ASTM D3698-99
(Practice)Standard Practice for Solvent Vapor Degreasing Operations
Standard Practice for Solvent Vapor Degreasing Operations
SCOPE
1.1 This standard sets forth recommended work practices for vapor degreasing operations utilizing any of the following halogenated solvents: methylene chloride (dichloromethane), methyl chloroform (1,1,1-trichloroethane), perchloroethylene (tetrachloroethylene), trichloroethylene, and trichlorotrifluoroethane.
1.2 The values given in inch-pound units are to be regarded as the standard. The values stated in parentheses are for information only.
1.3 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation:D3698–99
Standard Practice for
Solvent Vapor Degreasing Operations
This standard is issued under the fixed designation D 3698; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 2.3 Other Documents:
Threshold Limit Values for Chemical Substances and Physi-
1.1 This practice recommends work practices for conven-
cal Agents, ACGIH Industrial Ventilation, ACGIH
tional vapor degreasing operations utilizing any solvent or
NFPA 704 Identification System for Fire Hazards of Mate-
solvent blend that has been categorized as nonflammable.
rials, National Fire Protection Association
1.2 This practice is not intended for use in vapor degreasing
operations utilizing flammable (low flash point) solvents or in
3. Terminology
vapor degreasing operations utilizing enclosed (sealed, air-
3.1 Definitions of Terms Specific to This Standard:
tight) equipment. For these non-applicable operations, users
3.1.1 emergency—any occurrence that may result in an
should consult the solvent or equipment supplier for additional
immediatehazardtohealthincludingexposuresresultingfrom,
information.
but not limited to, equipment failure, rupture of containers, or
1.3 The values given in inch-pound units are to be regarded
failure to control equipment.
as the standard. The values stated in parentheses are for
3.1.2 hazardous operation—any procedure or activity
information only.
where a release of the solvent or the decomposition products of
1.4 This standard does not purport to address all of the
the solvents might be expected to result in a hazard to health.
safety concerns, if any, associated with its use. It is the
3.1.3 nonflammable solvent(s)—as used herein, is a solvent
responsibility of the user of this standard to establish appro-
or solvent mixture having a NFPA flammability hazard rating
priate safety and health practices and determine the applica-
of 1 or lower (as determined by NFPA 704), intended for use
bility of regulatory limitations prior to use.
in vapor degreasing operations.
2. Referenced Documents 3.1.4 solvent vapor degreaser—a solvent and corrosion-
resistant tank with a heated solvent reservoir or sump at the
2.1 ASTM Standards:
bottom, a condensing means near the top, and freeboard above
D 2110 Test Method for pH of Water Extractions of Halo-
the condensing means, in which sufficient heat is introduced to
genated Organic Solvents and Their Admixtures
boilthesolventandgeneratehotsolventvapor.Becausethehot
D 2942 Test Method for Total Acid Acceptance of Haloge-
vapor is heavier than air, it displaces the air and fills the tank
nated Organic Solvents (Nonreflux Methods)
2 up to the condensing zone. The hot vapor condenses on the
D 4276 Practice for Confined Area Entry
cooled condensing means, thus maintaining a fixed vapor level
D 4579 Practice for Handling an Acid Degreaser or Still
2 and creating a thermal balance.
D 4757 Practice for Placarding Solvent Vapor Degreasers
3.1.5 solvent vapor degreasing operations—the process by
2.2 Government Documents:
which materials are immersed in vapors of boiling liquids for
40 CFR Part 63.460-469 U.S. EPA, National Emission
the purpose of cleaning or altering their surfaces, and are
Standards for Halogenated Solvent Cleaning
subsequently removed from the vapors, drained and dried in a
29 CFR Part 1910.146 U.S. Department of Labor, Occupa-
solvent vapor degreaser.
tional Safety and Health Standards, Permit-Required Con-
fined Spaces
4. Significance and Use
4.1 This practice is intended for use by employers in
1 developing their own specific operation standards for solvent
This practice is under the jurisdiction of ASTM Committee D-26 on Haloge-
nated Organic Solvents and Fire Extinguishing Agents and is the direct responsi- vapor degreasing operations.
bility of Subcommittee D26.02 on Vapor Degreasing.
Current edition approved June 10, 1999. Published August 1999. Originally
published as D 3698 – 79. Last previous edition D 3698 – 92. Available from American Conference of Governmental Industrial Hygienists,
Annual Book of ASTM Standards, Vol 15.05. Inc., 1330 Kemper Meadow Dr., Suite 600, Cincinnati, OH 45240.
