WASTEWATER MINIMIZATION AND

TREATMENT |

Wastewater generated from aqueous and semi-
aqueous based cleaning processes used in the metal
cleaning industry might require pretreatment prior
“to discharge to the sewer system to meet local,
state, or federal regulations. The amount of
pollutants and the quantity of wastewater
generated depend on the cleaning process. The
type of treatment technology used depends solely
on the quality and quantity of the wastewater
generated.

‘ Contaminants

The wastewater generated from aqueous and semi-
aqueous based cleaning processes can contain
organic contaminants along with dissolved or
suspended metals. An additional problem
encountered with alkaline cleaners is the high pH
of the wastewater.

Organic Matter

Organic matter in the wastewater results from
removal of oil and grease from the parts being
cleaned and from the chemical constituents of the
cleaners. :

Generally considered a single type of pollutant, oil
and grease are not categorized by any chemical
formula, but rather as a general type of semi-liquid
material that may contain fatty acids, fats, soaps,
and other similar materials. Oily wastewater can
be placed into five categories:

© Free oil: oil which rises rapidly to the surface
under quiescent conditions;

© Mechanical dispersions: fine oil dropiets ranging
. in size from microns to a few millimeters in
diameter which are stabilized by electrical

charges or other forces but not through the
influence of surface active agents; .

Chemically stabilized emulsions: oil droplets
similar to- mechanical dispersions but with
enhanced stability resulting from surface active
agents at the oilAvater interface; .

* "Dissolved" oil: truly soluble chemical species
plus very finely divided oil droplets (typically
less than 5 microns diameter). This form
generally defies removal by normal physical

means,

* Oil-wet solids: oil adhering to the surface of
particulate material in the wastewater.

Organic matter such as oil and grease contribute to
visual and olfactory problems, interfere with
normal oxygen transfer from air to water, and exert
both a biological oxygen demand (BOD) and a
chemical oxygen demand (COD). The measure of
organic matter in a waste stream is generally
characterized by measuring the BOD and COD.
BOD is a measure of the oxygen consuming
characteristic of organic matter. COD measures
oxygen consuming pollutants in wastewater. COD
measures the total oxidizable carbon in the
wastewater and relates to the chemically bound
oxygen in the water. BOD relates to the dissolved

oxygen.

Most aqueous and semi-aqueous chemicals used in
cleaner formulations are biodegradable. The term
"biodegradable" may be misleading, because it may
take too long for these chemicals to break down
into their constituent elements to be considered
“environmentally acceptable."



wy

1g

ALTERNATIVE METHOD OVERVIEW

In developing and selecting an alternative
technology for metal cleaning, several criteria
should. be considered. These considerations
include: : :

Organizational

Technical
Economic

Environmental, Heaith, and Safety

Organizational
Important considerations include:

* Compatibility with other corporate goals.
Corporate policy might disallow the use: of
particular solvents because of their impact on
product quality.

° Feasibility given existing organizational structure.
Environmental concerns. may already be the
responsibility of a particular task force within
the company. Some companies have made
environmental performance a criterion for

* evaluating managerial performance.

* Compasibility with corporate environmental policy.
Some alternatives generate other forms of
emissions, effluents, or wastes that are also the
subject of corporate environmental goals.

Technical

The technical feasibility of the alternative process
must be evaluated on a case-by-case basis. The
first step is to develop criteria for evaluating the
alternative process taking into account applicable
federal, state. and local regulations that might
apply. As discussed in the Foreword Section, the
Clean Air Act Amendments of 1990 have several
provisions pertaining to stratospheric ozone
Protection that must be considered before selecting
alternatives. These include Section 608: National
Emissions Reduction Program. Section 611: -
Labeling. and Section 612: Safe Alternatives
Policy.

Important technical considerations in-
clude:

Chemical cleaning ability

Physical and chemical characteristics
of cleaning process

Compliance to specifications
Material compatibility

Effect on subsequent processes
Process control

Production rate requirements
Ease of new process installation
Floor space requirements

Operating and maintenance require-
ments.





62



for full-scale implementation in early 1990.
Development of the ceramic membrane
ultrafiltration technology operating parameters was
completed in 1990. One product was identified as
being completely recyclable at operating
temperatures and concentration. Process emissions
would be limited to an oily emulsion and solution
from the membrane cleaning procedure.

Full-scale implementation is scheduled for 1992-95
and will include an ultrafiltration system to
facilitate the recycling of heavily soiled solutions.

Overall, the project has achieved a number of its’
objectives: ‘

« Identified several commercially available water-
based cleaners as effective substitutes for
halogenated solvent degreasing; :

© Identified alternative cleaners and cleaning
methods for heavy asphaltic and paraffinic soils
not cleaned in aqueous immersion cleaners;

i

« Established a data base to tailor optimum
operating conditions for particular degreasing
requirements;

« Concluded that efficient cleaning systems can be
designed for all parts configurations, including
long narrow tubes, using a variety of off-the-
shelf equipment; and

« Demonstrated” that using a specific
ultrafiltration technology cleaning solutions can
be recycled at Operating concentrations and
temperatures. :



STRUCTURE OF THE MANUAL

This manual is divided into the following sections:

INTRODUCTION TO METAL CLEANING

This section provides a brief description of metal cleaning.

EXISTING CLEANING PROCESS CHARACTERIZATION

This section describes the tools to characterize meta! cleaning operation.. It is
important to understand the reiationship between metal cleaning and the other
aspects of manufacturing processes and how CFC-113 and/or MCF are used.

ALTERNATIVE METHOD OVERVIEW

This section highlights the criteria for developing and selecting a non-CFC/MCF
strategy for metal cleaning. Various technical and managerial considerations are
discussed.

ALTERNATIVE MATERIALS AND PROCESSES

This section describes the Operational principles and outlines the advantages and
disadvantages of each technology.

WASTEWATER MINIMIZATION AND TREATMENT

This section presents methods to minimizé and treat wastewater from aqueous
and semi-aqueous cleaning processes.

CASE STUDIES OF INDUSTRIAL PRACTICES

This section describes case studies that illustrate the successful implementation of
alternative technologies,



68

Cleaner Regeneration

All the cleaners selected for evaluation have some
degree of soil rejection capability. Soil rejection
capability is accomplished by the surfactant
Package included in the cleaner. The surfactant
package reduces surface tension for effective
contact by the cleaner’s active ingredients, but then
does not allow the removed hydrocarbon soils to
be emulsified in the cleaner. As a consequence,
oils and greases float on the top of a quiescent
emulsion cleaner tank. The soil rejection
capability provides an opportunity to regenerate
the cleaner, greatly extending operating life and
reducing the volume of hazardous waste
generation. Rejected hydrocarbon soils can be
Temoved from an operating aqueous cicaner in
several ways: skimming off the oil. absorption
using floating absorption blankets or pillows. using
a coalescer, and through ultrafiltration. .



26



3B

leaching and absorption of sonic energy. [t is also
important to optimize the size of the load to the
size of the tank. Both ultrasonic and spray
equipment can..be used to’ great advantage,
especially in rinsing. There are benefits for both
immersion ultrasonics and spray using high-purity
water. Low pressure (40-80 psi) at relatively high
volumes is good for initial rinsing. It is critical to
keep the part wet at all times prior to final drying.
The spray design should be able to reach all part
surfaces by mechanically manipulating the part or
the spray nozzles. A secondary immersion-
ultrasonic rinse is especially useful for parts with
complex geometry or holes.

In some instances final rinsing with DI water or an
alcohol, such as isopropanol, can remove residues
and prevent water spots.

Other Process Considerations

Product design can have a significant influence on
cleanability. The choice of materials and part
configuration should be reviewed for opportunities
to make changes that have a major influence on
the success of water-based cleaning.

Care should be taken to prevent cleaning fluids
from being trapped in holes and capillary spaces.
Low surface tension cleaners sometimes penetrate
spaces and are not easily displaced by a higher
surface tension, pure water rinse. Penetration into
small spaces is a function of both surface tension
and capillary forces.

