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Anthrax Exposure and Personal Protective Equipment
Last Updated 11-29-02
On October 31, 2001 the Centers for Disease Control and Prevention (CDC) updated its October 24th official health advisory for mail handlers. This revision, entitled “CDC Interim Recommendations for Protecting Workers from Exposure to
Bacillus anthracis in Work Sites Where Mail Is Handled or Processed,”
http://www.bt.cdc.gov/DocumentsApp/Anthrax/10312001/han51.asp , along with the CDC’s “Interim Recommendations for Firefighters and Other First Responders for the Selection and Use of Protective Clothing and Respirators Against Biological Agents,” released on October 25, 2001, represents the most recent information available on appropriate PPE for Anthrax. This article summarizes these two recent CDC advisories and contains other PPE related information and links on Anthrax that Lab Safety Supply’s Technical Services Department has discovered.
Recent PPE Advisories and Recommendations
CDC's Interim Recommendations for Mail Handlers
The October 31, CDC advisory states, “These interim recommendations are based on the limited information available on ways to avoid infection and the effectiveness of various prevention strategies and will be updated as new information becomes available. These recommendations do not address instances where a known or suspected exposure has occurred. Workers should be trained in how to recognize and handle a suspicious piece of mail (www.bt.cdc.gov ). In addition, each work site should develop an emergency plan describing appropriate actions to be taken when known or suspected exposure to
B. anthracis occurs.”
The recommendation lists a hierarchy of measures to be used to prevent potential exposures to
B. anthracis spores. In hierarchical order the measures are:
-
Engineering controls
- Administrative controls
- Housekeeping controls
- Personal protective equipment (PPE) for workers
Under PPE the recommendation states, “Personal protective equipment for
workers in mail-handling/processing work sites must be selected on the basis of
potential for cutaneous or inhalational exposure to B. anthracis spores.”
It advises the use of gloves and long sleeves for workers who handle mail. The
recommendation provides nine bullet points to assist in the selection of proper
gloves.
In terms of respiratory protection the CDC states, “Persons working with or
near machinery capable of generating aerosolized particles (e.g. electronic mail
sorters) or at other work sites where such particles may be generated should be
fitted with NIOSH-approved respirators that are at least as protective as an N95
respirator. Persons working in areas where oil mist from machinery is present
should be fitted with respirators equipped with P-type filters.” The
recommendation states that employees with facial hair that interferes with the
fit of the respirator face piece, and employees that can not pass a fit test
with a tight fitting air purifying respirator (APR) may require the use of a
powered air purifying respirator (PAPR) with high efficiency particulate
absolute (HEPA) filters. Aprons and goggles are also suggested for those working
near machinery capable of generating aerosolized particles.
The previous recommendation from the CDC for mail handlers (the Oct 24th
release http://www.bt.cdc.gov/DocumentsApp/45.pdf),
advised those working near automated mail sorting equipment should use an N, R,
or P100 respirator and those sorting mail by hand should use an N95 respirator
as the minimum levels of respiratory protection.
CDC's PPE Recommendations for Investigators and Responders
In the CDC's October 25th interim recommendations for firefighters and other
first responders, the levels of protection are tiered and "based upon the
anticipated level of exposure risk associated with different response
situations." Recommendations range from self-contained breathing
apparatuses (SCBAs) and Level A protective suits, for incidents where the
contaminant is unknown or the event is "uncontrolled," down to full
face respirators with P100 filters or powered air purifying respirators (PAPRs)
with high efficiency particulate absolute (HEPA) filters, for more controlled
incidents. Please refer to the CDC's October 25th recommendations for details http://www.bt.cdc.gov/DocumentsApp/Anthrax/Protective/10242001Protect.asp.
Additional Information on Anthrax PPE
The above information represents the most recent governmental recommendations
and advisories on PPE to prevent exposure to Bacillus anthracis. Lab Safety
Supply's Technical Services Department has uncovered additional resources and
links on PPE for Anthrax and biological agents in general. The following
summarizes these findings.
Definition of Anthrax
According to the May 12th, 1999 issue of the Journal of the American Medical
Association (JAMA), http://jama.ama-assn.org/issues/v281n18/ffull/jst80027.html,
"Bacillus anthracis derives from the Greek word for coal, anthrakis,
because the disease causes black, coal-like skin lesions. Bacillus anthracis
is an aerobic, gram positive, spore-forming, non-motile Bacillus species. The
non-flagellated vegetative cell is large (1-8 micron in length, 1-1.5 microns in
breadth). Spore size is approximately 1 micron." Having knowledge that
anthrax is a particulate with a spore size of 1-micron helps when attempting to
identify appropriate PPE.
