May 30, 1995

Mr. Vincent Forte
17 Apache Way
Tewksbury, MA 01876

Dear Mr. Forte:

This letter is in response to questions raised regarding the Occupational Safety and Health Administration's (OSHA) tuberculosis (TB) requirements. The response below is based upon our understanding of the work done in your facility. The facility where you work at is a medical laboratory that performs some TB sputum cultures as requested. The samples will either be cultured or forwarded directly to the state laboratory. All sputum work is done under a hood vented directly to the outside.

Question 1. Are we considered a low risk environment?

Answer: The terms of low, intermediate, or high risk would not be applicable to your facility. The risk terms as used by the Centers for Disease Control and Prevention (CDC) in their guidelines refer to the number of patients actually being treated in a facility or area of a facility.

Question 2. What precautions should be taken when performing this work as required by OSHA?

Answer: OSHA would expect this work to be done in a biological safety cabinet with directional airflow that is exhausted to the outside environment. The exhausted air must be filtered through a high efficiency particulate filter (HEPA). The bio-safety cabinet should have been certified when installed. Follow-up certification should be done every six months and whenever the unit is moved. Since your facility is not a research laboratory for TB, the laboratory does not need to be maintained under negative pressure.

OSHA would expect the facility to have in place decontamination procedures for any spill or equipment used. Work surfaces must be decontaminated at the conclusion of each workshift. Cultures or specimens contaminated with TB must be placed in a container that prevents spills or leakage. The CDC document referenced below also advises that gloves be worn by individuals handling TB specimens.

The CDC also recommends that training of laboratory personnel should also be conducted on the hazards of TB, why PPD tests are necessary and important, signs and symptoms of TB disease, laboratory procedures, and so forth.

For more information we refer you to the following reference:

U.S. Department of Health and Human Services, Public Health Service. Bio-safety in Microbiological and Biomedical Laboratories.
Health and Human Services (HHS) Publication No. (CDC) 93-8395, Stock Number 017-040-00523-7. (May 1993)

Question 3. Is it necessary to have PPD tests performed on employees performing this work?

Answer:Yes. The CDC guidelines for working with TB in a laboratory setting suggest that a baseline with a yearly retest be performed.

Your letter also addressed the same questions with regards to a large phlebotomy staff that makes house calls.

Question 1. Are we considered a low risk environment?

Answer: The terms of low, intermediate, or high risk would not be applicable to phlebotomists making house calls. The risk terms as used by the Centers for Disease Control in their guidelines refer to the number of patients being treated in a facility or area of a facility. If the phlebotomists treat suspect or confirmed TB patients in their homes then they are at risk.

Question 2. What precautions should be taken when performing this work as required by OSHA?

Answer: If patients are treated that have suspect or confirmed TB the phlebotomist should instruct these patients to cover their mouth and nose when coughing and encourage them to wear a mask. The phlebotomist should wear a respirator with HEPA filters. The phlebotomists should receive TB training that should include procedures for identifying potential TB patients, baseline PPD testing, hazards of TB disease, and so forth.

Please refer to the CDC Morbidity and Mortality Weekly Reports, Vol. 43, No. RR-13, October 28, 1994. Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health Care Facilities.

Question 3. Is it necessary to have PPD tests performed on employees performing this work?

Answer: Yes. According to the CDC, a baseline with a yearly retest must be performed.

We hope that this information adequately answers your questions. If you need any further assistance please contact [the Office of Health Enforcement at 202-693-2190].

Sincerely,


Ruth McCully, Director
[Office of Health Enforcement]

[Corrected 10/22/2004]

Compliance Department
U.S. Department of Labor -- OSHA
Frances Perkins Building
200 Constitution Avenue NW
Washington DC 20210

Subj: Mycobacterium tuberculosis guidelines

To whom it may concern:

I have been advised by our local OSHA office to make this inquiry with you.

I work in a medical laboratory. We do not treat patients or perform actual testing for TB. However, sputum specimens for cultures or TB testing do come into our facility. We perform sputum cultures as requested and send any requests for TB culture to the state laboratory. This means that specimens may be either sent directly to the state lab without being opened or opened, specimen removed for the sputum culture and then sent to the state lab for TB testing.

The specimens are only opened by experienced bacteriology technicians. Processing personnel do not open these specimens.

Sputums are handled under a hood vented to the outside. The techs wear special high filtration (0.1 micron) masks. The area is cleaned with the appropriate disinfectants to insure decontamination.

My questions are:

1. Are we considered a low risk environment?

2. What precautions should be taken when performing this work as required by OSHA?

3. Is it necessary to have PPD tests performed on employees performing this work?

Also, we have a large phlebotomy staff which makes housecalls. I am aware that these personnel should not be present if the patient has been requested to collect a sputum specimen. I ask the same three above questions in regard to our phlebotomy department.

Thank you

Vincent Forte