ASTM D4579-00(2006)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D4579–00(Reapproved2006)
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 4.2 This practice is intended as a reference for use by
persons responsible for the operation or maintenance of vapor
1.1 This practice covers the procedures required for recog-
degreasers or stills.
nizing and handling an acid vapor degreaser or still.
4.3 This practice is not intended to cover every possible
1.2 If the degreaser(s) is equipped with a still, follow the
situation.
procedure in this practice for all of the equipment.
1.3 This standard does not purport to address all of the
5. Symptoms of an Acid Degreaser/Still
safety concerns, if any, associated with its use. It is the
5.1 An acid condition in a vapor degreaser may be recog-
responsibility of the user of this standard to establish appro-
nized by one or more of the following symptoms:
priate safety and health practices and determine the applica-
5.1.1 A strong acid odor.
bility of regulatory limitations prior to use.
5.1.2 A dense white smoke in the vapor zone.
2. Referenced Documents 5.1.3 An unusually dark brown to black-colored solvent in
the degreaser sumps.
2.1 ASTM Standards:
5.1.4 Dark spots and pitting of aluminum parts after
D2110 Test Method for pH of Water Extractions of Halo-
degreasing.
genated Organic Solvents and Their Admixtures
5.1.5 Rusting of mild steel parts immediately after removal
D2942 Test Method for Total Acid Acceptance of Haloge-
from the degreaser.
nated Organic Solvents (Nonreflux Methods)
5.1.6 New formation of green deposits on copper condens-
D3698 Practice for Solvent Vapor Degreasing Operations
ing coils or chiller coils.
D4276 Practice for Confined Area Entry
5.1.7 Newly formed blush rusting of stainless steel
2.2 Federal Regulations:
degreaser components, especially welded seams.
29 CFR 1910.146, Permit-Required Confined Spaces
5.1.8 Low pH of solvent as determined by Test Method
3. Terminology
D2110 by water extraction or a low acid acceptance of the
solvent as determined by Test Method D2942, or both.
3.1 Definition:
5.1.9 Severe pitting and corrosion inside water separator.
3.1.1 acid degreaser, n—an acid degreaser is the result of
the decomposition of the degreasing solvent to acid products.
6. Possible Causes of an Acid Degreaser
4. Significance and Use
6.1 It is rare for a solvent vapor degreaser to go acid when
properly operated and maintained.An acid degreaser can result
4.1 This practice describes the symptoms and causes of an
from any one or a combination of the following causes:
acid degreaser as well as methods for correcting the problem.
6.2 Lack of Proper Maintenance—If a degreaser is not
cleaned out on a regular basis, the accumulations of soluble
and insoluble contaminants, especially reactive white metal
This practice is under the jurisdiction of ASTM Committee D26 on Haloge-
chips (for example, aluminum), can cause both thermal and
nated Organic Solvents and Fire Extinguishing Agents and is the direct responsi-
chemical breakdown of the solvent resulting in the generation
bility of Subcommittee D26.02 on Vapor Degreasing.
Current edition approved Jan. 1, 2006. Published February 2006. Originally of hydrochloric acid.
approved in 1986. Last previous edition approved in 2000 as D4579 – 00. DOI:
6.3 Deterioration of Heating Surfaces:
10.1520/D4579-00R06.
6.3.1 Damaged Heating Elements—Deterioration of either
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
gas or electrical heating elements can cause arcing or hot spots
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
resulting in an acid condition of the solvent. The deterioration
the ASTM website.
Available from the Superintendent of Documents, U. S. Government Printing
Office, Washington, DC 20402. See also Practice D3698.
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D4579–00 (2006)
may be due to damage, corrosion or accumulation of contami- when the solvent is pumped out of the machine. (The water
nants on the heating surface. solution floats on top of the solvent.) Pump the acid solvent
6.3.2 Exposed Heating Surfaces—Exposure of gas and into steel drums containing about one pound of soda ash. Care
electric heating surfaces to the air can cause solvent decom- should be taken to remove all solvent from water separators,
position. Heating elements exposure is caused by a low solvent pumps etc. Do not insert the bungs in the drums until
level that is not detected by low liquid level controls. neutralization reaction is complete. (Carbon dioxide is formed
6.4 Excessive Amounts of Water—Hydrolysis of certain by the neutralization reaction. If sealed, pressure from the
solvents and impurities can be a factor in the formation of an evolution of carbon dioxide could rupture the drums.)
acid condition. Free water can also remove stabilizer.
8.2 After the solvent has been removed from the degreaser,
6.5 Chlorinated and Sulfonated Oils—Some chlorinated inspect the surface of the water solution in the degreaser. If a
and sulfonated oils used in deep drawing processes begin to
boiling action is observed, break up any lumps that may exist
break down at 150°F (65°C), liberating acidic components. on the bottom of the degreaser using a metal rod or similar
When in contact with boiling solvents such as trichloroethyl-
device. Boiling action is most likely to occur in the boiling
ene, and perchloroethylene that have boiling points above
...