Respiratory Protection
Since Bacillus anthracis a biological particulate, an air-purifying
respirator (APR) equipped with a mechanical filtering element would be the
minimum level of respiratory protection required. A joint study by the
Department of Defense (DOD), the National Institute for Occupational Safety and
Health (NIOSH), and the Occupational Safety and Health Administration (OSHA),
came out with a report titled "Chemical and Biological Respiratory
Protection Workshop Report," http://www.cdc.gov/niosh/2000-122.html.
This report states, "Currently, NIOSH approved particulate filters, (N, R,
and P 100 filters) have the capability to filter out biological agents. Although
respirators can filter out biological agents, face-seal leakage - which is
affected by facial structure and face piece models and sizes - is a significant
problem. Factors such as beard growth, scars, and perspiration also affect fit
and leakage."
While N100, R100, or P100 mechanical filtering elements are affective against
biological agents such as Anthrax, they're only affective if the face piece fits
properly. OSHA has established specific guidelines for respirator fit testing.
For more information on this topic see our EZ Facts number 140, Respirator Fit
Testing Requirements and Procedures http://www.LSS.com/refinfo/ezfacts/ezf140.htm.
In addition to the inhalation hazard Anthrax presents, exposure to the skin
is also of concern. The cutaneous form of Anthrax can develop through contact
with the skin. According to the JAMA report, Anthrax can also be absorbed into
the body through previous cuts or abrasions. The report states, "Areas of
exposed skin, such as the arms, face, hands, and neck are most frequently
affected." In general, there is the potential that biological agents may be
absorbed into the body through mucous membranes (i.e. eyes, nose). Due to these
concerns, respiratory protection that incorporates protection for the face such
as a full face respirator with N100, R100, or P100 filters, or full face powered
air purifying respirator (PAPR) with High Efficiency Particulate Absolute (HEPA)
filters should be used. The highest level of respiratory
protection is provided by either a self-contained breathing apparatus (SCBA) or
a pressure demand airline respirator that incorporates an egress (escape) bottle
of breathing air. Again, it's vital that the face piece be properly fitted to
achieve the maximum level of protection from any tight fitting respirator.
For more information on respirator basics, review the following EZ Facts
documents,
http://www.LSS.com/refinfo/ezfacts/ezf275.htm,
http://www.LSS.com/refinfo/ezfacts/ezf195.htm,
http://www.LSS.com/refinfo/ezfacts/ezf196.htm,
http://www.LSS.com/refinfo/ezfacts/ezf141.htm.
Clothing
When it comes to clothing, standard Tyvek® will hold out 99.9% of all dry
particles down to 0.5 microns. According to an information sheet from DuPont,
the manufacturer of Tyvek®, "Garments made of Tyvek® can be used against
dry chemical, biological and radioactive particle hazards and against liquid
hazards when the amount of liquid is small and the pressure is low. For liquid
chemical, biological or radioactive hazards, the appropriate style garment made
of Tychem® can be used. For gas and vapor hazards, vapor protective suits made
of Tychem® fabrics are appropriate when worn with the proper respiratory
equipment."
The Tychem® garments incorporate layers of laminates to provide the liquid
protection. Both Tyvek® and Tychem® garments are considered disposable and
should be disposed of after an exposure or potential exposure to anthrax causing
spores or other biological and chemical agents.
In terms of hand protection, the goal is to establish a barrier between the
Bacillus anthracis and any potential cut or abrasion on the hands. According to
the CDC's October 31st Advisory (see link in opening paragraph),
"Protective, impermeable gloves should be worn by all workers who handle
mail. In some cases, workers may need to wear cotton gloves under their
protective gloves for comfort and to prevent dermatitis. Skin rashes and other
dermatological conditions are a potential hazard of wearing gloves. Latex gloves
should be avoided because of the risk of developing skin sensitivity or
allergy." The CDC states, "The choice of glove material (e.g., nitrile,
vinyl) should be based on safety, fit, durability, and comfort. Sterile gloves
(e.g., surgical gloves) are not necessary." For more information on gloves
and latex sensitivity, see the following EZ Facts documents, http://www.LSS.com/refinfo/ezfacts/ezf191.htm,
http://www.LSS.com/refinfo/ezfacts/ezf126.htm.
Decontamination
To decontaminate materials exposed to Bacillus anthracis, a document
from the U.S. Navy Manual on Operational Medicine and Fleet Support entitled
"Biological Warfare Defense Information Sheet" states,
"Disinfection of contaminated articles may be accomplished using
a 0.05% hypochlorite solution (1 tbsp. bleach per gallon of water). Spore
destruction requires steam sterilization."
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