Water Fluoride Laboratory Proficiency Testing Program
State Community Water System Split-Sample Programs
Operators of community water systems typically test water fluoride
content daily. To verify the accuracy of their testing method, they also
collect a sample, typically once every month, and split the sample into two
parts. One part of the sample is tested on site, and the other part is sent
to a state laboratory for verification testing. This comparison reveals if
the particular laboratory technique is correct and if the reported results
are accurate.
In its
Engineering and Administrative Recommendations for Water Fluoridation,
the CDC recommends that a state operate a split-sample program with the
water systems in its jurisdiction.
State Laboratory Proficiency Testing Program
All laboratories that measure fluoride should participate in a
proficiency testing program. Proficiency testing assesses a laboratory’s
performance in determining an accurate fluoride measurement against a known
standard sample. It is an essential quality-assessment methodology that
assures water fluoride levels are safe and properly monitored.
There are several references for proficiency testing, including:
- National Environmental Laboratory Accreditation Conference (NELAC)
2003 Standard for proficiency testing
- International Organization for Standardization (ISO) Guide 43–1
(1997): Proficiency testing by inter-laboratory comparisons
- A state-implemented certification program based on the Environmental
Protection Agency’s (EPA) Manual for the Certification of
Laboratories Analyzing Drinking Water.
Discontinuation of the CDC Proficiency Testing Program
In 1978, the national water fluoridation program was transferred from the
EPA to the CDC. At that time the CDC Division of Oral Health considered a
proficiency testing program to be a key CDC responsibility because there was
not another one in existence at that time.
CDC’s proficiency testing program operated from 1980–2009. EPA now
mandates that all laboratories participate in a state-based proficiency
program, or obtain certification from NELAC. This made the CDC proficiency
testing program redundant and it was discontinued in April 2009. Through the
new structure mandated by the EPA, state laboratories continue to have
reliable, accurate sources for verification testing.
Page last reviewed: August 24, 2009
Page last updated: August 24, 2009
Content source:
Division of Oral Health, National Center for Chronic Disease Prevention and
Health Promotion |
