LOINCActiveBoth

LOINC Code 43158-5: Chlorine.free (Water) [Mass/Vol]

43158-5 is a LOINC code used to identify Chlorine.free (Water) [Mass/Vol] in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Chlorine.free. It is commonly used with the system or sample type Water.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Chlorine.free. It is commonly used with the system or sample type Water.

When is it used?

  • Used in lab systems, EHRs, and clinical data exchange.
  • May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
  • Status: ACTIVE
  • Order vs observation: Both

What it does not mean

  • The code identifies the observation or test, not the actual result.

Key facts

  • Chlorine.free [Mass/volume] in Water
  • Chlorine.free
  • Chlorine Free; Cl2; DRUG/TOXICOLOGY; Drugs; FR; Level; Mass concentration; Non-protein bound; Point in time; QNT; Quan; Quant; Quantitative; Random; Wat

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Chlorine.free (Water) [Mass/Vol]Chlorine.free [Mass/volume] in WaterChlorine Free Wat-mCncChlorine.freeDRUG/TOXFree chlorine, WaterMCnc

Frequently asked questions

Code details

Code43158-5
SystemLOINC
Display nameChlorine.free (Water) [Mass/Vol]
DescriptionChlorine.free
Short nameChlorine Free Wat-mCnc
ComponentChlorine.free
PropertyMCnc
TimingPt
System (specimen)Water
ScaleQn
ClassDRUG/TOX
Example unitsmg/L
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.16
Last changed2.34

Consumer names

Free chlorine, Water

Part names

Chlorine.freeMCncPtWaterQnMass ConcentrationPoint in time (spot)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

LOINC Code 43158-5 | HealthAssure