SMILE
Johns Hopkins University
Baltimore, MD USA
Water Quality - Guidelines
Water Quality Manual
Guideline Number
Fac30-02-G
Effective Date
12/6/06
Page
1 of 2
Supersedes
New
Review Date
25 Jan 2012
Subject
Water Quality Guidelines
Review by
Heidi Hanes
SMILE Comments: This document is provided as an example only. It must be revised to accurately reflect your lab’s
specific processes and/or specific protocol requirements. Users are directed to counter check facts when considering
their use in other applications. If you have any questions contact SMILE.
Audit:
Questions pertaining to water quality can be found in Test and Control Articles Section.
CAP Accreditation Checklist:
Questions pertaining to water quality can be found in the Quality of Water and Glassware
Washing section of the CAP Accreditation Laboratory General Checklist.
Background Information:
Reagents grades are defined by CLSI Guideline C3-A4 as follows:

Clinical Laboratory Reagent Water (CLRW)

Special Reagent Water (SRW)

Instrument Feed Water

Water Supplied by a method manufacturer for use as a diluent or reagent

Commercially Bottled, purified water

Autoclave and wash water applications
CLRW should be pure enough to satisfy the requirements of most routine clinical laboratory
testing. This type of water is usually used for the reconstitution of controls and reagents and
with instruments using water for analysis. The requirement for microbial content, resistivity,
Total Organic Content (TOC) and particulate matter are the same as Type I.
SRW is used in testing that requires different purity other than CLRW. This could include
different levels of CO2, trace metals, or organic impurities.
Instrument Feed Water is intended for internal rinsing, dilution and water bath functions of
automated instruments. The specification of this type of water must be confirmed with the
manufacturer of a specific instrument.
Water supplied by a method manufacturer for use as a diluent or reagent. This type of
water must only be used as described by the product labeling for that system. This type of
water can not be used for CLRW or SRW unless it meets those specific requirements.
Commercially bottled, purified water must meet the required specifications for its intended
use. The water should be packaged in a manner that protects it from environmental
contamination or degradation during transportation and storage, and from the effects of the
container itself. Note that any bottled water, no matter what type, must include a lot number and
Fac3.0-02 Water Quality SOP
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Johns Hopkins University
Baltimore, MD USA
expiration date as well as the values for resistivity, microbial count, TOC and information on
particulate control in addition to any other applicable parameters. Commercially bottled purified
water may have met the specification for CLRW when bottled, but at use, the bottled water
should be considered SRW with specifications set by the laboratory based on intended use. The
laboratory must validate that the bottled water is fit for its intended purpose in clinical laboratory
testing. If a bottle is opened and reused over a period of time, the laboratory must validate the
water remaining in the bottle as fit for its purpose throughout the entire period of use. Each new
lot of bottled water must be validated for acceptable performance in the test procedures for
which it will be used. Validations must include chemical, microbial and particulate quality
requirements of purified water. Once validated, the acceptability of purified water should be
monitored to ensure it continues to be fit for its intended purpose
Autoclave and wash water application water is intended for use as feed water for autoclaves
and for automatic laboratory dishwashers with heat drying cycles. It is purified to low level of
inorganic, organic and particulate impurities that otherwise could contaminate solutions and
media in an autoclave or remain on washed laboratory ware. This was previously referred to as
Type III water. There is no consensus to specification of this type of water.
Previous definition of water is listed below:
Maximum microbial content (CFU/mL)
Minimum resistivity (megohm-cm)MΩ-cm
Maximum silicate content (mg/L
SiO2)*(TOC)
Particulate matter
Type I
≤10
≥10 (in-line)
≤0.05
Type II
≤1000
≥1.0
≤0.1
n/a
≥0.1
≤1.0
Type III
≤0.22 um filter
n/a
n/a
CAP minimum monitoring requirement includes periodical testing of resistivity and microbiology
cultures. The frequency should be enough and the results trended to detect changes and
anticipate maintenance problems. Each laboratory must determine how often to measure the
parameters of its purified water and purification system. Silicate content must be done initially
to determine if high concentration are present in the source water. Other criteria such as pH,
particulate matter, organic contamination is at the discretion of the laboratory.
In the new water listing Type I and II are the same as CLRW depending on the content
requirement and Type III is similar to autoclave and wash water applications.
Resistivity is an indicator of ionic contamination. It is inversely related to ionic content. The
higher this value the better the water quality. It is usually reported in megohm-centimeters (MΩcm).
Resources
1. Clinical Laboratory Standards Institute (CLSI). Preparation and Testing of Reagent
Water in the Clinical Laboratory: Proposed Guideline – Fourth Edition. CLSI Document
C3-A4 Vol 26 No 2 (ISBN 1-56238-610-7). Clinical and Laboratory Standards Institute,
Wayne, PA
2. College of American Pathologists (CAP) 2006. Commission on Laboratory
Accreditation, Laboratory Accreditation Program; Laboratory General Checklist Revised
4/6/2006.
Fac3.0-02 Water Quality SOP
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Water Quality - Policy
Water Quality Policy
Approval Signature: Laboratory Director
Policy Number
Fac30-02-P
Effective Date
12/6/06
Review Cycle
1 year
Supersedes
New
Policy
The laboratory has processes and procedures to effectively ensure that all
water used in the laboratory meets the correct standards for laboratory
testing.
Purpose
This policy provides direction for the processes and procedures to
effectively ensure that all water used in the laboratory meets the correct
standards.
Responsibility
The Laboratory Medical Director is responsible for
The Laboratory Manager is responsible for
The Lead Technologists are responsible for
Clinical Laboratory
Reagent Water (CLRW)
The type of water used for most routine clinical laboratory testing will meet
requirements for microbial content, resistivity, Total Organic Content and
particulate matter.
Instrument Feed Water
Water used for internal rinsing, dilution and water bath functions of
automated instruments will be according to specification by the
manufacturer of the specific instruments.
Water Supplied by a
The type of water supplied by a method manufacturer for use as a diluent
method manufacturer for or reagent will only be used as described by the product labeling for that
use as a diluent or
system.
reagent
Commercially Bottled,
purified water
Each new lot of commercially bottled purified water will be validated for
acceptable performance to include chemical, microbial and particulate
quality requirements of purified water.
Autoclave and wash
water applications
Water used as feed water for autoclaves and automatic laboratory
dishwashers with heat drying cycles is purified to low level of inorganic,
organic and particulate impurities to prevent contamination of solutions
and media in the autoclave and washed laboratory ware.
Supporting Documents
The following processes support this policy:
Fac3.0-02 Water Quality SOP

