This is an official CDC HEALTH ADVISORY
Distributed via Health Alert Network
Wednesday, October 31, 2001, 21:30 EST (9:30 PM EST)
CDCHAN-00051-2001-10-31-ADV-N
CDC Interim* Recommendations for Protecting Workers from Exposure
to Bacillus anthracis in Work Sites Where Mail Is Handled or Processed
(*Updated from CDC Health Advisory 45 issued 10/24/01)
These interim recommendations are intended to
assist personnel responsible for occupational health and safety in developing a
comprehensive program to reduce potential cutaneous or inhalational exposures
to Bacillus anthracis spores among workers, including maintenance and
custodial workers, in work sites where mail is handled or processed. Such work
sites include post offices, mail distribution/handling centers, bulk mail
centers, air mail facilities, priority mail processing centers, public and
private mailrooms, and other settings in which workers are responsible for the
handling and processing of mail. 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 (<http://www.bt.cdc.gov>). In addition,
each work site should develop an emergency plan describing appropriate actions
to be taken when a known or suspected exposure to B. anthracis occurs.
These recommendations are divided into the
following hierarchical categories describing measures that should be
implemented in mail-handling/processing sites to prevent potential exposures to
B. anthracis spores:
Engineering
controls
Administrative
controls
Housekeeping
controls
Personal
protective equipment for workers
These measures should be selected on the basis
of an initial evaluation of the work site. This evaluation should focus on
determining which processes, operations, jobs, or tasks would be most likely to
result in an exposure should a contaminated envelope or package enter the work
site. Many of these measures (e.g., administrative controls, use of HEPA
filter-equipped vacuums, wet-cleaning, use of protective gloves) can be
implemented immediately; implementation of others will require additional time
and efforts.
1. Engineering Controls in Mail-handling/processing Sites
B. anthracis spores can be
aerosolized during the operation and maintenance of high-speed, mail-sorting
machines, potentially exposing workers and possibly entering heating,
ventilation, or air-conditioning (HVAC) systems. Engineering controls can
provide the best means of preventing worker exposure to potential aerosolized
particles, thereby reducing the risk for inhalational anthrax, the most severe
form of the disease. In settings where such machinery is in use, the following
engineering controls should be considered:
An
industrial vacuum cleaner equipped with a high-efficiency particulate air
(HEPA) filter for cleaning high-speed, mail-sorting machinery
Local
exhaust ventilation at pinch roller areas
HEPA-filtered
exhaust hoods installed in areas where dust is generated (e.g., areas with
high-speed, mail-sorting machinery)
Air curtains
(using laminar air flow) installed in areas where large amounts of mail are
processed
HEPA filters
installed in the building’s HVAC systems (if feasible) to capture aerosolized
spores
Note: Machinery should
not be cleaned using compressed air (i.e., “blowdown/blowoff”).
2. Administrative
Controls in Mail-handling/processing Sites
Strategies should be developed to
limit the number of persons working at or near sites where aerosolized
particles may be generated (e.g., mail-sorting machinery, places where mailbags
are unloaded or emptied). In addition, restrictions should be in place to
limit the number of persons (including support staff and non-employees, e.g.,
contractors, business visitors) entering areas where aerosolized particles may
be generated. This includes contractors, business visitors, and support staff.
3. Housekeeping Controls in
Mail-handling/processing Sites
Dry sweeping
and dusting should be avoided. Instead, areas should be wet-cleaned and
vacuumed with HEPA-equipped vacuum cleaners.
4. Personal
Protective Equipment for Workers in Mail-handling/processing Sites
Personal protective
equipment for workers in mail-handling/processing work sites must be selected
on the basis of the potential for cutaneous or inhalational exposure to B. anthracis
spores. Handling packages or envelopes may result in cutaneous exposure. In
addition, because certain machinery (e.g., electronic mail sorters) can
generate aerosolized particles, persons who operate, maintain, or work near
such machinery may be exposed through inhalation. Persons who hand sort mail
or work at other sites where airborne particles may be generated (e.g., where
mailbags are unloaded or emptied) may also be exposed through inhalation.
Recommendations for
Workers Who Handle Mail
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
Gloves
should be provided in a range of sizes to ensure proper fit.
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.
Different
gloves or layers of gloves may be needed depending on the task, the dexterity
required, and the type of protection needed. Protective gloves can be worn
under heavier gloves (e.g., leather, heavy cotton) for operations where gloves
can easily be torn or if more protection against hand injury is needed.
For workers
involved in situations where a gloved hand presents a hazard (e.g., close to
moving machine parts), the risk for potential injury resulting from glove use
should be measured against the risk for potential exposure to B. anthracis.
Workers
should avoid touching their skin, eyes, or other mucous membranes since
contaminated gloves may transfer B. anthracis spores to other body
sites.
Workers
should consider wearing long-sleeved clothing and long pants to protect exposed
skin.
Gloves and
other personal protective clothing and equipment can be discarded in regular
trash once they are removed or if they are visibly torn, unless a suspicious
piece of mail is recognized and handled. If a suspicious piece of mail is
recognized and handled, the worker’s protective gear should be handled as
potentially contaminated material (See “Guideline For Hand washing And Hospital
Environmental Control,” 1985, available at <http://www.cdc.gov/ncidod/hip/guide/handwash.htm>
Hands should
be thoroughly washed with soap and water when gloves are removed, before
eating, and when replacing torn or worn gloves. Soap and water will wash away
most spores that may have contacted the skin; disinfectant solutions are not
needed.
Additional
Recommendations for Workers Who May Be Exposed through Inhalation
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.
Because facial hair interferes with the fit of protective
respirators, workers with facial hair (beards and or large moustaches) may
require alternative respirators (such as powered air-purifying respirators
[PAPRS] with loose-fitting hoods).
Workers who cannot be fitted properly with a half-mask respirator
based on a fit test may require the use of alternative respirators, such as
full facepiece, negative-pressure respirators, PAPRs equipped with HEPA
filters, or supplied-air respirators. If a worker is medically unable to wear
a respirator, the employer should consider reassigning that worker to a job
that does not require respiratory protection.
In addition, the use of disposable aprons or goggles by persons
working with or near machinery capable of generating aerosolized particles may
provide an extra margin of protection.
In work sites where respirators are worn, a
respiratory-protection program that complies with the provisions of OSHA [29
CFR 1910.134] should be in place. Such a program includes provisions for
obtaining medical clearance for wearing a respirator and conducting a
respirator fit-test to ensure that the respirator fits properly. Without fit
testing, persons unknowingly may have poor face seals, allowing aerosols to
leak around the mask and be inhaled. (See December 11, 1998, MMWR, available
at <http://www.cdc.gov/mmwr/preview/mmwrhtml/00055954.htm>
_________________________________________________
Categories of Health Alert messages:
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Health Advisory- provides important information for a specific incident or
situation; may not require immediate action.
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