ASTM D4579-00(2023)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D4579 − 00 (Reapproved 2023)
Standard Practice for
Handling an Acid Degreaser or Still
This standard is issued under the fixed designation D4579; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Significance and Use
1.1 This practice covers the procedures required for recog- 4.1 This practice describes the symptoms and causes of an
nizing and handling an acid vapor degreaser or still. acid degreaser as well as methods for correcting the problem.
1.2 If the degreaser(s) is equipped with a still, follow the 4.2 This practice is intended as a reference for use by
procedure in this practice for all of the equipment. persons responsible for the operation or maintenance of vapor
degreasers or stills.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4.3 This practice is not intended to cover every possible
responsibility of the user of this standard to establish appro-
situation.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. 5. Symptoms of an Acid Degreaser/Still
1.4 This international standard was developed in accor-
5.1 An acid condition in a vapor degreaser may be recog-
dance with internationally recognized principles on standard-
nized by one or more of the following symptoms:
ization established in the Decision on Principles for the
5.1.1 A strong acid odor.
Development of International Standards, Guides and Recom-
5.1.2 A dense white smoke in the vapor zone.
mendations issued by the World Trade Organization Technical
5.1.3 An unusually dark brown to black-colored solvent in
Barriers to Trade (TBT) Committee.
the degreaser sumps.
5.1.4 Dark spots and pitting of aluminum parts after
2. Referenced Documents
degreasing.
2.1 ASTM Standards:
5.1.5 Rusting of mild steel parts immediately after removal
D2110 Test Method for pH of Water Extractions of Haloge-
from the degreaser.
nated Organic Solvents and Their Admixtures
5.1.6 New formation of green deposits on copper condens-
D2942 Test Method for Total Acid Acceptance of Haloge-
ing coils or chiller coils.
nated Organic Solvents (Nonreflux Methods)
5.1.7 Newly formed blush rusting of stainless steel
D3698 Practice for Solvent Vapor Degreasing Operations
degreaser components, especially welded seams.
D4276 Practice for Confined Area Entry
5.1.8 Low pH of solvent as determined by Test Method
2.2 Federal Regulations:
D2110 by water extraction or a low acid acceptance of the
29 CFR 1910.146, Permit-Required Confined Spaces
solvent as determined by Test Method D2942, or both.
5.1.9 Severe pitting and corrosion inside water separator.
3. Terminology
3.1 Definitions:
6. Possible Causes of an Acid Degreaser
3.1.1 acid degreaser, n—an acid degreaser is the result of
6.1 It is rare for a solvent vapor degreaser to go acid when
the decomposition of the degreasing solvent to acid products.
properly operated and maintained. An acid degreaser can result
from any one or a combination of the following causes:
This practice is under the jurisdiction of ASTM Committee D26 on Haloge-
6.2 Lack of Proper Maintenance—If a degreaser is not
nated Organic Solvents and Fire Extinguishing Agents and is the direct responsi-
bility of Subcommittee D26.02 on Vapor Degreasing. cleaned out on a regular basis, the accumulations of soluble
Current edition approved Aug. 1, 2023. Published August 2023. Originally
and insoluble contaminants, especially reactive white metal
approved in 1986. Last previous edition approved in 2017 as D4579 – 00 (2017).
chips (for example, aluminum), can cause both thermal and
DOI: 10.1520/D4579-00R23.
chemical breakdown of the solvent resulting in the generation
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
of hydrochloric acid.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Available from U.S. Government Publishing Office, 732 N. Capitol St., NW,
Washington, DC 20401, http://www.gpo.gov. See also Practice D3698.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4579 − 00 (2023)
6.3 Deterioration of Heating Surfaces: use caustic soda (sodium hydroxide) or caustic potash (potas-
sium hydroxide) or other strong alkali, because an explosive
6.3.1 Damaged Heating Elements—Deterioration of either
product may result.
gas or electrical heating elements can cause arcing or hot spots
resulting in an acid condition of the solvent. The deterioration
8. Recommended Procedure for Cleaning an Acid
may be due to damage, corrosion or accumulation of contami-
Degreaser
nants on the heating surface.
6.3.2 Exposed Heating Surfaces—Exposure of gas and elec-
8.1 Make sure enough soda ash solution is present in the
tric heating surfaces to the air can cause solvent decomposi-
degreaser to prevent solid residue from being exposed to air
tion. Heating elements exposure is caused by a low solvent
when the solvent is pumped out of the machine. (The water
level that is not detected by low liquid level controls.
solution floats on top of the solvent.) Pump the acid solvent
into steel drums containing about one pound of soda ash. Care
6.4 Excessive Amounts of Water—Hydrolysis of certain
should be taken to remove all solvent from water separators,
solvents and impurities can be a factor in the formation of an
pumps etc. Do not insert the bungs in the drums until
acid condition. Free water can also remove stabilizer.
neutralization reaction is complete. (Carbon dioxide is formed
6.5 Chlorinated and Sulfonated Oils—Some chlorinated and
by the neutralization reaction. If sealed, pressure from the
sulfonated oils used in deep drawing processes begin to break
evolution of carbo
...