Water provided in-house

Water provided by vendors
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Water Quality – Process
Water Quality Process
Process Number
Fac30-02-Pro
Effective Date
12/6/06
Review Cycle
1 year
Supersedes
New
Approval Signature: Laboratory Director
Process for water provided in-house
Start
SOP is reviewed
for type of water
required
Process of
Vendor
supplied
water
NO
Water
provided
in-house ?
YES
Water is
checked for
quality
Who’s Responsible
What Happens
Type of water is determined

Lead Technologist
Water is checked for quality

QA Technologist

Fac3.0-02 Water Quality SOP
End
Instructions
Technical SOPs
Water Quality SOP
Technicians/Technologists
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Process for water provided by Vendors
Start
Commercial Water
is received in the
laboratory
Validate
acceptability
for
laboratory
use
Laboratory
information is
documented
No
Used for
diluent
?
Label and
Store Water
Yes
What Happens
Who’s Responsible
End
Instructions

Hospital receiving
Dept

Laboratory Stock Clerk
Label information is
documented

Laboratory Stock Clerk
Logging in water supplied by
outside vendors.
Specifications for laboratory
use are checked

QA Technologist
Specifications for laboratory
grade water in laboratory
testing
Water is labeled.

Laboratory Stock clerk
Labeling of Laboratory
Reagents
Water is stored.

Laboratory Stock Clerk

Laboratory
Technicians/Technolo
gists
Storage of Laboratory
Reagents
Commercially supplied water
is received in the laboratory
Fac3.0-02 Water Quality SOP
Version#: 1.0
Receiving Commercially
Prepared Water in the
Laboratory.
Page 5 of 13
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Water Quality - SOP
Author(s), Name &
Title
Heidi Hanes
Document
Number
Effective
Date
International QA/QC Coordinator
Fac30-02-SOP
14-Dec-06
SMILE Comments: This document is provided as an example only. It must be revised to accurately
reflect your lab’s specific processes and/or specific protocol requirements. Users are directed to counter
check facts when considering their use in other applications. If you have any questions contact SMILE.
Name, Title
Signature
Date
Name, Title
Signature
Date
Approved
By
SOP
Annual
Review
Version # [0.0]
Revision Date
[dd/mm/yy]
Description (notes)
Revision
History
Name (or location)
# of copies
Name (or location)
# of copies
Distributed
Copies to
Associated Forms:
Fac3.0-02 Water Quality SOP
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Name (print)
Signature
Date
I acknowledge that I have read, understand and agree to follow this SOP.
Fac3.0-02 Water Quality SOP
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Purpose
This procedure is to assure that all water used in the laboratory is of the correct standard for
testing. The laboratory must define the type of water necessary for each of its procedures. This
is based upon requirements for specific tests, procedures, instrumentations or laboratory. The
laboratory should have an adequate supply of needed water.
(This statement should be revised to include the type of water necessary. It should state the
specifications needed for laboratory use.)
Pre-analytic Procedure
Refer to the following procedures:






Patient Preparation
Specimen Collection
Safety
Specimen Handling
Specimen Storage
Enter other basic procedures needed for your lab.
The exceptions to these procedures are listed below:


Enter exceptions to the procedures listed above that are needed for this procedure.
Or NA
Analytic Procedure
Specimen Information: NA
Reagents/Media: NA
Supplies:

