The standard provides a qualitative and quantitative framework: It classifies the size of the dust particles.
While official ISO standards must be purchased directly from ISO or national bodies, updated PDF summary charts allow field inspectors to quickly reference specifications on tablets and smartphones without carrying bulky paper manuals into confined spaces.
It is a based on a "tape test". The dust particles are removed from the surface using a special adhesive tape and transferred to a comparison chart (the dust level chart ) to determine the dust rating.
Severe contamination; tape is fully covered or shows overall discoloration. Severe Failure
ISO 8502-3 is a globally recognized standard that defines a method for assessing the quantity and size of dust particles remaining on blast-cleaned steel surfaces prior to painting. iso 85023 dust level chart pdf updated
Heavy dust coverage, coating application should not proceed. 2. Particle Size Classes (0–5) The average particle size is designated by a class: Size 0: Particles invisible to the naked eye (microscopic).
💡 If the adhesive tape displays an overall, fine discoloration (often reddish-brown from mineral abrasives or black from slag), it indicates an abundance of microscopic dust particles under
Ranging from very fine particles to large, coarse particles clearly visible without magnification. How to Perform an ISO 8502-3 Dust Test
Performing a dust assessment according to ISO 8502-3 requires specific equipment: The dust particles are removed from the surface
The following outlines the complete procedure for conducting an ISO 8502-3 dust assessment:
To execute a compliant test, standard kits like the or the DeFelsko PosiTest DT are used.
ISO 8502-3 defines a qualitative field test to assess the average quantity and size of dust particles remaining on steel surfaces before painting. Dust accumulates naturally from abrasive blasting media, environmental fallout, or nearby grinding work.
Performing the test accurately requires specific equipment and a strict adherence to the methodology to ensure reproducible results. Required Equipment Heavy dust coverage, coating application should not proceed
: Particles clearly visible with normal vision, ranging from in diameter [1.19]. Class 4 : Particles ranging between in diameter [1.19]. Class 5 : Large debris particles greater than in diameter [1.19]. Step-by-Step ISO 8502-3 Test Procedure
Direct you to suppliers for the Elcometer 142 Dust Assessment Plate.
: Particles visible with normal vision but less than 0.5 mm in diameter.
Press approximately 150 mm (6 inches) of the freshly exposed tape firmly onto the surface to be tested, touching the adhesive side only at the ends. Place the thumb across one end of the tape and move the thumb along the tape at a constant speed and pressure. Repeat this motion three times in each direction, with each stroke taking approximately 5 to 6 seconds.
Low density. Particles are visible to the naked eye but cover a minimal percentage of the surface area.