ASTM G85-19 PDF

Full title and description

ASTM G85-19 — Standard Practice for Modified Salt Spray (Fog) Testing. This practice defines five modified salt spray (fog) test methods (annexes) that create more aggressive or specialized corrosive environments than the conventional salt fog practice, for evaluation and specification of metals and coatings under accelerated corrosive exposure.

Abstract

ASTM G85-19 provides standardized procedures and control conditions for five modifications of salt spray (fog) testing (Annexes A1–A5) including continuous acetic acid-salt spray, cyclic acidified salt spray, seawater acidified cyclic (SWAAT), SO2 salt spray cyclic, and a dilute electrolyte cyclic fog/dry test. The practice specifies apparatus requirements, spray solutions and compositions, cycle timing, temperature and humidity ranges, and guidance for test execution while noting that it does not prescribe pass/fail criteria or interpretation for specific products.

General information

• Status: Active (current edition published 2019).
• Publication date: Approved November 1, 2019; published December 2019 (2019 edition designated G85-19).
• Publisher: ASTM International.
• ICS / categories: Corrosion of metals — ICS code 77.060 (laboratory corrosion tests).
• Edition / version: G85-19 (2019). DOI reference appears in the official document.
• Number of pages: 14 pages (official PDF/document summary).

Scope

This practice covers and sets forth conditions for five modifications in salt spray (fog) testing for specification purposes—Annex A1 (acetic acid-salt spray, continuous), Annex A2 (cyclic acidified salt spray), Annex A3 (seawater acidified cyclic, SWAAT), Annex A4 (SO2 salt spray, cyclic), and Annex A5 (dilute electrolyte cyclic fog/dry). It is applicable to ferrous and nonferrous metals and to organic and inorganic coatings, and is intended to provide controlled, repeatable accelerated exposures; it does not prescribe interpretation or acceptance criteria for specific products.

Key topics and requirements

• Descriptions of five modified salt spray methods (A1–A5) and when they are used.
• Apparatus requirements: fog chamber, solution reservoir, atomizing nozzle(s), conditioned compressed air supply, specimen supports, chamber heating and control provisions; cabinet materials must not affect fog corrosiveness.
• Spray solutions and compositions — e.g., the SWAAT (Annex A3) solution synopsis indicates ~42 g synthetic sea salt plus 10 mL glacial acetic acid per litre and target pH and salinity control procedures.
• Environmental control parameters: temperature set points and tolerances, fog (spray) deposition rates (typical guidance 1.0–2.0 mL/h per 80 cm2), humidity and cycle timing for cyclic tests, and wet-bottom vs dry-bottom configurations as specified in respective annexes.
• Procedures for introduction of gases where required (for example SO2 dosing cycles in Annex A4) and for establishing cyclic spray/soak/dry sequences.
• Reference to related ASTM practices and specifications for solution salts and water quality (for example Practice D1141 for synthetic seawater and Practice D1193 for reagent water) used in preparing spray solutions.

Typical use and users

Laboratory technicians and corrosion engineers in testing laboratories, coatings and metal manufacturers, OEMs, specification writers, procurement and quality departments, and government/military agencies use G85-19 to define and perform accelerated modified salt spray exposures for product development, qualification, and comparative evaluations. The practice is recognized for specification purposes and has been approved for use by certain government agencies.

Related standards

Commonly referenced standards include ASTM B117 (Standard Practice for Operating Salt Spray (Fog) Apparatus), ASTM D1141 (Practice for the Preparation of Substitute Ocean Water), ASTM D1193 (Specification for Reagent Water), and other ASTM corrosion and coating test methods referenced within the annexes and apparatus sections.

Keywords

modified salt spray, salt fog, SWAAT, acetic acid-salt spray, cyclic acidified salt spray, SO2 salt spray, dilute electrolyte cyclic fog/dry, corrosion testing, accelerated corrosion, coatings evaluation.

FAQ

Q: What is this standard?

A: ASTM G85-19 is a practice that specifies procedures and control conditions for five modified salt spray (fog) tests used to produce more aggressive or specialized corrosive exposures than the basic salt fog practice.

Q: What does it cover?

A: It covers apparatus, spray solutions and their preparation, environmental parameters (temperature, humidity, fog deposition rate), cycle timing for cyclic tests, and specific modifications described in Annexes A1–A5; it does not set pass/fail criteria for products.

Q: Who typically uses it?

A: Test labs, corrosion and coatings engineers, manufacturers, OEMs, procurement/quality teams, and government or defense agencies that require standardized accelerated corrosion exposures for material and coating evaluation.

Q: Is it current or superseded?

A: The 2019 edition (G85-19) is the current published edition (approved November 1, 2019; published December 2019). The practice is subject to periodic review (ASTM standards are reviewed at least every five years). Users should confirm whether a newer revision has been issued since 2019 before citing it for new procurements or specifications.

Q: Is it part of a series?

A: It is part of ASTM Committee G01's corrosion test practices and is commonly used alongside Practice B117 and other ASTM corrosion/coating standards; it provides alternative (modified) salt spray methods rather than forming a numeric series.

Q: What are the key keywords?

A: Modified salt spray, salt fog, SWAAT, acetic acid-salt spray, cyclic acidified, SO2 spray, dilute electrolyte cyclic fog/dry, corrosion testing, coatings evaluation.