3 5
Code of Federal Regulations, available from U.S. Government Printing Office, Available from National Fire Protection Association, 1 Batterymarch Park,
Washington, DC 20402. Quincy, MA 02269–9101.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D3698
4.2 Certain vapor degreasing operations are subject to the exhaust is used on the flue, a back draft diverter shall be used.
requirements of the National Emission Standards for Haloge- Gas burners shall be provided with safety protection to provide
nated Solvent Cleaning (Halogenated Solvent Cleaner NES- shut down if the pilot or igniter fails.
HAP) as found in 40 CFR Part 63, Subpart T. The determina-
6.2.4 Heating elements shall be so designed and maintained
tion of the applicability of these, or any additional
that their surface temperature will not cause the solvent or
requirements is the responsibility of the user.
mixture to decompose or break down.
4.3 This practice is not intended to address all of the
6.2.5 New solvent vapor degreasers or solvent stills of more
requirements contained in the Halogenated Solvent Cleaner
than 4 ft of vapor area shall be equipped with suitable
NESHAP. Development and implementation of training pro-
clean-out or sludge doors located at the bottom of the boiling
grams, recordkeeping, and other additional requirements of the
sump and any other sump having an area of more than 4 ft
NESHAP are the responsibility of the user.
(0.37 m ). These doors shall be designed and gasketed so that
there will be no leakage when they are closed.
5. Exposure Limit
6.2.6 Floors and platforms around degreasers shall be pre-
5.1 No employee may be exposed to any of the solvents
vented from becoming slippery both by the original type of
utilized in vapor degreasing operations covered by this section
construction and by frequent cleaning. They shall be firm,
in excess of either the OSHA Permissible Exposure Limits
sound, and of the design and construction to minimize the
(PEL), the ACGIH Threshold Limit Value (TLVt), or any
possibility of tripping. Railing requirements for platforms
manufacturer’s recommended exposure limit.
appear in 29 CFR § 1910.23(c).
6.2.7 When an open top degreaser is located in a pit below
6. System Location and Design
floor level, the elevation of the top of the degreaser shall be a
6.1 Location:
minimum of 42 in. (1066 mm) above the floor level or the
6.1.1 Degreasers shall be placed in a room having ventila-
operating level or else a 42-in. (1066-mm) railing must be
tion adequate to maintain operator exposure below the appro-
provided in accordance with 29 CFR § 1910.23(c)(3) and
priate exposure limit.
(e)(1). Pit ventilation shall be designed to provide a minimum
6.1.2 A degreaser shall be installed so that it is not affected
oftwoairchangesperminutewheneveradegreaserisinstalled
by drafts from sources such as windows, doors, fans, unit
in a pit more than 18 in. (457 mm) deep.
heaters, ventilators, or adjacent spray booths. Normal air
6.2.8 Degreasers shall be equipped with means to prevent
circulation (at velocities not exceeding 50 ft (15.24 m)/min) is
solvent vapors from overflowing, such as a vapor level control
recommended and should not be confused with direct drafts
device (vapor safety thermostat) sensitive enough to shut off
such as those listed in the preceding sentence. Drafts should be
the heat input if the solvent vapor level rises above the primary
diverted from the top of the degreaser by the use of baffles
condensing coils.
located on the windward side of the degreaser.
6.2.8.1 The vapor safety thermostat is typically set at a
6.1.3 No degreaser shall be installed in areas where solvent
temperature 20 to 30 % below the boiling point of the solvent
vapors may reach open flames or high-temperature surfaces
(based on the boiling point in °F) except for very low boiling
above 350°F (176°C). Solvent degreasing equipment shall not
solvents (for example, methylene chloride). For these solvents,
be installed in the proximity of welding and heat treating
the vapor safety thermostat should be set at ambient tempera-
operations or space heaters unless adequate ventilation of the
ture +10°F, but never higher than 100°F (38°C). Recom-
degreaserorothermeansareprovidedtopreventsolventfumes
mended temperatures for vapor safety thermostat settings can
from contacting the high-temperature source.
be determined fromAppendix X1, or from the solvent supplier.
6.1.4 Gas-heated degreasers (provided with natural draft
6.2.9 Degreasers shall be equipped with safety devices in
ventilation of combustion tube) shall not be located in an area
the boiling sump that can shut off the heat input if the solvent
where the general mechanical exhaust system produces nega-
level drops too close to the heating coils (sump level control
tive pressure, unless positive exhausting of combustion prod-
device) or if the solvent becomes too contaminated (sump
ucts by mechanical means is provided.
safety thermostat).