Water-based cleaning is sometimes not as forgiving
as CFC-113 and MCF cleaning. Good engineering
and process control are more critical in preventing
problems. Useful parameters for process control
include bath temperatures, pH, agitation, rinse
water quality, and cleaning bath quality. Part
inspection by a method such as contact angie,
turbidity, or ASTM F24 can be very useful
Valuable bath and water quality measurements
could include conductivity/resistivity, particle
count, turbidity, and TOC (total organic carbon).

Drying presents the major challenge when
switching to aqueous cleaning. For simple parts,
this obstacle may be minimal. but for complex
. parts drying may require considerable engineering

and experimentation. Solvent equipment that is
currently in use has no real provision for drying:
the thermodynamics of CFC-113 and MCF are
favorable to spontaneous evaporation.

Aqueous cleaning requires careful consideration of
drying materials. Evaporative removal: of bulk
water is usually not practical from the perspective
of energy use or process time. Compact turbine
blowers with filtered ourputs can mechanically
remove 90 percent or more of the water. Design
options in blowers include variation of pressure,
velocity, and volume flow. Other sources of air
include declicated compressors or plant air; great
care must be taken to assure desired air quality by
appropriate filtration of oil, particles, and
moisture. When using such options, economics

y and noise reduction are other considerations.

Humidity and air conditioning control, and the
associated economics. may be an issue for the
equipment and the plant.

Evaporative drying following mechanical water
Temoval can be accomplished using infrared
heating, clean dry air-heated or at ambient
temperature, or vacuum heated drying. Dryers can
be designed. for either in-line or batch operations.
Drying design should always be confirmed by
experimentation.

Wastewater treatment and recycling is an
important consideration. Some detergents and
surfactants are biodegradable, while others are not.
In many applications the cleaning bath is changed
infrequently and a relatively low volume of
wastewater is discharged. In others, the water can
be evaporated to leave only a small volume of
concentrated waste for recycling.

Recycling or regeneration of the cleaner/detergent
solution is feasible and should be considered. This
can be accomplished using a combination of oil
skimming techniques, coalescing separators, and
ultrafiltration (ceramic membranes).

Details on wastewater treatment and recycling are ©
presented later in this manual.



58

solution, regenerating the sodium form so that it
is ready for another cycle of operation. The
Tegeneration reaction is reversible: the ion
exchanger is not permanently changed.

Conceptual Design of a
Wastewater Treatment
System

In most aqueous and semi-aqueous cleaning
systems the wash and rinse water is recycled and
Teused for a certain period of time before being
discarded. Because of stringent environmental
Tegulations, high water costs, and high energy
costs, recycling of wastewater is recommended.
Exhibit 17 represents a conceptual design of a
semi-continuous wastewater treatment system that
treats wastewater generated ‘from the metal
cleaning industry.

‘The system consists of six unit operations. Unit.1
is a holding tank where the wastewater generated
is periodically discharged. Unit 2 is an enhanced
gravity separator that removes free floating oil and
suspended solids. Unit 3 is a ultrafiltration device
that removes the emulsified-dissolved oils. Unit 4
is an ion-exchange column used to remove
dissolved metals. Unit 5 is an activated carbon bed
used to remove organic matter. Unit 6 is a pH
adjusting tank. The final wastewater discharged
from this system can be either reused as process
water for an aqueous or semi-aqueous cleaning
Process or discharged to the Public Owned
Treatment Works (POTWs). .

Contract Hauling of
Wastewater

For small users of aqueous and semi-aqueous -

Cleaning processes it might be more economical to
contract waste treatment rather than treating it in-
house. In some cases, the volume of wastewater
can be reduced to make it more economical for
shipment (hauling) by evaporating: excess water.
Most companies that contract haul the waste

generally treat it in large treatment facilities such -

as large wastewater treatment plants or large
incinerators where it is burned as fuel. Waste

from semi-aqueous processes is a fuel source for
incinerators. :



AQUEOUS CLEANING

. ADVANTAGES

Aqueous cleaning has several advantages over organic
solvent cleaning. :

Safety - Aqueous systems have few problems with
worker safety compared to many soivents. They are
not flammabie of explosive. Consult matenal safety
data sheets for information on health and safety.

«Cleaning ~ Aqueous systems can be designed 10
clean particies and films better than sorvents.

+ Multiple Degrees-of-Freedom -- Aqueous svstems
have mutuple degrees-ot-freedom in process. aesign.
formutation and concentration. This freedom heips
aqueous cleaning pronde supenor cleaning for a
wider vanery of contamination. ‘

* Removal of inorganic or Polar Soils — Aqueous
cleaning is paruicularty good for cleaning inorganic
or polar matenals, Many machine shops are using
of converting to water-based jubricants and coolants,
versus oil-based for environmental and other
reasons. These are ideally sued to aqueous

Cleaning processes.

* Oil and Grease Removal — Organic films. oils, and
greases can be effectively removed by aqueous
chemistry. :

* Multiple Cleaning Mechanism — Aqueous cleaning
functions by several mechanisms rather than just
solvency. These inciude saponification (chemical
Feacuon), displacement. emulsification. dispersion.
and others. Particies are effectively removed by
surface activity coupled with the application of
energy. :

© Ultrasonics Applicability — Ultrasonics are much’
more effective in water-based solvents than in CFC-
113 of MCF sotvents.

i
© Chemical Cost - Aqueous cleaning solutions are
generally fess expensive than solvents.

Exhibit 6

DISADVANTAGES

Depending upon the specific cleaning application there are
also disadvantages. .

© Cleaning Difficulty — Parts with blind holes and small
crevices may be difficult to clean, and will require process.
Optumizatioa.

* Process Control ~ Solvent cleaning is a very forgiving
Process. To be effective. aqueous processes require
caretul enginecnng and control.

+ Rinsing ~ Some aqueous cieaner residues can be difficult
tonnse, Some surtactants are especiaity difficult to rinse.
Trace residucs may be detnmental for some applications
and matenals. Special caution should be taken for parts
requiring surequent vacuum deposition. liquid oxygen
contact, etc. Iinsing can be improved using DI water or
alcohol nnse.

. Drying - It may be difficult to dry cenain part
geomeines with crevices and blind holes. A piece of
drying equipment is often required. :

+ Floor Space ~ In some instances aqueous cleaning
equipment may require more floor space.

+ Material Companbility ~ Corrosion of metals of delayed
environmental stress cracking of certain polymers may
occur. -

‘+ Water — In some applications high purity water is needed.
Depenaing on punty-and volume high punty water can be
expensive.

«Energy Consumption ~ Energy consumption may be
higher than solvent cleaning in applications that require
heated rinse and drying stages.

© Wastewater Disposal — In some instances use of aqueous
cleaning may require wastewater treatment prior to
discharge.



ot

SUMMARY AND REVIEW

The discussions presented in this manual have described a step-by-step approach to
eliminating CFC-113 and methyl chloroform in solvent cleaning processes. The steps
include: :

Determine where and why CFC-113 and methyl chloroform is used in cleaning
operations:

Characterize existing cleaning processes:

Establish criteria for selecting alternative cleaning processes;

Review alternatives that could be used to replace solvent cleaning and determine
which alternative best suits the cleaning needs:.

Consider options for wastewater minimization and treatment.

The next section presents some case studies that provide examples of successful programs
on alternatives being implemented in industry. The case studies are followed by references
and list of vendors that may be an additional source of.information.



39

* Controlled exhaust from refrigeration unit to
prevent excessive heat from reaching the
separator chambers. :

Material compatibility is another important
consideration. The HCFC-123/HCFC-141b blends
require compatibility testing with magnesium, zinc
and other metals. In addition, the solvent blends
have shown some adverse effects with plastics such
as ABS, acrylic, and Hi-Impact Styrene. Like
metals, plastics need to be tested on an individual
basis.



81

* Miscellaneous parts. pipe fittings, etc;

¢ 5 drums (each 55 gallons) initial fill for the
semi-aqueous process; and sg!

« Labor.

LA-Z-BOY estimates that the operating costs of
the semi-aqueous based process is about half that
of the methyl chloroform based process. This is
based of the fact that one drum of Bio T is used
per month. At a cost of $16.5 per gallon. this
results in monthly costs of $907.5. The monthly
cost of the solvent process was estimated at $1.836.
This includes cost of virgin solvent & costs of
disposal of waste solvent. The cost calculations for
the solvent and semi-aqueous process do not
include energy costs of operating the vapor
degreaser and the recirculating pumps respectively.
However, it is believed that the aqueous process
energy costs are not higher than the solvent
Process energy costs. -



Exhibit 2

CORPORATE POLICIES ON CFC-113 REDUCTION SCHEDULE

‘Reduction Schedule
Company . CFC-113

American Electronics Association Member Phaseout 2000
Companies. U.S.

AT&T, U.S. Phaseout 1994
Canon. Japan . Phaseout 1994
Digital Equipment Corporation. U.S. Phaseout 1995
Hitachi Corporation. Japan Phaseout 1993 _
Honeywell. U.S. : Phaseout 1997
TBM, U.S. Phaseout 1993
Intel Corporation. U.S. Phaseout 1992
Matsushita, Japan Phascout 1995
Motorola, Inc., U.S. Phascout 1992
Nissan Motor Corp., Japan ’ Phascout 1993
Northern Telecom. Canada Phascout 1991
Seiko-Epson. Japan Phaseout 1993
Sharp Corporation, Japan . Phaseout 1995
Texas Instruments, U.S. Phascout 1994
Toshiba Corporation, Japan Phaseout 1995
Phascout 1994



Disclaimer

The U.S. Environmental Protection Agency (EPA). the Industry Cooperative for Ozone Layer
Protection (ICOLP), the ICOLP committee members. and the companics that employ the
ICOLP committee members do not endorse the cleaning performance. worker safety, or
environmental acceptability of any of the technical opuons discussed. Every cleaning
operation requires consideration of worker satety and proper disposal of contaminants and
waste products generated from cleaning processes. Morcover, as work continues, including
additional toxicity testing and cvaluation under Section 612 (Safe Alternatives Policy) of the
Clean Air Act Amendments of 1990 and elsewhere. morc information on the heaith,
environmental and safety effects of alternatives will become available for use in selecting
among alternatives discussed in this document.

EPA and ICOLP. in furnishing or distributing this information, do not make any warranty
or representation. either express or implied. with respect to its accuracy, completeness or
utility, nor does EPA and ICOLP assume any liability of any kind whatsoever resulting from
the use of. or reliance upon. any information. material. or procedure contained herein,
including but not limited to any claims regarding health. safctv, cnvironmental effects or fate,
efficacy, or performance, made by the source of the information.

Mention of any company or product in this document is for informational Purposes only, and
does not constitute a recommendation of any such company or product. cither express or
implied by EPA. ICOLP, ICOLP committee members. and the companics that employ the
ICOLP committee members.



36

In cases where extreme cleanliness is required, the
hydrocarbon/surfactant cleaning can be followed by
a fully aqueous wash step with an alkaline
detergent and a deionized water rinse. As in
aqueous cleaning, it is important to note that both
the wash and the rinse stage are Tecirculating;
these solutions are not continuously discharged.

In the wash step, the hydrocarbonéurfactant
cleaner is applied to the part being cleaned with
some form of mechanical energy. . Low flash point
hydrocarbon/surfactant cleaners are generally not
heated; however, some are slightly warmed when
the cleaner is used in a diluted form. High flash
Point hydrocarbon4urfactant cleaners May be
heated to within 20-30°F of their flash point to
temove difficult soils. Cleaners that are ignitable
should not be used in vapor or Spray cleaning
without an inert atmosphere or other protective
equipment. Application methods that avoid
misting such as spray-under immersion. spin-under
immersion, or ultrasonics should be used. Dilute
hydrocarbon emulsion cleaners formulated with
water may be heated. Less mechanical energy is
needed when using a hydrocarbon/surfactant
solution than when using an aqueous solution
because of the high solvency of hydrocarbon/
Surfactant cleaners,‘

A rinse with clean water removes the residues left
by the wash step. The rinsé step is necessary when
concentrated hydrocarbon/ surfactant cleaners are
used because of their low volatility (which prevent
them from evaporating from the parts cleaned in
the wash stage). The rinse step may not be
necessary when a dilute hydrocarbon/surfactant
emulsion is used, if the level of cleanliness needed
does not require removal of the residue from the
Wash stage. In some instances, alcohol is used as
a final rinse step. The rinse step may also serve as
a finishing process and in some instances is used to
apply rust inhibitors to the parts.

The drying step serves the same function as it does
in aqueous cleaning. The removal of remaining
water from the part prepares it for further
processing or prevents it from rusting. Heated or
high velocity room temperature air are the
principal drying agents. As in aqueous cleaning,
the drying step may not be needed if the parts are
Tust inhibited, are not immediately needed, and/or
are moved immediately to another wet process,

The wastewater disposal step is always an
important part of the cleaning process. As in
aqueous cleaning most of the contaminants in the
wastewater are removed by decanters and filters as
the solution is recirculated in the tank.

Some available hydrocarbon/surfactantcleanerscan
be easily separated from the rinse water. This
allows the rinse water to be recycled or reused.
The waste hydrocarbonssurfactant can then be
burned as fucl.' In such cases, contaminants, like
oil and grease, removed from the part being.
cleaned are retained in the hydrocarbon/surfactant
phase, thereby greatly reducing the contamination
loading in the water effluent.

Process Equipment

Equipment for use specifically with concentrated
hydrocarbon/surfactants is available. As with -
aqueous cicaning, this equipment can be classified
as immersion or spray equipment, either batch or
in-line equipment.

Immersion equipment is the simplest design used
in hydrocarbon4urfactant-based Cleaning. The
immersion equipment works with but is not limited
to the dilute emulsion solutions which do not
Present the combustion (flammability) danger of
the concentrated hydrocarbon/ surfactants. These
pieces of equipment may operate in batch or in-
line configuration. Certain solvent vapor
degreasers can be retrofitted to allow immersing of
the parts into the bath of emulsion cleaner. The
parts are simply dipped into the bath which may or :-
may not be heated. Because of the solvency of the
hydrocarbon/ surfactants, little mechanical energy.
needs to be added to achieve adequate cleaniiness.
Higher cleanliness can be achieved by adding
agitation to the process, either mechanically or
with ultrasonics, or by heating the Cleaning
solution.

As with aqueous cleaning, a mechanical Spray
improves the cleaning performance of the solution.
When using concentrated hydrocarbon/ surfactants,

the atomized solution is prone to combustion and

Special care must be taken to prevent it. Nitrogen

blanketing displaces oxygen from the spray

chamber which is enclosed to prevent sparks from

entering.



67

Hydrogen Embrittlement of High
Strength Steel

Testing was conducted in accordance with ASTM
F519, using both cadmium plated and unpiated
Type 1A steel specimens. In this test, the
specimens are subjected to 45 percent of their
ultimate tensile strength while immersed in the test
cleaner. The specimens must not break for a
minimum of 150 hours. The terpene-based
emulsion cleaners passed all tests. The alkaline-
based cleaners passed the test with bare steel but
failed with cadmium-plated steel due to caustic
driven cadmium reembrittlement of the steel test

specimen. f

Effects on Subsequent
Processes ;

Substituting the aqueous cleaning process for
vapor degreasing must not adversely affect the
chemical processes that follow. What was
unknown was whether any residue from the
aqueous cleaners would affect subsequent
processes. The most straightforward method to
look for adverse effects was judged to be the
quality of subsequent finishes. The following tests
were conducted by using the candidate aqueous
cleaners prior to finishing aluminum. followed by
standard quality control tests in accordance with
specification requirements: :

© Chromate conversion coating -- 168-hour salt
spray;

© Chromic acid anodizing -- 336-hour salt spray; ;

* Chromate conversion coating followed by epoxy
primer -- wet and dry adhesion tests, impact
resistance, 3,000-hour scribe line corrosion test,
and 30-day acidified salt spray coupled with
CRES;

© Chromic acid anodizing followed by epoxy primer -
wet and dry adhesion tests, impact resistance,
3,000-hour scribe line corrosion test, and 30-day
acidified salt spray coupled with CRES;

© Chromate. conversion coating followed by epoxy
primer and epoxy enamel -- wet and dry adhesion

.

tests, impact resistance, 3,000-hour scribe line
corrosion test, and 30-day acidified salt spray
coupled with CRES;

* Chromic acid anodizing followed by epoxy primer
and epoxy enamel -- wet and dry adhesion tests,
impact resistance,  3,000-hour scribe line
corrosion test, 30-day acidified salt spray
coupled with CRES;

¢ Phosphoric acid anodizing followed by adhesive
bonding -- crack extension test;

© Phosphoric acid anodizing followed by epoxy primer
-- wet and dry adhesion tests and 3,000-hour
scribe linc corrosion test.

