ISO 8502-3 standard provides a standardized method for assessing the quantity and size of dust on steel surfaces prepared for painting using the pressure-sensitive tape method. ISO - International Organization for Standardization Current Standard Status The most current version of this standard is ISO 8502-3:2017 . While initially published in 2017, it was formally reviewed and confirmed in 2022
, ensuring it remains the active and operational standard for surface cleanliness assessment. Dust Assessment Classes The assessment is split into two primary metrics: Quantity Rating Size Class 1. Dust Quantity Rating
This is a qualitative visual comparison ranging from 1 to 5 based on pictorial references: Smallest amount of surface dust.
Highest quantity of surface dust (often looks like overall discoloration). iTeh Standards 2. Dust Particle Size Classes
Particles are classified by their diameter using a 10x magnifier: Description Typical Diameter No particles visible Visible under 10x magnification (not visible to naked eye) Just visible with normal vision Clearly visible with normal vision Clearly visible Clearly visible Assessment Procedure Preparation
: Discard the first three turns of the adhesive tape roll to ensure a clean sample. Application
: Press a 200 mm length of tape onto the prepared steel. Apply firm, consistent pressure (typically with a thumb or a calibrated spring-loaded roller Removal & Mounting : Peel the tape and place it on a contrasting display board or assessment plate. Comparison
: Compare the tape sample against the pictorial references in the ISO 8502-3 chart to determine the ratings. iTeh Standards Common Acceptance Criteria
The most current version of the ISO 8502-3 standard is ISO 8502-3:2017, which was last reviewed and confirmed in 2022 and remains the active version for 2026. It defines a qualitative "pressure-sensitive tape method" to assess dust quantity and size on blast-cleaned steel. ISO 8502-3 Dust Level Assessment
The standard uses two primary metrics to grade surface cleanliness: Quantity Rating (pictorial) and Size Class (descriptive). 1. Dust Particle Size Classes
The average size of the dust particles is assigned a class from 0 to 5 based on visibility and diameter: Particle Description Typical Diameter 0 No particles visible under 10x magnification 1 Visible under 10x magnification (not to naked eye) 2 Just visible with normal vision 50 μm – 100 μm 3 Clearly visible with normal vision Up to 0.5 mm 4 Clearly visible 0.5 mm – 2.5 mm 5 Clearly visible 2. Dust Quantity Ratings
The quantity of dust is assessed by comparing the tape to a pictorial reference chart (0–5 scale): Rating 0: Tape is clear; no dust visible. Rating 1–4: Increasing concentrations of dust particles. iso 85023 dust level chart pdf updated
Rating 5: Tape exhibits overall discoloration (reddish-brown/black), often caused by microscopic dust from specific abrasives. Standard Inspection Procedure
Understanding ISO 8502-3 Dust Level Chart
The ISO 8502-3 standard provides a method for assessing the cleanliness of surfaces in terms of dust and other contaminants. The standard is part of the ISO 8502 series, which focuses on the preparation of steel substrates before applying paints and related products.
What is the ISO 8502-3 Dust Level Chart?
The ISO 8502-3 dust level chart is a visual guide used to classify the dust levels on steel surfaces. The chart provides a reference for assessing the cleanliness of surfaces, which is crucial in ensuring the adhesion and performance of coatings.
Dust Levels According to ISO 8502-3
The ISO 8502-3 standard defines the following dust levels:
| Dust Level | Description | Visual Comparison | | --- | --- | --- | | A | No dust | No visible dust | | B | Light dust | A few small dust particles | | C | Medium dust | Some dust particles, but no continuous coverage | | D | Heavy dust | Continuous coverage of dust particles |
Updated Standards: What You Need to Know
The ISO 8502 series was updated in 2017, and the new standards bring some changes to the dust level classification. Here are the key updates:
ISO 8502-3:2017 Dust Level Chart PDF
You can find the updated ISO 8502-3:2017 standard and the dust level chart in PDF format on the International Organization for Standardization (ISO) website or through other online resources.
Key Takeaways
Download the ISO 8502-3:2017 PDF
You can download the ISO 8502-3:2017 PDF from the following sources:
Please note that you may need to purchase a copy of the standard or have a subscription to access the PDF.
The ISO 8502-3 standard provides a qualitative procedure for assessing dust on steel surfaces prepared for painting using the pressure-sensitive tape method. The most current version is ISO 8502-3:2017, which was last reviewed and confirmed in 2022 and remains the active standard. Understanding ISO 8502-3 Dust Levels
The standard evaluates two primary factors: the quantity of dust and the size of the dust particles. This assessment is critical because residual dust can severely reduce paint adhesion and promote corrosion by absorbing moisture. 1. Dust Quantity Ratings (0–5)
Quantity is determined by comparing the test tape to pictorial reference standards. INTERNATIONAL STANDARD ISO 8502-3
The ISO 8502-3 standard is a critical framework used in industrial coating to evaluate dust contamination on blast-cleaned steel surfaces. As of April 2026, the 2017 second edition remains the most current and widely referenced version, having technically revised and replaced the original 1992 standard. Core Assessment Mechanism
The standard utilizes a qualitative "pressure-sensitive tape method" to extract dust from a prepared surface and compare it against a standardized chart. 1. Dust Quantity Ratings (1–5)
Quantity is determined by visually comparing the dust on the tape to a pictorial reference chart. Rating 0: No dust detected, even under 10x magnification. ISO 8502-3 standard provides a standardized method for
Rating 1: Trace amounts; particles visible only under magnification. Rating 2: Dust barely visible to the naked eye. Rating 3: Particles clearly visible. Rating 4: Significant dust accumulation; easily noticeable. Rating 5: Heavy contamination. 2. Dust Size Classes (0–5)
While quantity impacts adhesion, particle size determines the "smoothness" and integrity of the first coating layer. INTERNATIONAL STANDARD ISO 8502-3
ISO 8502-3 Dust Deposit Assessment — Updated Guide & Dust Level Chart (PDF)
The chart displays actual-scale photographic examples of dust particles on a white background. For each quantity class, the chart shows typical particle sizes:
Key Insight from the updated chart: A "Class 3" dust level with fine particles (<100 µm) might be acceptable for a pipe coating in a dry climate, but the same Class 3 with coarse particles (300 µm) is an automatic failure for any high-performance coating.
ISO 8502-3 was last confirmed in 2023 (no technical changes). The 2017 edition is current. There is no 2024 or 2025 revision.
ISO 8502-3 Dust Level Chart is a standard visual tool used in the protective coatings industry to evaluate surface cleanliness after blast cleaning. The most current official version of the standard is ISO 8502-3:2017 , which replaced the original 1992 version. Электронный магазин стандартов Core Functionality
The chart provides a pictorial reference for the "Pressure-Sensitive Tape Method." Inspectors apply a specialized adhesive tape to a prepared steel surface, remove it, and then compare the captured dust against the chart to determine: iTeh Standards Dust Quantity Rating
: A scale from 0 to 5, where 0 is no visible dust and 5 is heavily contaminated. Dust Particle Size Class
: A classification from 0 to 5 based on the diameter of the largest particles. Rösler Group Updated Standard Features (ISO 8502-3:2017)
The 2017 update maintains the core visual comparison method but ensures consistency with other modern surface preparation standards. INTERNATIONAL STANDARD ISO 8502-3 The new standard introduces a more detailed classification