6.2 Design:
6.2.9.1 A sump level control device is designed to prevent
6.2.1 The level of vapors below the top edge of the
heat input unless there is adequate solvent in the boiling sump.
degreaser (freeboard) shall at a minimum be a 1.0 ratio of
Such devices may be mechanical (liquid level sensor) or
height to width.
thermostatic (liquid level safety thermostat). The liquid level
6.2.2 All degreasers shall have durable covers which shall
sensor should interrupt heat input if the liquid level is less than
be secured in a closed position when degreasing operations are
2 in. above the heating coils. Liquid level safety thermostats,
not occurring. Sliding covers, which allow partial closure
usedonelectricallyheateddegreasers,areattachedtotheupper
during degreasing operations are preferred.
surface of the heating coil with a maximum recommended
6.2.3 Where gas is used as a fuel for heating, the combus-
setting of 20°F above the boiling point of the solvent.
tion chamber of the degreaser shall be of tight construction,
except for such openings as the exhaust flue, and those that are 6.2.9.2 Degreasers should also be equipped with a sump
necessary for supplying air for combustion. Flues shall be of safety thermostat immersed in the boiling liquid. If the de-
corrosion-resistant construction and shall extend to the outside greaser is equipped with an auxiliary still, then the degreaser
air. If mechanical exhaust is used on the flue, there shall be sump safety thermostat should be set at the temperature
provision for outside fresh make-up air. If nonmechanical corresponding to 25 % oil contamination (see 7.4.2.1). The
D3698
sump safety thermostat in the auxiliary still should then be set free of leaks and the water separator is functioning properly to
at the temperature corresponding to 25 % oil concentration if prevent contamination in the degreaser.
the unit is electrically heated. However, the sump safety
7.2 Degreasing—In degreasing follow the procedures enu-
thermostat in the auxiliary still can be set at the temperature merated:
corresponding to approximately 70 % oil concentration if the
7.2.1 Do not allow work loads to exceed designed degreaser
unit is indirectly heated by such means as steam. Recom-
capacity.Work should not generally occupy more than 50 % of
mended temperatures for the sump safety thermostat can be
the open horizontal area of the machine unless the work
determined from Appendix X1, or from the solvent supplier. permits easy passage of vapor through or around it. Secure a
6.2.9.3 Ifreclamationofsolventwillbeconductedusingthe
highly durable tag to each degreaser indicating the maximum
degreaser’s boiling sump as the still sump, then the safety weight and volume of a single load expressed in terms of
thermostat in the degreaser may be adjusted to the higher
pounds per load and loads per hour.
setting during that operation and then readjusted to the tem-
7.2.2 Place work loads, where necessary, in free-draining
perature corresponding to 25 % oil concentration during nor-
nonporous baskets, trays, racks, and so forth, and position to
mal operation.
eliminate solvent drag out.
6.2.10 Degreasers shall be equipped with a device to pre-
7.2.3 When working with cup-shaped parts or parts with
vent heat input unless there is adequate cooling to ensure
cavities that may collect liquid, load the parts, and rotate if
sufficient condensation of vapor in the degreaser.
necessary, in a manner to facilitate complete drainage while in
6.2.11 Degreasers of the spray type shall be equipped with
the vapor zone.
a method that will prevent spray pump operation unless the
7.2.4 Do not allow the vertical rate of entry and withdrawal
solvent vapors have reached normal operating levels.
of work loads to exceed the maximum degreaser design, which
6.2.12 Steam-heateddegreasersshallbeequippedwith“pop
should not exceed 11 ft/min (3.4 m/min).
safety valves” down-stream from any pressure control. The
7.2.5 Allow the work loads (and accompanying baskets,
pressure relief setting should be consistent with the solvent in
trays, racks, and so forth) to remain in the vapor zone until
use, and may be determined from Appendix X1, or from the
condensation on the work loads (and accompanying baskets,
solvent supplier.
trays, racks, and so forth) has stopped.
6.2.13 Conveyorized degreasers shall be equipped with a
7.2.6 Conduct all spraying of work loads within the vapor
thermostat that will prevent work from being processed by
zone.
stopping conveyorized operation unless the solvent vapors
7.3 Shutdown—In shutting down, follow the procedures
have reached the normal operating levels.
enumerated as follows:
7.3.1 Stop the throughput of the work loads.
7. Degreaser Operations Procedures
7.3.2 Turn off the heat supply.
7.1 Start-Up—In starting a vapor degreaser follow the
7.3.3 After the level of the vapor has dropped below the
procedures enumerated sequentially where applicable:
condensing coil, turn off the cooling/condensing system.
7.1.1 Turn on the cooling/condensing system coolant and
7.3.4 Turn off the air exhaust equipment, if any.
check to ensure proper operation.
7.3.5 Put covers in place and maintain the degreaser in a
7.1.2 Start air exhaust equipment, if any.
closed condition when the degreaser is not in actual use
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