US Environmental Protection Agency

Office of Pesticide Programs

Microbiology Laboratory

Environmental Science Center, Ft. Meade, MD

Monitoring of Laboratories for Airborne Contaminants
Standard Operating Procedures (SOPs)

Office of Pesticide Programs

SOP Number: QC-02-04

Date Revised: 09-09-10


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SOP No. QC-02-04
Date Revised 09-09-10
Page 1 of 7

EPA/OPP MICROBIOLOGY LABORATORY
ESC, Ft. Meade, MD

Standard Operating Procedure
for

Monitoring of Laboratories for Airborne Contaminants
SOP Number: QC-02-04
Date Revised: 09-09-10

Initiated By:		Date: / /

Print Name:	

Technical Review: 	Date: / /

Print Name:

Technical Staff

QA Review:		Date: / /

Print Name:	

QA Officer

Approved By:		Date: / /

Print Name:	

Branch Chief

Effective Date:	/ /

Controlled Copy No.:

Withdrawn By:

Date: / /


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SOP No. QC-02-04
Date Revised 09-09-10
Page 2 of 7

TABLE OF CONTENTS

Contents
Page Number

I.0	SCOPE AND APPLICATION	3

2.0 DEFINITIONS	3

3.0 HEALTH AND SAFETY	3

4.0 CAUTIONS	3

5.0 INTERFERENCES	3

6.0 PERSONNEL QUALIFICATIONS	3

7.0 SPECIAL APPARATUS AND MATERIALS	3

8.0 INSTRUMENT OR METHOD CALIBRATION	3

9.0 SAMPLE HANDLING AND STORAGE	3

10.0 PROCEDURE AND ANALYSIS	4

II.0	DATA ANALYSIS/CALCULATIONS	4

12.0 DATA MANAGEMENT/RECORDS MANAGEMENT	5

13.0 QUALITY CONTROL	5

14.0 NONCONFORMANCE AND CORRECTIVE ACTION	5

15.0 REFERENCES	5

16.0 FORM AND DATA SHEET	 6


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SOP No. QC-02-04
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1.0 SCOPE AND APPLICATION:

1.1 This SOP describes a method for determining the occurence (number and type) of
airborne microorganisms in the laboratory. This procedure is based on aspects of
references 15.1 and 15.2. Additional attributes have been added to detect airborne
contamination in specific environments.

2.0 DEFINITIONS:

2.1	CFU = Colony Forming Unit

2.2	BSC = Biological Safety Cabinet

2.3	TSA = Tryptic Soy Agar

2.4	TSB = Tryptic Soy Broth

2.5	NB = Nutrient Broth

2.6	SDA = Sabouraud Dextrose Agar

3.0 HEALTH AND SAFETY: Not applicable

4.0 CAUTIONS: None

5.0 INTERFERENCES:

5.1	Building construction, power outages and equipment maintenance may cause
transient aberrant counts (see 14.0). These events should be considered in
interpreting results of the air testing and efficacy tests conducted during that time.
Note these events in the comments section of the Air Monitoring Record Form
(see 16.1).

5.2	Media must pass sterility assessment in advance of use.

6.0 PERSONNEL QUALIFICATIONS:

6.1 Personnel are required to be knowledgeable of the procedures in this SOP.

Documentation of training and familiarization with this SOP can be found in the
training file for each employee.

7.0 SPECIAL APPARATUS AND MATERIALS: None

8.0 INSTRUMENT OR METHOD CALIBRATION: Not applicable


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SOP No. QC-02-04
Date Revised 09-09-10
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9.0 SAMPLE HANDLING AND STORAGE: Not applicable
10.0 PROCEDURE AND ANALYSIS:

10.1	Summary: In this method, general growth media are exposed to the environment
to monitor the occurrence of airborne microorganisms (e.g., bacteria, mold and
yeast). This is a passive air sampling method. Petri plates containing TSA and/or
SDA are exposed to the environment for a specific period of time at various sites
in a laboratory (sample locations include bench tops, incubators and biosafety
cabinets etc). The uncovered plates are exposed to the environment for 15-60
minutes followed by incubation for 2 to 7 days. Following incubation, colonies
on the plates are counted and recorded.

10.2	The test can be performed on an as needed basis or at least once a year for all
laboratories.

10.3	Label TSA and /or SDA plates in accordance with their locations where they are
placed in a laboratory (room #, specific sites in a lab, etc).

