Minnesota Department of Corrections
PURPOSE: To separate offenders who have suspected or confirmed infectious tuberculosis (TB) from other persons; to provide an environment that allows reduction of the concentration of droplet nuclei through various engineering methods; and to prevent the escape of droplet nuclei from such rooms into the corridor and other areas of the correctional facility using directional airflow.
APPLICABILITY: Minnesota Department of Corrections (DOC); all facilities with negative pressure isolation rooms
DIRECTIVE: The department must keep offenders with suspected or confirmed infectious TB disease in isolation rooms under negative pressure to induce air flow into the room from all surrounding areas (e.g., corridors, ceiling plenums, plumbing chases, etc).
Negative pressure – the minimum pressure difference necessary to achieve and maintain negative pressure that results in airflow into the room is 0.001 inch of water.
A. Monitoring negative pressure isolation rooms when in use
1. The facility safety administrator must begin monitoring immediately prior to or upon the isolation of an offender with suspected or confirmed infectious TB.
2. The facility safety administrator must monitor the negative pressure isolation rooms daily.
3. The supervising lieutenant/designee must conduct daily testing using one of the following procedures. The supervising lieutenant/designee must:
a) Ensure the offender in the room is wearing a surgical mask.
b) Hold non-irritating smoke near the bottom and approximately two inches in front of the door, or at the face of a grill, or other opening if the door has such a feature. Generate a small amount of smoke. The smoke must be held parallel to the door, and the smoke must be issued slowly to ensure the velocity of the smoke does not overpower the air velocity. If an anteroom exists, the direction of the airflow must be tested at the inner door between the isolation room and the anteroom.
c) Move the smoke generator along the bottom of the door.
d) Ensure the room is under negative pressure, by observing the smoke traveling under the door and into the room. If the room is not under negative pressure, the smoke will be blown outward or remain stationary.
4. Staff must check the pressure differential gauge daily (if equipped with) and document it on the room log with the date, time, and initials.
5. If the room is not under negative pressure, the offender must continue to wear a mask until repairs are completed, and a successful smoke test is achieved. If the room cannot be repaired within six hours, the offender must be transported, via ambulance, to the emergency room.
B. Monitoring negative pressure isolation room when not in use - the unit supervising lieutenant/designee must:
1. Conduct monthly non-irritating smoke tests as described in Procedure A; and
2. Document the results on the Negative Pressure Isolation Room Log (attached).
C. The facility safety administer retains all documentation of the negative airflow monitoring process and approved equipment.
D. If the room is not equipped with an anteroom, the facility safety administrator must develop instructions to minimize entry of contaminated air to the corridor. Instructions may include such examples as: minimizing entry into the room, adjusting the hydraulic closer to slow the door movement, and reducing displacement effects.
E. Staff must ensure that air exhausted from the rooms is safely exhausted directly outside, and not recirculated into the general ventilation system. If not exhausted through a high-efficiency particulate air (HEPA) filter, the air is exhausted away from intake vents, operable doors and/or windows, and sidewalks.
F. Communication of hazards - staff must:
1. Post instructions on the door, including:
a) The signal word, “stop;”
b) “Airborne isolation;” and
c) A description of the necessary precautions to take.
2. Label ventilation system components that transport contaminated air with a biological hazard label.
3. Identify and label circuit breakers to prevent unplanned shutdown of the dedicated ventilation system.
G. Cleaning rooms in use - staff must:
1. Use an Environmental Protection Agency (EPA) approved germicide or disinfectant in the routine daily cleaning of isolation rooms;
2. Follow isolation practices while cleaning these rooms;
3. Allow the offender, when appropriate, clean his/her room; and
4. Wipe down cleaning equipment used in the room with an EPA approved germicide or disinfectant before being reissued.
H. Cleaning vacated rooms - staff must:
1. Ventilate the room in accordance with the Air Changes Per Hour Chart (attached) to achieve 99.9% efficacy in removing airborne contaminants;
2. Document the cleaning in the Negative Pressure Isolation Room Log; and
3. After proper ventilation, allow the area offender cleaners to complete the final clean-up using an EPA approved germicide or disinfectant, without using special personal protective equipment other than that required by normal usage of the cleaning chemical.
1. Outside the room
a) Safety administrator approved respirators; and
b) A contaminated linen hamper with lid (soiled linen and waste is handled using standard precautions).
2. Inside the room
a) Garbage holder for contaminated waste;
b) Plastic aprons or gowns; and
c) Disposable gloves.
J. All staff entering an air borne isolation room must wear a National Institute of Occupation Safety and Health (NIOSH) respirator with a minimum filtering efficiency of N-95. The staff wearing respiratory protection must be medically certified and trained. Staff wearing tight-fitting negative pressure respirators must have successfully completed a fit test. Only trained essential staff may enter the room.
A. The facility safety administrator retains documentation of required negative airflow monitoring processes and approved equipment.
REFERENCES: Occupational Safety and Health Administration (OSHA) Directive CPL 2-106
Minnesota Occupational Safety and Health Administration (MNOSHA) Instruction CPL 2-2.48
Morbidity and Mortality Weekly Report “Guidelines for preventing the transmission of mycobacterium tuberculosis in health care facilities,” 1994
Center for Disease Control “Controlling TB in correctional facilities.”
SUPERSESSION: Policy 500.522, "Negative Pressure Isolation Rooms," 8/7/07.
All facility policies, memos, or other communications, whether written or transmitted by electronic means regarding this subject.
ATTACHMENTS: Negative Pressure Isolation Room Test Log (500.522A)
Air Changes Per Hour Chart (500.522B)
Deputy Commissioner, Facility Services