The following tests were conducted by using the
candidate aqucous cicaners prior to finishing steel,
followed by standard quality control tests for
specification requirements: -

¢ Stainless steel passivation -- salt spray verification
test,

¢ Cadmium plating -- adhesion;
« Chromium plating -- adhesion;
* Cadmium-titanium alloy plating -- adhesion.

None of the tests for subsequent effects have
indicated a failure due to the use of the aqueous
cleaners.

Toxicological and Industrial
Hygiene Analysis

Candidate clcaners were initially selected to be low
toxicity matcrials. based on supplier information.
However, Boeing requires that all new materials be
evaluated prior to their use. These evaluations are
still in progress for several of the effective cleaner
candidates. Evaluations of d-limonene and the
glycol ethers have been completed and will be
made available to other organizations on request.



76

Information on. the toxicity of selected
biodegradable solvents was obtained from the
manufacturers and entered in a database.

The solvents were tested to determine their
cleaning efficiency. Preliminary tests showed that
process enhancement was needed if aircraft parts
are to pass the “white glove" test. Hence, tests
were conducted using ultrasonic and mixer
agitation at various temperatures. with and without
Tinsing. To test solvent performance, the selected
solvents were loaded with various amounts of
masking wax, carbonized oil/xylene, or hydraulic
fluid, and their cleaning efficiency was measured as
a function of solvent loading.

Biological acclamation tests were started on Exxon
Exxate 1000 loaded with oil/xylene. In the pilot-
scale solids contact clarifier at Tinker AFB. the
metal sludge floated to the surface. Subsequent jar
tests showed that all of the selected solvents either
float or disperse the sludge. However, flotation of
the metal sludge can be prevented by adding
aluminum sulfate, ferric ion, or magnesium ion.
Additionally, magnesium ion addition caused the
plant to be more susceptible to upsets from
influent changes, and as a result, is not
tecommended. A product, Fremont 776, was
added to the program during Phase III. The
product passed all the screening tests that the
others had, and did not float or disperse the
sludge. Extended corrosion testing indicated that
general corrosion occurred in some cases with
enhancement techniques, especially with the
aqueous solvents. In all cases, no hydrogen
embrittlement occurred.

An ASTM guideline is being developed for
determining biodegradability. The guideline is
based on the Phase I screening procedure and an
eight-day protocol that was completed. Protocol
testing began by examining the selection of phenol
as a test control compound. Also, tests. were
conducted to define the percentage of error
associated with chemical oxygen demand (COD)
measurements. The relative error increases as the
lower limit of detection is approached and
decreases at higher COD analyses. The error
appears to be linear. Repeatability tests were also
conducted, and COD and adenosine triphosphate
(ATP) averages-were plotted. The data from the
TIC/TOC (total inorganic/otal organic carbon)
analyses had less variability than the data from

COD and TOC analyses. A set of guidelines is
being developed by the Air Force and will be
submitted for review to the ASTM task group on
biological effects and environmental fate. An
ASTM set of guidelines will be developed by the
ASTM task group on Biological Effects and
Environmental Fate. The set of guidelines will
include the screening test, the eight-day test
protocol and the 21 day test as steps in a series of
logical events that industry can use in determining
the biodegradability of solvents for use in
individual waste treatment plants. °

The solvents to be used in the full-scale
Phase III tests were selected. They
included:

Exxon Exxate 1000;

Bio-Tck # 140 Saf-Solv;

Orange-Sol De-Solv-It;

3-D Supreme; and

Fremont 776.

Phase III - Full Scale Testing

Phase ITI testing included cleaning Air Force
production parts in an intermediate scale 100-
gallon agitated tank in a cabinet spray washer and -
in a full-scale cleaning tank at Tinker AFB.

Results

‘ Each of the solvents tested in the full-scale test

program could be applied in cleaning processes at
Tinker AFB. As expected from earlier testing, the _
solvents differed greatly in their performance

* depending on soil type. Specific recommendations

for solvent use are included below.

3-D Supreme. The cabinet spray washer and full-
scale tests both indicated that 3-D Supreme was an
effective cleaner for Air Force parts. Applied in
an agitated tank, it would provide an acceptable



‘United States Air and EPA/400/1-91/019
Environmental Protection Radiation June 1991
_ Agency (ANR-445)

SEPA Alternatives for CFC-113 —
And Methyl Chloroform in
. _ Metal Cleaning 7

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24

Public information has made plants more
accountable to the concerns of neighboring
communities.

¢ Potential of alternatives for ozone depletion and
global warming. Each alternative must be
evaluated for its contribution to ozone
depletion and global warming. These issues will
be evaluated as part of the overall risk
characterization that will be conducted by EPA
under Section 612 of the Clean Air Act.

« Energy efficiency. AS energy costs rise, it is
important to consider the energy requirements
of each alternative. The use of energy efficient
alternatives is also desirable from a global
warming perspective. Energy issues will be
evaluated as part of the overall risk
characterization under Section 612: Safe
Alternatives Policy of the Clean Air Act.

° Effects on emissions, effluents. and wastes
generated. Determine whether environmental
problems are eliminated or merely transferred
from one medium to another. Each alternative
has differing effects on water. air, and land
pollution. Issues such as these will be evaluated
as part of the overall risk characterization that
EPA will conduct as part of Section 612: Safe
Alternatives Policy of the Clean Air Act.

* VOCconcerns. In many areas, switching solvents
can take you from an existing to a new/modified
source, subject to repermitting and more
stringent controls. Limitations on VOC
emissions may influence your choice of
alternative. In the U.S., for example, certain
States have legislation that restricts the use of
solvents that are VOCs. Some states also ban
the use of substances (e.g., methylene chloride
in New Jersey) because of possible toxic health
effects. Application-specific exemptions and
containment criteria may also exist. so VOC
Tegulatory provisions should be researched
thoroughly. The air toxics provisions of the
1990 Clean Air Act Amendments target 189
toxic air pollutants. Of these, 149 are organic
compounds,

© Toxicity and Worker Safety. Alternatives should.
minimize occupational exposure. The
Occupational Health Safety Administration
(OSHA) has set Personal Exposure Limits

(PELs) for many chemicals and should be
considered before selecting alternatives. In
addition. the American Conference of
Governmental and Industrial Hygienists
Provides threshold limit values (TLVs) for
different chemicals. As part of the

implementation strategy for Section 612 of the .

Clean Air Act Amendments. EPA has also
initiated discussions with NIOSH, OSHA, and
other governmental and nongovernmental
associations to develop a consensus process for
establishing occupational exposure limits for the
most significant substitute chemicals.

Flammability. Fire and expiosion hazards are
very important considerations. In some
instances changes in process will have to be
brought to the attention of insurance carriers.
Flammability will be evaluated as part of the
overail risk characterization that will be
conducted by EPA under Section 612 of the
Clean Air Act. ,



References

Bailey, P.A. 1977. The treatment of waste emulsified oils by ultrafiltration. Filtration and Separation: 53-55.
Bansal, LK. 1975. Ultrafiltration of oily wastes from process industries. AICHE ‘Symposium Series: 93-99.

Baran. Yu,. V., A.M. Ovsyankin, V.V. Ushakov, and G.M. Franchuk. 1986. Cleaning metal surfaces with
electroaerodynamic aerosol jets.

Bhattacharyya, D., A.B. Jumawan, R.B. Grieves, and LR. Harris. 1979. Ultrafiltration characteristics of oil-
detergent-water systems: membrane fouling mechanisms. Separation Science and Technology, 14(6): 529-549.

Chevez, A.A. et al. 1990 (November). Substitution of cleaners with biodegradable solvents, phase I,
extended performance testing. Draft. ESL-TR-93. Air Force Engincering and Services Center, Engincering
and Services Laboratory.

