For compliance in 2026, it is vital to use the updated pictorial standards. While the standards themselves are proprietary, several sources offer compliant charts or interpretation guides.
Proper surface preparation is the single most critical factor in determining the longevity of a protective coating. The standard provides the definitive qualitative method—known as the Dust Tape Test —for assessing the presence of loose dust on blast-cleaned steel surfaces before painting.
ISO 8502-3:2017 describes a qualitative test method for assessing dust remaining on cleaned steel surfaces prepared for painting. The method is applicable to steel surfaces that, before cleaning, corresponded to rust grades A, B, or C as defined in ISO 8501-1. The standard can be used either as a "pass/fail" test by comparison with specific limits or to provide a permanent record of the dust present on a surface by mounting the used tapes on tiles, cards, or paper. iso 85023 dust level chart pdf updated
Very heavy dust level; the tape surface is nearly or completely covered by dust. 2. Dust Size Class (Class 1 to 5)
Very high dust level; dense concentration covering the entire tape area. For compliance in 2026, it is vital to
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
Compare the tape against the pictorial reference chart to determine the quantity and size rating. Where to Find the Updated ISO 8502-3 Dust Level Chart PDF The standard can be used either as a
Painting schedules and coating specifications typically require that shot-blasted surfaces prior to painting be free of dust. A generally accepted industry rule stipulates that of ISO 8502-3.
| | Description | Typical Application | |---|---|---| | Class 1 | Dust particles visible only under magnification (≤ 10x). No particles visible to the naked eye. | High-performance coatings (epoxy, polyurethane) for aggressive environments. | | Class 2 | Dust particles visible to the naked eye but not densely distributed. Moderate dust quantity. | General industrial environments. | | Class 3 | Dust layer clearly visible, dense distribution of particles. | Low-performance coatings or non-critical areas (rarely accepted). |
The standard evaluates two primary factors: the 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)
A: It is designed primarily for blast-cleaned steel (corresponding to rust grades A, B, or C).
