LOINCActiveObservation

LOINC Code 1607-1: Osmolality post 12 Hr fluid fast (U) [Osmolality]

1607-1 is a LOINC code used to identify Osmolality post 12 Hr fluid fast (U) [Osmolality] 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 Osmolality^post 12H FFst. It is commonly used with the system or sample type Urine.

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 Osmolality^post 12H FFst. It is commonly used with the system or sample type Urine.

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: Observation

What it does not mean

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

Key facts

  • Osmolality of Urine--12 hours post fluid fast
  • Osmolality^post 12H FFst
  • After; CHEMISTRY.CHALLENGE TESTING; Osmo; Osmol; Osmolality; osmolarity; p 12h FFST; Point in time; PST; QNT; Quan; Quant; Quantitative; Random; UA; UR; Urn

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

Osmolality post 12 Hr fluid fast (U) [Osmolality]Osmolality of Urine--12 hours post fluid fastOsmolality p 12h FFST UrOsmolality^post 12H FFstCHALOsmolality after 12 hr fluid fast, UrineOsmol

Frequently asked questions

Code details

Code1607-1
SystemLOINC
Display nameOsmolality post 12 Hr fluid fast (U) [Osmolality]
DescriptionOsmolality^post 12H FFst
Short nameOsmolality p 12h FFST Ur
ComponentOsmolality^post 12H FFst
PropertyOsmol
TimingPt
System (specimen)Urine
ScaleQn
ClassCHAL
Example unitsmmol/kg H2O;mOsm/L; mOsmol/kg
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0
Last changed2.40

Consumer names

Osmolality after 12 hr fluid fast, Urine

Part names

Osmolality^post 12H FFstOsmolPtUrineQnOsmolalityPoint 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 1607-1 | HealthAssure