Cohen. LE., and J.A. Hook. 1987 (February). Corrosion of anodized aluminum by alkaline cleaners: causes
and cures. Plating and Surface Finishing: 73-76.

Cohen, LE. 1987 (November). How clean is your ‘CLEAN’ metal surface? Plating and Surface Finishing:
58-61. j

Daufin, G., J.P. Labbe, and J. Pagetti. 1977. Corrosion inhibition of an aluminum-silicon-magnesium alloy
in alkaline media. Corrosion Science 17: 901-912.

Jansen, G., and J. Tervoort. 1984 (November). Longer bath life in alkaline cleaning. Product Finishing: 6-12.
Kaliniichuk, E.M., LA. Makarov, and ILI. Vasilenko, and N.A. Sukhovukhova. 1973. Purification of
petroleum-refinery waste waters by coagulation and regeneration of the coagulant sludge. Consultants Bureau:
756-761.

Lee, S., Y. Aurella. and H. Rogers. 1984, Concentration polarization. membrane fouling and cleaning in
ultrafiltration of soluble oil. Journal of Membrane Science 19: 23-38.

Linford, H.B. and E.B. Saubestre. 1950 (December). Cleaning and preparation of metals for electroplating.
Plating and Surface Finishing: 1265-1269.

Lipp, P., C.H. Lee, and CJ.D. Fell. 1988. A fundamental study of the ultrafiltration of oil-water emulsions.
Journal of Membrane Science 36: 161-177. :

American Society for Metals. 1964. Metals Handbook, Volume 2. pages 317-325.

American Society for Metals. Surface Cleaning Fi inishing and Coatings. in American Metals Handbook, 9th
Edition, Volume 5.

Priest, W. 1978 (March). Treatment of waste oil emulsions by ultrafiltration. Water and Waste Trearmenr: 42-
43.

Schrantz, J. 1990. Rinsing -- a key part of pretreatment. Industrial Finishing: 24-29.

Seislowski, S. 1990 (February). Cleaning basics part 2 - soils. Metal Finishing: 43-46.



78

Bio-Tek # 140 Saf-Solv. The Bio-Tek product was
dropped because full-scale testing showed
inadequate cleaning of aircraft parts.

Conclusions
‘The major conclusions of this case study are:

* The Bio-Tek product was eliminated after the
100-gallon tank test due to poor full-scale
cleaning efficiencies.

° 3-D Supreme outperformed Fremont 776 in the
cabinet spray washer tests. The cabinet spray
“washer operators stated that the 3-D Supreme
cleaned better than detergents currently in use.

« The organic-based solvents, Orange-Sol De-
Solv-It and Exxon Exxate 1000, were not tested
in the cabinet washer due to explosion hazards.

© Orange-Sol proved to be the best wax remover
in the 100-gallon tank test. Exxate 1000 was
also moderately effectively for wax removal.

© 3-D Supreme cleaned parts very well in the full-
scale tests, removing oil, grease and carbon well
enough for 81 percent on the parts to pass

normal Air Force inspections.  Eight-one .

percent equals or exceeds current standards.
One hundred percent of the parts with only oil
and grease passed.

¢ When soiled with oil, grease and carbon, 64

percent of the parts cleaned with the Fremor:
776 passed the inspections. The organic-based
solvents did not remove the oil, grease and
carbon as well as the water-based solvents.

© ‘Twenty percent of the Orange-Sol parts and 20
percent of the Exxate 1000 parts passed the
inspections. The organic-based’ solvents did
remove wax moderately.

« Some parts were successfully painted without
blasting, a normal paint preparation step.

¢ When introduced in quantity, the Fremont 776
product is the oniy product which will not affect
the industrial waste treatment plant. The other
solvents while biodegradable, require corrective
measures to prevent sludge flotation, and in
some cases to initiate biodegradation in the
activated sludge system.



6

Excise Tax

Congress has also placed an excise tax on ozone-
depleting chemicals manufactured or imported for
use in the United States. This tax provides a
further incentive to use alternatives and substitutes
to CFC-113 and MCF. The tax amounts are based
On each solvent’s ozone depleting potential.

Tax Amount
Per Pound
CFC-113. MCF

Calendar Ycar

1991 S1.096 0.137
1992 : $1336 $0.167
1993 $2120 $0,265.
1994 $2120 $0.65
1995 $2480  $0.310

The tax will increase by $0.310 per pound
for CFC-113 and $0.045 per pound for
MCF each year after 1995.

Other International Phaseout
Schedules

European Community Directive

Under the Single European Act of 1987, the twelve
members of the European Community (EC) are’
now subject to various environmental directives.
The members of the EC are Belgium, Denmark,
Germany, France, Greece, Great Britain, Ireland,
Italy, Luxembourg, the Netherlands, Portugal, and
Spain. Council Regulation number 594/91 of
March 4, 1991 provides Tegulatory provisions for
the production of substances that deplete the
ozone layer. The EC phaseout schedule for CFC-

113 production is more stringent than the”

Montreal Protocol. It calls for a 50 percent
reduction of CFC-113 by the end of 1993, a 67.5
Percent reduction by the end of 1995, an 85
Percent reduction by the end of 1996, and
complete phaseout by June 30, 1997. For MCF,

the production phaseout schedule is as follows: 30)
percent reduction by the end of 1995, 70 percent
by the end of 2000. and a complete phaseout by
the end of 2004, While all members Must abide by
these dates, Council Regulation number 3322/88 of
October 31. 1988 states that EC members may take
éven more extensive measures to protect the ozone

layer. °

Other Legislation

Several other countries have adopted legislation

that is more stringent than the terms of the

Montreal Protocot. Environment Canada, the

federal environmentat agency responsible for

environmental protection in Canada, also has a

reduction program in place that is more stringent

than the Montreal Protocol, _ All production and

import of CFCs, for use in Canada, must be '
eliminated by no later than 1997. Environment

Canada has also announced a series of target dates ©
for the phaseout of CFCs in Specific end uses. For

solvent cleaning applications, such as metal and

Precision cicaning, it mandates a phaseout of CFC-

113. by the end of 1994. Pending final

consultations with end-users and producers of

MCF, the target date for the phaseout of MCF will

be 2000.

Japan has ratificd the revised Montreal Protocol.
The recent Ozone Layer Protection Act gives the
Ministry of International Trade and Industry
(MITT) the authorization to promulgate ordinances
governing the use of ozone-depleting compounds. .
MITI and the Environmental Agency have
established the “Guidelines for Discharge
Reduction and Use Rationalization.” Based upon
these guidclines, various government agencies
provide administrative guidance and advice to the
industries under their Tespective jurisdictions,
Specifically, MITT, the ministry overseeing several
aspects of Japanese industry including the
Production and trade of controlled substances,
Prepares and distributes manuals, and encourages
industry to. reduce ozone-depleting compounds
consumption through economic measures such as
tax incentives to promote the use of equipment to
recover and reuse solvents.

The EFTA (European Free Trade Agreement)
countries (i.e., Austria, Finland, Iceland, Norway,



48

MISCELLANEOUS
SOLVENTS

The metal finishing industry has used a wide Tange
of solvents for cleaning. Some of the solvents,
commonly used, include:

* Ketones:

¢ Alcohols;

© Glycol Ethers;
¢ Esters; and

¢ Other chlorinated solvents.

The ketones form a group of very powerful
solvents (see Exhibit 15a). In particular. acetone
(dimethyl ketone) and ethy! methy! ketone are
good solvents for polymers and adhesives. In
addition, acetone is an efficient dewatering agent.
However, their flammability (note that acetone has
a flash point of 0°F) and incompatibility with many
structural polymers (¢g., stress cracking of
polyether sulphone, polyether ketone, and
Polycarbonate) means that they should only be
used with care and in small quantities.

Alcohols such as ethanol, isopropanol, and several
glycol ethers are used for a number of applications.
‘These solvents are chosen for their high polarity
and for their effective solvent power. The alcohols
have a range of flash points and care must be
exercised while using the lower flash point alcohols
(see Exhibit 15b). Solvents in this family,
particularly certain glycol ethers, can cause
swelling, cracking, and structural degradation of
polymeric and elastomeric materials. :

Esters, such as dibasic esters and aliphatic mono
esters, have good solvent properties. They offer
good cleaning for a variety of grimes and soils.
Most of these materials are readily soluble in
alcohols, ketones, ethers, and hydrocarbons, but
are only slightly soluble in water. Dibasic esters
have high flash point and low vapor pressure.
‘They are only slightly soluble in high paraffinic
hydrocarbons. Dibasic esters are so low in vapor

Pressure that a residual film will remain on a
surface after application. Aliphatic esters,
generally acetates, range in formula from ethyl
acetate to tridecyl acetate. The higher grades
(hexyi acetate and heavier) ‘are commonly used in
degreasing. They fall into the combustible or non-
combustible flash point range. They have
acceptable compatibility with most polymers.
These esters can be dried from a surface by forced
air drying with no residual film.

Other chlorinated
trichloroethylene, perchloroethylene, and.
methylene chloride also are effective cleaners.
However, trichloroethylene and perchloroethylene
have been shown to exhibit photochemical
reactivity and are regulated as smog precursors.
These substances also have been shown to be
carcinogenic to animals, and care should be taken
in their usc. Chlorinated solvents are subject to

hazardous waste regulations under the Resource

Conservation and Recovery Act (RCRA). Users
of these solvents must be aware of and comply
with all federal, state, and local regulations
governing use. storage, and disposal of these
materiais. In addition to being classified as
hazardous waste, these solvents are subject to
Teporting requirements under the Superfund
Amendments and Reauthorization Act (SARA)
Title III. Occupational exposure standards have
also been sct for the use of these solvents and
must he considered when selecting these
alternatives. Chlorinated solvents might be
selected substitutes for CFC-113 and MCF in some
cases. Recent developments in emission control
technology as described in the discussion of
HCFCs, might mitigate some effects ‘of these
substances. Exhibit 16 summarizes the properties
of these other chlorinated solvents, .

solvents such as.



$0

Greenhouse effect -- A thermodynamic effect whereby energy absorbed at the earth’s surface, which is normally
able to radiate back out to space in the form of long-wave infrared radiation, is retained by gases in the
atmosphere, causing a rise in temperature. The gases in question are partially natural, but man-made pollution
is thought to increasingly contribute to the effect. The same CFCs that cause ozone depletion are known to
be "greenhouse gases", with a single CFC molecule having the same estimated effect as 10,000 carbon dioxide
molecules. . :

HCFC -- An abbreviation for hydrochlorofluorocarbon.
HEC -— An abbreviation for hydrofluorocarbon.

Hydrocarbon/surfactant blend — A mixture of low-volatile hydrocarbon solvents with surfactants, allowing the
use of a two-phase cleaning process. The first phase is solvent cleaning in the blend and the second phase is
water cleaning to remove the residues of the blend and any other water-soluble soils. The surfactant ensures
the water-solubility of the otherwise insoluble hydrocarbon. Terpenes and other hydrocarbons are often used
in this application.

Hydrochlorofluorocarbon -- An organic chemical composed of hydrogen. chlorine. fluorine and carbon atoms.
These chemicals are less stable than pure CFCs, thereby having gencrally lower ODPs. .

Metal cleaning -- General cleaning or degreasing of metallic components or assemblies, without ‘Specific quality .
requirements or with low ones. .

Methyl chloroform -- See 1,1,1-trichloroethane.
ODP - An abbreviation for ozone depletion potential.

Ozone -- A gas formed when oxygen is ionized by, for example, the action of ultraviolet light or a strong
electric field. It has the property of blocking the passage of dangerous wavelengths of ultraviolet light.
‘Whereas it is a desirable gas in the stratosphere, it is toxic to living organisms at ground level (see volatile
organic compound).

Ozone depletion — Accelerated chemical destruction of the stratospheric ozone layer by the presence of
substances produced, for the most part, by human activities. The most depleting species for the ozone layer
are the chlorine and bromine free radicals generated from relatively stable chlorinated, fluorinated, and
brominated products by ultraviolet radiation.

Ozone depletion potential - A relative index indicating the extent to which a chemical product may cause
ozone depletion. The reference level of 1 is the potential of CFC-11 and CFC-12 to cause ozone depletion.
If a product has an ozone depletion potential of 0.5, a given weight of the product in the atmosphere would,
in time, deplete half the ozone that the same weight of CFC-11 would deplete. The ozone depletion potentials
are calculated from mathematical models which take into account factors such as the stability of the product,
the rate of diffusion, the quantity of depleting atoms per molecule, and the effect of ultraviolet light and other
radiation on the molecules. : .

Ozone layer — A layer in the stratosphere, at an altitude of approximately 10-50 km, where a relatively strong
concentration of ozone shields the earth from excessive ultraviolet radiation.

Saponifler - A chemical designed to react with organic fatty acids, such as rosin, some oils and greases etc.,
in order to form a water-soluble soap. This is a solvent-free method of defluxing and degreasing many parts.
Saponifiers are usually alkaline and may be mineral (based on sodium hydroxide or potassium hydroxide) or
organic (based on water solutions of monoethanolamine). .



CASE STUDY #2:
SELECTION OF
AQUEOUS PROCESS.
‘FOR CLEANING
COMPONENTS FOR
SOLENOID VALVES

Case Study #2 describes a program implemented
at Honeywell to select an aqueous cleaning process
for cleaning components of solenoid valves.

Honeywell, Skinner Valve Division. produces
solenoid valves for use in fluid control. The
majority of components are 300 and 400 series
stainless steels with some brass and aluminum.
Parts typically range in size from one-half inch in
diameter by one inch long to two inches in:
diameter by four inches long. Operations
performed include turning, milling, drilling,
threading, broaching, and welding. Valves are used ,
in a variety of applications such as gasoline pumps,
medical oxygen equipment. and Photocopying
equipment.

Current Process

The major cleaning objective is to remove cutting
oils and chips from blind holes. Final clcaning is .
performed prior to welding and assembly. All,
“ work moves through two vapor degreasers .
equipped with hoods, programmable hoists.
ultrasonics, and attached recovery stills. Parts are
degreased between operations and also before
assembly. Parts are racked in metal trays.
approximately 10 inches x 16 inches, loaded three |
at a time into a rotating basket. Typical trays hold |
40 to 200 parts depending on size. Total cycle
time is five minutes. Annual volume is 1.2 million
valves. Each valve contains five or six major

components and each component is degreased at :

least two to three times. This results in over 16.5
million parts passing through the degreasing
operations. Consumption of CFC-113 for 1989
was 54,000.Ibs.

Alternative Selection
Process

In response to the concerns with CFC-113, the
Environmental Health and Safety group at
Honeywell issued a policy for all divisions to
reduce usage and ultimately eliminate CFC-113. A
central group was formed to study the problem and
relay information and findings to other divisions.

It was decided to avoid any replacement of CFC.
113 with "in kind" HCFCs because of pending
legislation that would ultimately regulate these

‘solvents. In addition, HCFCs were not expected to

be in production until 1992 and would require
newer and more .expensive equipment. Costs of
HCFCs were expected to be at least oqal to or
greater than CFC-113.

Because there were no’ tight spaces to trap a
cleaning fluid (as there might be for surface
mounted clectronic components) the low surface
tension and high evaporative rate of CFC-113 were
not a factor. The cleaning of parts between
machining operations did not require a high degree
of cleanliness; removal of the bulk of the oil and
all of the loose chips would be sufficient.

Health and safety factors were considered. No
substance that was more toxic or presented a
greater health risk than the current process would
be accepted.

Lastly, cost was a large factor. It was established
through vendor tests that relatively inexpensive
equipment could fill the cleaning needs and still
achieve a less than two-year payback. .