Resistivity meter

pH meter

Clean container to hold water
Equipment Calibration/Maintenance:
I. Daily Checks:
Step
1
Fac3.0-02 Water Quality SOP
Action
Check all indicator lights on the system. (Some systems have
lights indicating whether the system is on or off, if the filters are
within specific limits, etc.)
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2
3
II.
If
Then
Lights are not correct
Follow steps to correct.
(Innumerate steps to take.)
Check connections, pipes, hoses, etc. for leaks.
If
Then
Leaks found
Follow steps to correct.
(Innumerate steps to take.)
Check and record pressure level for gauges. (Some systems
have pressure gauges that need to be within specific ranges.)
If
Then
Outside acceptable
ranges.
Follow steps to correct.
(Innumerate steps to take.)
4
Record all required information in the log.
5
If there are any issues, report all problems to the supervisor.
Monthly Maintenance
(Monthly maintenance requirements are defined by the manufacturer. Below
are some examples, modify as needed.)
A.
Change filters.
(Some systems contain filters that need periodical changing according
to the manufacturer’s requirements.)
Step
III.
Action
1
Describe location of filter.
2
List steps to perform.
3
List steps if problems occurs.
Quarterly Maintenance
(Maintenance requirements are defined by the manufacturer.)
List the procedure for any required maintenance.
IV.
Preventative Maintenance.
(Maintenance requirements are defined by the manufacturer.)
List the procedures for preventative maintenance.
Quality Control: NA
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Test Method Instructions:
If your water system does not have a built –in meter to measure resistivity follow
steps below. If it does have a built in meter follow steps in Alternate A.
A. Follow the steps in the table below to check the resistivity.
(The acceptable range depends on water type. The higher the number, the better the
water quality.)
Step
Action
1
Turn the resistivity meter on and allow it to warm up for 5
minutes before use.
2
Obtain at least 50 ml of water to be tested in a clean container.
3
Place resistivity probe in the water up to the testing line.
4
Record the reading in the log and repeat 4 more times.
5
Do not discard water. Use the same aliquot for determining pH
(if necessary).
6
If
Then
Outside acceptable
ranges.
Follow steps to correct.
(Innumerate steps to take.)
A. Alternative:
Step
Action
1
2
Record on log.
If
Then
Outside acceptable ranges.
Follow steps to correct. (Innumerate
steps to take.)
B. Follow the steps in the table below to check the pH, if necessary.
(Checking of pH may be necessary if the pH will affect the testing, such as in staining
procedures.)
Fac3.0-02 Water Quality SOP
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Johns Hopkins University
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Step
Action
1
Use the same 50 ml aliquot of water used to determine
resistivity. If used Alternate A draw off 50 ml aliquot.
2
Turn on pH meter and allow it to warm up for 5 minutes before
use.
3
Place pH probe in the water up to the testing line.
4
Record the reading in the log and repeat 4 more times.
5
Discard water.
6
If
Then
Outside acceptable
ranges.
Follow steps to correct.
(Innumerate steps to take.)
C. Follow the steps in the table below to check for microorganisms.
Step
Action
1
List sample collection procedures.
2
List sample submission instructions and contacts.
3
Record on log
4
5
If
Then
Outside acceptable ranges.
Follow steps to correct.
(Innumerate steps to take.)

Retest water source.

Take questionable
water source out of use
until retesting is
completed.

If it continues to be
outside acceptable
range, contact
manufacturer.
File microbiology reports.
Calculations: NA
Expected Values:
The various water types used in the lab should have the following readings:

Glassware cleaning
o
Resistivity: >1.5
Fac3.0-02 Water Quality SOP
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
o
pH: 6.5 – 7.5
o
Microbial content: NA
Chemistry analyzer
o
Resistivity: >10.5
o
pH: 6.7 – 7.3
o
Microbial content: <7CFU/ml
Interpretation of Results: NA
Method Limitations: NA
Post-analytic Procedure
How are Results Prioritized: NA
Result Entry into Lab Reporting System: NA
Notification of Result to Appropriate Personnel: NA
Archiving Results and Report Documents: NA
Specimen Retention: NA
References: List sources of information such as instrument manuals that may assist with the
procedure.
1. Clinical Laboratory Standards Institute (CLSI). Preparation and Testing of Reagent
Water in the Clinical Laboratory: Proposed Guideline – Fourth Edition. CLSI Document
C30A4 Vol 26 No 2 (ISBN 1-56238-610-7). Clinical and Laboratory Standards Institute,
Wayne, PA
2. Clinical Laboratory Standards Institute (CLSI). Clinical Laboratory Technical Procedure
Manuals; Fourth Edition. CLSI Document GP2-A4 (ISBN 1-56238-458-9). Clinical and
Laboratory Standards Institute, Wayne, PA
Appendices: Attach supporting documents such as package inserts, forms, log sheets or
charts.
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A.
Water Quality Maintenance Log
(Attached is a sample log sheet. Adjust form according to laboratory needs and
standards.)
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