10.4	Place the plates at desired locations and remove the covers sequentially at 15-30
second intervals.

10.5	Sequentially replace the covers after 15-60 minutes of exposure time. Record
exposure time on the Air Monitoring Record Form

10.6	Incubate the plates at 36±1°C (for TSA) or at 24±1°C (for SDA) for 2 to 7 days.
Plates can be wrapped in parafilm to prevent dehydration during extended period
of incubation (> 48 hrs). Plates may be observed daily for growth.

10.7 Count colonies and record the number of colonies per square foot. The
number of organisms which settle in 15 minutes of exposure on a petri dish is
equivalent to that for 1 sq. foot.

10.8 Presumptive identification of contaminants may be determined by use of Gram
stain and/or Vitek® analysis.

Note: It may be necessary to use a specific growth medium and incubation conditions if
one is attempting to identify the presence of a more fastidious microbe.

11.0 DATA ANALYSIS/CALCULATIONS:

11.1 Determine the number of CFUs per 15 x 100 mm plate (up to 300 CFU) per 15
minute period (or multiply with the factor if the exposure time is more than 15
minutes, e. g., the number of CFUs be multiplied with 2 if the exposure time is 30
minutes (Ref. 15.2).


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12.0 DATA MANAGEMENT/RECORDS MANAGEMENT:

12.1 Data will be recorded promptly, legibly and in indelible ink on the Air Monitoring
Record Form (see 16.0). Completed forms are archived in notebooks kept in
secured file cabinets in file room D217. Only authorized personnel have access to
the secured files. Archived data is subject to OPP's official retention schedule
contained in SOP ADM-03, Records and Archives.

13.0 QUALITY CONTROL:

13.1	The OPP Microbiology Laboratory conforms to 40 CFRPart 160, Good
Laboratory Practice Standards. Appropriate quality control measures are
integrated into each SOP.

13.2	For quality control purposes, the required information is documented on the
appropriate forms (see 16.0).

14.0 NONCONFORMANCE AND CORRECTIVE ACTION:

14.1	If contamination exceeds 15 colonies/plate/15 minute (Ref 15.2) or a laboratory
base line on the basis of past historical data, possible contamination sources will
be investigated. In order to minimize or remove the contamination source, the
laboratory will undergo a decontamination process that will consist of general
cleaning and the application of an antimicrobial product, if necessary, in specific
areas. Following this process, the air monitoring procedure will be repeated and
operation in a laboratory may be suspended until the problem is resolved.

14.2	If a plate that corresponds to a location inside a BSC demonstrates unacceptable
contamination (15 colonies/plate/15 minute or a laboratory base line on the basis
of past historical data), the BSC will not be used and the facility maintenance staff
will be informed of the situation. If necessary, decontamination procedures (e.g.
disinfectant application) will be conducted in the BSC. The monitoring test will
be repeated for the affected BSC. The BSC will not be used until the air
monitoring indicates acceptable level of microbial counts.

14.3	If any unusual air handling events take place (e.g., significant laboratory air flow
changes, construction within the facility), air monitoring may be conducted at any
time to verify the quality of the lab's air according to procedures in section 10.0
of this SOP (the test will be conducted only on the affected laboratory).

15.0 REFERENCES:

15.1 Bordner, R.H., Winter, J.A., & Scarpino, P.V., eds. 1978. Microbiological

Methods for Monitoring the Environment, Water, and Wastes. EPA 600/8-78-


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SOP No. QC-02-04
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017, Part IV Quality Assurance, U.S. Environmental Protection Agency,
Cincinnati, Ohio.

15.2 Eaton, A.D., Clesceri, L.S., Rice E. W. eds. 2005. Standard Methods for the

Examination of Water and Wastewater, (Page 9-4), 21st Edition. American Public
Health Association, American Water Works Association, Water Environment
Federation.

16.0 FORM AND DATA SHEET:

16.1 Air Monitoring Record Form


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SOP No. QC-02-04
Date Revised 09-09-10
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16.1 Air Monitoring Record Form

OPP Microbiology Laboratory

SOP QC-02 INFORMATION SHEET

Test Performed By: Date/Init.



Incubation Date and Time

Start:



Stop:

Exposure Time for Plates:

TSA Prep. No.: SDA Prep. No.:



Test Results Read By: Date/Init.

Location

TSA Plate

#

CFU/Plate

SDA Plate

#

CFU/Plate

Room

Site Description





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