‘At Skinner Valve, two engineers were given the
task of meeting the corporate goals. Using both
corporate resources and cleaning equipment
vendors, these engineers outlined the following
steps to replace CFC-113 as a metal cleaning fluid.
©. Develop an objective and guidelines;

¢ Identify information sources;

¢ Identify baseline what, why, where, how, cost;

« Establish current material flow;



30

Exhibit 7

CONFIGURATION OF AQUEOUS CLEANING PROCESS
IN THE METAL CLEANING INDUSTRY

Parts from
Manufacturing
Process
Wash Rinse Dryer:
Stage: Stage: ryer: cisenes
Heated Detergent Water: Room Tema ar | —Bie Pars Roaey
‘Solunon: Spray, Spray, immersion or Heated Air .
Immersion Production
Ultrasonics, etc.
Solution A LU)
Recirculation:
Filtering, Skimming
Periodic Removal fami Waste Treatment |-3e| POTW

Source: EPA 1989a



| 42

Exhibit 11b

STACKED LOW EMISSION DEGREASER WITH
SOLVENT SAVING FEATURES

Source: ICI

Convection
* Closing Lid —— ed S Break
° ° Standby
Free
Refrigerated QO, o} Mode
Freeboard ——To Board ©} Defrost
Inter Coil of F.B.R.=1 °
Battle — |e of Trough
Four Sided Joo oo
Cascade joo Ke}
Condensing L291 Vapor if
5 us cal
& Mii Cool
S /Aiquid/4 Down
Qo
5 YH Wf; g Coil
Yl ML Lisak
Ui OVAL
Solvent Saving
Features

(not shown)

Screwed pipe joints

Correct sealing material

Correct pump seals « ...

‘Minimum number of -

pipe joints

Degreaser enclosure

Mechanical handling with
optional rotation

Correct size basket

tst31-2



47

soil level builds up. Fresh solvent is added only to
the final bath to ensure the highest cleanliness of
parts, and spent solvent is removed only from the
first stage.

The drying step normally uses forced air, which
may be heated. Either the dryer should operate at
15°C below the flash point of the fluid, or
sufficient air flow should be provided so that the

chosen, either carbon adsorption or condensation
are the best technologies for recovering solvent
vapors from spent drying air and lip vent air.
Numerous vendors market this type of recovery

* equipment.

In the waste recovery area, the best reclamation.
technology for these products is usually filtration
and distillation. One of the advantages of the low
olefin content and narrow distillation range is that

effluent air composition is well below the Lower
Explosive Limit of the system. ' the recovery in distillation is high, Should some
disposal of residual solvent be necessary, fuel
The VOC recovery step is an important part of the substitution or incineration are good routes.

cleaning process. Depending on the solvent

Exhibit 14

PROPERTIES OF ALIPHATIC SOLVENTS

PRODUCT Lb/Gal. | Sp. Gr. Boiling .
60°F 60°/60°F =| Range *F | *F TCC KB Rate!
Mineral Spirits 6.37 0.764 305-395 105 2 0.1
Odoriess Mineral Spirits 6.33 0.760 350-395 128 2 0.1 4
140 Solvent 6.54 0.786 360-410 140 30 0.1
C10/C11 Isoparaffin 6.25 0.750 ° |. 320.340 107 29 03
C13 N-Paratfin 6.35 0.760 320-340 200 2 0.1
C10 Cycioparatfin 6.75 0.810 330-360 105 54 02 |
Kerosene 6.60 0.790 330-495 30 - |

1 n-Buty! Acetate=1
Note:

KB = Kauri Butano! Value
Fi. Pt. = Flash Point



Exhibit I1c

ADVANCED DESIGN DEGREASER FOR
USE WITH LOW BOILING POINT SOLVENTS

=

Turned-In. ——» |
Anti-Diffusion

Lip
~—a— Freeboard
Depth = 1" Gasketed

Vapor Trap —__ » |, +— Desiccant

(optional in Le “T Dryer with

many cases) =a6 “sOP-Trap
-209 F to 40°F be pe

FE Nn

Main Condensor hy

35°F : ; AU
“Y Y Desiccant ;
7 7 ;
. Vapor Generator —> YUU. =a— Rinse Sump
” Sump LG,

Heating Elements

“Machine Width = w; w = 1 Indicates 100% Freeboard

Source: Allied-Signal

a ns1913

ae



72

CASE STUDY #3:

A FIVE-PHASE PROGRAM
FOR DEVELOPING
ALTERNATIVE CLEANING

Case Study #3 is an overview of the progress made

by General Dynamics Fort Worth Division
(GD/FW) to eliminate halogenated solvent vapor
degreasing and MCF ambient immersion cleaning.
After establishing a working team with
representatives from all functional departments in
1987, criteria were established to. identify
acceptable alternatives and concrete goals and
milestones were set. The project was divided into
the five phases discussed below.

Phase I -- Soil, Cleaner, and
Parts Identification/
Characterization

In Phase I, the soils and production operations
that generate parts requiring degreasing were
characterized. Concurrently, the chemist on the
team began identifying alternative cleaning
materials and processes. Formulations that
contained any hazardous or restricted constituents
were excluded as well as materials which could
emit VOCs or toxic air emissions. .

Phase II -- Cleaner
Evaluation and Optimization

The Phase II evaluation focused on cleaning
capability using a combination of water break,
ultraviolet light, and acid copper immersion to
determine cleanliness. Over fifty commercially
available aqueous detergent and emulsion cleaners,
nine terpene hydrocarbon formulations. and several
CFC-113 blends (for comparative purposes) were
screened. Concentrations and temperatures were
varied for three fixed immersion periods. Cleaners
were also tested for any gross corrosion or adverse
effects on materials. Six products were selected by
mid-1988. Five were selected as general degreasing

substitutes. The sixth, a terpene hydrocarbon, was
selected as an option for removing high-molecular-
weight (asphaltic or paraffinic) soils. ,

Phase III -- Performance
Confirmation and Materials
Compatibility Evaluation

In Phase III, the five general degreasing substitutes
were evaluated in detail for compatibility with
substrate materials, surface coatings, adhesives,
bonding materials, and downstream metal finishing
Processes. (These evaluations were similar to
those shown in case study #1.) Compatibility with
a variety of honeycomb core materials and
laminates was also examined. Three materials
were sclected as candidates for — further
investigation as general degreasing substitutes,
Additional options for heavy asphaltic soil removal
were developed. and ultrasonics was investigated to
facilitate cleaning of tubes and heavy asphaltic
soils.

Phase IV -- Pilot-Scale
Performance, Factory
Evaluation

The Phase IV factory evaluation and pilot study of
the final three candidate materials began in mid-
1989. In Phase IV,.laboratory performance was
confirmed on production-sized parts, longer-term
operational stability of the solutions was
investigated, foaming characteristics were
examined, operating and maintenance procedures
were developed, an economic analysis was
conducted, and a toxicological and environmental
impact assessment was performed.

Phase V -- Development of
Recycling Process

In Phase V, several engineers screened oil removal
technologies and selected a recycle process based
on a ceramic membrane ultrafiltration for further
investigation. The three products were approved



82.

Exhibit 18

AQUEOUS PROCESS FOR CARBON STEEL

CHAIR PARTS

Parts Load/
Unload

Monorail Ory

nei



aAaNnan

a

When using concentrated hydrocarbon/surfactantin
immersion equipment, ‘spray-under immersion"
can be performed. In this equipment. high
pressure spray nozzles are placed below the surface
of the liquid. This prevents the formation of
atomized solution and decreases. flammability.
Mechanical agitation. workpiece movement. and at
properly designed ultrasonic agitation may also be
used.



ALTERNATIVES FOR CFC-113 AND METHYL CHLOROFORM
IN METAL CLEANING

by

ICOLP Technical Committee*

Eari Groshart (Chairman)
George Bohnert
Charles Carpenter
Stephen Evanoff
John Golden
Greg Hollingsworth
Stewart Holm
Michael Oborny

Farzan Riza .
Ronald Stephenson

Stephen O. Andersen
U.S. Environmental Protection Agency

.

* ICOLP is the Industry Cooperative for Ozone Layer Protection. ICOLP corporate member companies include AT&T, Boeing Company,
British Aerospace, Compaq Computer Corporation: Digital Equipment Corporation, Ford Motor Company, General Electric. Hitachi
Limited, Honeywell. IBM. Matsushita Electne Industrial Company. Mitsubishi Electric Corporation. Motorola, Norther Telecom,
Sundstrand, Texas Instruments. and Toshiba Corporation. Industry association affiliates include American Electronics Association,
Electronic Industries Association. Japan Electrical Manufacturers Association and Halogenated Solvents Industry Alliance (U.S.).
Government organization affiliates include the City of Irvine. California. the State Institute of Applied Chemistry (U.S.S.R.), the Swedish
National Environmental Protection Agency, U.S. Air Force, and U.S. Environmental Protection Agency (EPA).

