators in preventing influenza infections in exposed persons, but surgical masks should protect against large droplets, believed to be the major mode of transmission (8).
  • From the second:
Wearing Masks in Public
Apparently no controlled studies assess the efficacy of mask use in preventing transmission of influenza viruses. During the 1918 influenza pandemic, mask use was common and even required by law in many jurisdictions. Skepticism arose, however; the medical officer of health for Alberta, Canada, noted that cases of disease continued to increase after mask use was mandated, and public confidence in the measure’s efficacy gave way to ridicule (6).
In Australia, mask-wearing by healthcare workers was thought to be protective, and given evidence of transmission in a closed railway carriage, it was concluded that mask wearing “in closed tramcars, railway carriages, lifts, shops, and other in enclosed places frequented by the public had much to recommend it.” However, mask-wearing in the open air, as initially required in Sydney, was later thought to be unnecessary (24).
In the United States, persons also wore masks as a protective measure. A report from Tucson, Arizona, noted that early measures included “…isolation of ill people, closure of schools, churches, theatres, etc. The epidemic worsened however. As weeks passed, criticism of the measures was expressed, most vocally by businesses losing money but also by religious and educational institutions. To allow some businesses to reopen, city officials ordered ‘masks to be worn in any place where people meet for the transaction of necessary business’ … (and later by) all persons appearing in public places. Within a few days, there was virtually universal compliance with mask wearing, but the epidemic was subsiding” (29).
During the SARS epidemic in 2003, 76% of Hong Kong residents reported wearing masks in public. As noted above, influenza virus isolation rates decreased, but since multiple measures were implemented, the contribution of mask use, if any, is uncertain (20). In case-control studies conducted in Beijing and Hong Kong, wearing masks in public was independently associated with protection from SARS in a multivariate analysis. One study found a dose-response effect (30). Methodologic limitations of the studies (e.g., retrospective questionnaire design) limit drawing conclusions (30,31).

See also:

The Institute of Medicine Committee on Personal Protective Equipment for Healthcare Workers During an Influenza Pandemic held a scientific workshop on February 22, 2007. PowerPoint Slide shows are available at the link.

An example of Hong Kong mask policy can be found here at the Chinese University of Hong Kong (CUHK) web site.

  • Questions raised about study on masks as aerosol barrier Feb 2007, CIDRAP, and see also:
  • CBN Report: Surgical Masks May Provide Significant Aerosol Protection Feb 2007
  • OSHA, Feb 2007
  • Interim recommendations from and HHS
  • Aerosols and flu transmissibility -review in EID
  • Policy Review: Nonpharmaceutical Interventions for Pandemic Influenza, International Measures (article 1)
  • Policy Review: Nonpharmaceutical Interventions for Pandemic Influenza, International Measures (article 2)
  • Institute of Medicine Reusability of Facemasks During an Influenza Pandemic: Facing the Flu
  • Singapore Medical Association article about masks and other Personal Protective Equipment (PPE)
    about SARS experience, N95 vs surgical vs cloth (pdf)
  • 3M on SARS and Masks from an Australian perspective (.pdf)
  • 2004-05 Interim Guidance for the Use of Masks to Control Influenza Transmission
    from the CDC
  • NIOSH-Approved N95 Disposable Particulate Respirators
  • NIOSH-Approved P95 Disposable Particulate Respirators
  • The National Personal Protective Technology Laboratory (NPPTL)
    website of the Centers for Disease Control and Prevention (CDC) - Respirators (masks); standards and information
  • N95 disposable respirators from the Minnesota Department of Health

edit top

Low-tech masks

This is an area where some research or innovation is needed. Imagine you’re a mother with a diseased infant in an extremely poor setting. The low-tech approach works for water filters, so wouldn’t it be good if we could have the same for air-filters or masks? Consider bandanas, cloth masks, etc. This is being tried at simple masks which refers to a scientific paper reporting the developement and testing of a low-tech, washable mask which provides a less-than-perfect protection (as all masks do) and might have a role in diminishing transmission.

See also Simple Respiratory Mask from a cotton undershirt.

Microfiber Masks

  • Explore new microfiber materials. A 500- or 600-thread-count bedsheet purchased from a local store may offer far superior protection from infectious droplets than low-tech masks made from, say, teeshirt material. Microfiber fabrics are becoming commonplace in every area of textile development, from the above-mentioned bedsheets to handbags to clothing to entire couches.

edit top


  • Essay on hygiene
  • More on handwashing
  • Guidelines for good handwashing (pdf)
  • Guide to Handwashing – the video (mpeg, 3.5 MB)

edit top

Attendance at work/school

edit top


  • Sneezing or coughing into your elbow or arm is less likely to spread viral droplets than coughing into your hands (still better than no coverage of nose and mouth)… this way, less droplets will be spread to doorknobs, etc.

edit top

Reduce doorknob handling

  • Replace round doorknobs with “lever” ones, which don’t need to be grasped.

edit top

Air travel

  • Need study evidence on the efficacy of a light coat of vaseline or other petroleum jelly on the inside of the nose before air travel to seal microcracks in skin and reduce droplet transfer. Anecdotally it’s useful … use your little finger.

edit top

New Approaches to Hygiene

  • A new paradigm in respiratory hygiene: increasing the cohesivity of airway secretions to improve cough interaction and reduce aerosol dispersion
    Zayas, et al, BMC Pulmonary Medicine 2005

edit top

“Respiratory condoms”

Please take this mostly as a first provocative idea, but maybe a derived idea might have some value. We may need a CopingCreatively section: based on sound scientific knowledge and checking feasibility and real benefits, but also trying to use our brains to find better ways forward.) Bank clerks are behind glass protection - why can’t healthcare providers and cash-counter workers have some kind of plastic wall between clients and themselves? It would just be a couple of long wooden sticks nailed to each wall, and a plastic sheet nailed to the wood. If you want to explore the patients’ belly you can have gloves like those in incubator boxes. I think it would work if the “wall” is tall enough. The concept here is not perfect protection, but reduce unneeded respiratory contacts (say from 10 million contacts a day to 1 million contacts a day) while keeping societies functioning.

Shaking Hands

I do not know of any studies supporting this, but common sense dicates that shaking hands with other people when greeting them should not be done, as virus may be passed that way very directly.

Discuss this entry in the Forum.

Page last modified on December 07, 2008, at 07:47 PM by pogge