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Fluoride Test (FLR) — Deprecated

Published: August 9, 2026Updated: August 16, 2026

A legacy fluoride test historically used to assess fluoride exposure or monitor treatment. This test entry is marked as deprecated.

Quick summary

["Fluoride testing can help evaluate exposure to fluoride, but the listed test is outdated and should be confirmed with the ordering laboratory."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
30835-3
Short code
Deprecated Flr
Synonyms
Deprecated Flr
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
xr-fluor
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

This is a test for measuring fluoride in a patient specimen. The listed test is marked as deprecated, meaning it is an older or retired test entry and may not be the same assay currently used by laboratories.

Why might I need this test?

Fluoride testing has historically been used to evaluate fluoride exposure and to monitor treatment for people with excessive fluoride levels. A clinician may order a newer version of this test instead.

How is the test performed?

A laboratory specimen is analyzed with a method designed to measure fluoride. Because this entry does not identify the specimen type or analytical method, the ordering laboratory should provide those details.

How do I prepare for the test?

Follow the preparation instructions provided by the clinician or laboratory. Do not fast or stop medicines unless you are specifically told to do so.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

An elevated fluoride result may indicate recent exposure, ongoing environmental exposure, or intake of too much fluoride. A low result is less commonly a concern but can occur with low fluoride intake or certain dietary circumstances. Interpretation depends on the specimen, timing, and laboratory method used.

Short name

Fluoride test

Frequently asked questions

Is the deprecated fluoride test still available?
Availability varies by laboratory, and many have replaced it with a newer assay. Ask the ordering clinician or laboratory whether the current test has a different name or specimen requirement.
Why was this test entry deprecated?
Deprecated entries are older, retired, or replaced by newer laboratory tests. This does not mean that measuring fluoride is no longer useful; it means the listed test should be confirmed before it is ordered.
Can I interpret an old fluoride result myself?
No. Ask the ordering clinician to interpret the result because fluoride levels can be affected by the specimen type, collection time, recent exposure, and analytical method.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy