Chloride Sampling Procedure Following Fire Damage

Oct 15, 2026 | Technical Articles

The Chloride test following fire damage is simple enough using a Fire Damage Chloride Test kit. However, it is very important to pay attention to the collection of the sample as contamination and procedural errors can substantially affect the result.

Chloride contamination is common and can cause significant false positives in your test e.g. not washing your hands after eating a bag of crisps and then handling the gloves.

The key aspects of correct sample collection are as follows:

  1. Ensure you wear new uncontaminated gloves throughout the procedure.
  2. Ensure you are ready with a new unused swab fresh from the packet or Ziplock bag for each sample.
  3. Clean template prior to use as it has been placed previously on a contaminated area.
  4. Thoroughly swab the entire area inside the template and ensure the swab is placed inside the beaker containing the ISAB (Ionic Strength Adjustment Buffer)
  5. Ensure you mix the swab/ISAB very thoroughly and allow time for the chloride to migrate into the solution.
  6. Once you record the result on the spreadsheet provided make sure you have performed a corresponding BLANK test which is subtracted from the test result.

The operation of the Meter and probe are covered in the manual for the kit.

This sampling procedure is focused on ensuring good practise during the preparation of the sample.

Step by step guide to sampling for the Fire Damage Chloride Test:

  • Put on a clean pair of gloves prior to sampling
  • Syringe 20ml of ISAB into the clean 100ml beaker provided
  • Take a clean swab from the packet and syringe 0.5ml of ISAB from the beaker onto the folded swab and allow to absorb. Using a previously wetted swab increases the diluent volume and gives a lower result
  • Place the clean template onto the sample area
  • Whilst holding the template swab the area thoroughly. Fold the swab periodically to expose a clean swab surface to the sample area. Make sure not to squeeze the swab too hard to prevent losing any drops of ISAB
  • When the area is clean place the entire swab into the beaker containing the 20ml ISAB
  • Using the stirrer provided, making sure not to lose any sample, thoroughly mix and submerge the swab. Continue this for around 30 seconds and then leave to stand for around 2 minutes
  • Rinse the Chloride electrode with ISAB, Dab dry with a tissue and place the probe in the beaker. Stir the sample with the probe one final time and leave to stand
  • Press READ to start the measurement

Taking and recording a Blank Measurement:

A blank is recorded to eliminate the inherent background Chloride that may reside in the components of the test e.g. the swab or the atmosphere around the sample etc.

The preparation is simple:

  • Syringe 20ml of ISAB into the beaker provided
  • Place a new swab into the beaker and stir thoroughly. Continue this for 30 seconds and then leave to stand for 2 minutes
  • Measure using the Chloride Electrode and record the result on the spreadsheet provided
Purchase The Kit Here

Before attending a new site ensure the kit components are cleaned with deionised water and that the gloves are disposed of and the swabs are resealed in their packet.