Earl Groshart, John Golden and Ronaid Stephenson are employed by Boeing; George Bohnert is employed by Allied Signal Aerospace;
Stephen Evanoff is employed by General Dynamics: Stewart Holm is employed by Halogenated Sotvents Industry Alliance: Greg
Hollingsworth is employed by Honeyweil: Farzan Riza is employed by ICF Incorporated: Michacl Oborny is employed by Sandia National
Laboratones: and Charles Carpenter is employed by the U.S. Air Force. We would like to thank the many individuals and companres that
provided insight and information that helped produce this manual. This manual was funded by the U.S. EPA and ICOLP.



60



46

ALIPHATIC
HYDROCARBONS

There is a wide range of aliphatic hydrocarbon
solvents that can be used in metal cleaning (see
Exhibit 14). Petroleum fractions, commonly
known as mineral spirits or kerosene, are used
extensively in maintenance cleaning (e.g. auto
repair). These operations are single stage, open
top processes using ambient air drying. In most
Cases such processes are not suitable for original
equipment manufacturing cleaning. Synthetic
aliphatic hydrocarbons, which offer closer control
of composition, odor, boiling range, evaporation
fate, etc., are employed in OEM cleaning processes
and will be discussed helow.

The advantages of aliphatic hydrocarbon cleaners
include:

« Good cleaning ability for a wide variety of soils,
especially heavy grease, tar, waxes and hard to
remove soils. Low surface tension allows good
penetration.

« Compatible (non-corrosive) with most rubbers,
plastics and metals. .

« They employ no water, hence can clean water
sensitive parts.

© Low odor and low toxicity grades available.
» Reduced evaporative loss.
© No wastewater stream.

¢ Recyclable by distillation. High stability and
recovery.

‘The disadvantages include:

« Flammability concerns. However, these
concerns can be mitigated with proper
equipment design.

© Slower drying times than halogenated solvents.

¢ VOC control may be required. However,
equipment, such as carbon adsorption and

condensers, exist to recover solvent from
effluent air.

* Some grades have low Occupational Exposure
Limits. :

‘The steps in a typical hydrocarbon cleaning process
are analogous to aqueous or semi-aqueous
Processes. Equipment designs for use with hydro-
carbons are modified aqucous equipment designs.

The major steps in the cleaning process ‘are
typically:

+ Wash steps (1 to 3 stages depending on degree
of cleaning needed) with a hydrocarbon cleaner;

« Drying step, using forced air;

« VOC recovery from sc-vent: laden air, if
required: and

« Waste solvent recovery or disposal.

The wash steps involve liquid-phase cleaning at
temperatures sufficiently below the flash point of
the fluid. Ultrasonics or other agitation processes
such as immersion spraying. parts rotation or fluid
pumparound can be uscd to augment cleaning
action. Spraying or misting processes, where fine
droplets arc formed, should be employed only in
an inert environment or with equipment with other
protection against ignition conditions. This
Protection is required because fine droplets canTM
ignite at temperatures below bulk fluid flash point.

Fluids with flash points near.40°C (104°F) should | =

be operated in unheated equipment, at ambient
temperatures. For higher flash points, hot clean-
ing can be employed to boost cleaning action. For
systems with good temperature contro! (indepen-
dent temperature sensors, cutouts, level indicators,
etc.), a safety margin of 15°C (27°F) between the
fluid flash point and the cleaning temperature is
recommended. For systems with poorer tempera-
ture, control, a larger margin should be employed.

Each wash step should be followed by a drain
period, preferably with parts rotation, to minimize
solvent dragout from stage to stage.

In multistage processes, fluid from one bath is
periodically transferred to the preceding bath as its





20

Chemical Cleaning Ability

‘The question of cleanability can be the source of
Many hours of meetings, discussions. and testing.
The degree of cleanliness required varies from
industry to industry and from process to process.
In some metal cleaning applications. cicanliness
Tequirements are less stringent in terms of
measurable residue while in industries where
Critical components are being cleaned,
Tequirements may be more stringent. Meeting
Cleanliness standards in the aerospace industry may
require the removal of all damaging contaminants.
‘The high performance coatings and adhesives used
On jet aircraft require, for example, a high degree
of surface cleanliness to insure the integrity of the
coatings and to guarantee that adhesives are not
adversely affected.

The removal of contamination trom a surface 1s
not a single property of a soivent, but a combined
relationship of several characteristics. Some of
these characteristics include wetting, capillarity,
detergency, solubility, and emulsification.

Several standard tests can be used to determine the
cleaning ability of the alternative process. Some of
these tests can be run on the shop floor (visuais,
tissue paper test, water break, and acid copper
test), whereas other tests would have to be
performed in a laboratory.

¢ Visual Examination. This test is useful only for

visible contamination. but it can be done in a *

production/plant environment.

«© Tissue Paper Test. The cleaned surface is rubbed
with white tissue paper and the tissue is
Observed for stains. This test is simple and can
be done in the production/plant environment.

¢ Woter Break. If the last clean rinse forms a
continuous water film on the part as it is
removed, the surface can be considered clean.

Acid Copper Test. A ferrous panel is immersed
in a copper sulfate solution. On clean surface
areas, copper will be deposited by chemical
activity, forming a strong adherent. semi-bright
coating that is spot free.

¢ Atomizer Test. Water mist is applied to a clean
dry surface with an atomizer. The cleanliness is

.

determined by the value of the advancing
contact angle.

Contact Angle of Water Drop. A drop of water is
Placed on the test surface: the contact angle is
then measured either photographically or by a
contact angie goniometer. Although this is an
accurate method of determining relative surface
cleanliness. it can only be used under laboratory
conditions.

Kerosene Viewing of Water Break. The test panel.
is withdrawn from water and is immediately
submerged in a transparent container of
kerosene that is lighted from the bottom.
Water breaks are displaced by kerosene.
(Kerosene is combustible. so be careful when
using this method.)

Radioactive Tracer. A radioactive soiling
compound is applied to the test piece. and the -
Tesidual radioactivity is measured after cleaning.
This is the most scnsitive of the quantitative
tests now available. Use standard precautions
when working with radioactive materials.

Fluorescent Dye. An oil soluble fluorescent dye
is mixed with an oily soiling material and
applied to the test panels. After the panels are
cleaned. the retained soil is visible under
ultraviolet or black light. Note that some
cleaners may selectively remove tracer or
fluorescent dyes. . :

Gravimetric. The test panels are weighed before
and after cleaning. The sensitivity of the
method depends upon the sensitivity. of the
balance and the size of the panel.

Oil Spot. A drop of solvent is used to degrease
an area the size of the drop. The drop is picked
up with a pipette and evaporated on ground
glass. An evaporation ring indicates contamina-
tion,

Particulate Contamination. A thin film of
polyvinyl chloride is pressed against the test
surface, heated to 240°F, and cooled. It is then
carefully stripped from the surface and
examined under the microscope. The
particulate contaminants will be embedded in
the vinyl sheet.



16

METHODS TO ELIMINATE THE NEED FOR CLEANING

Soil Presently Removed
by Chlorinated Solvent

Methods Which Reduce Solvent Use

Hydraulic Fluids - Phosphate
Esters

Magnetic Inspection Field -
Kerosene

Hydrocarbon Greases and
Oils

Fats and Fatty Oils
Polishing Compounds -- Fats
Machining Compounds --
Cutting Fluids

Corrosion Inhibiting
Compounds

Drawing Compounds
Forming Compounds
Ink Marks

Fingerprints

Mill Oils

Prevent spills and leaks. Sorbent materials can be used.
Sorbent materials can be used. Water carriers to teplace the
organics can be considered.

Hand wiping stations can remove enough material to allow
alkaline cleaning. Water soluble compounds can be used.

Handwipe or use alkaline cleaners.

Water-soluble compounds may he substituted. Cleaning at the
polishing station should be considered.

Water-soluble compounds should be considered.

Alkaline-soluble compounds can be considered. Protective packaging
may eliminate cleaning need.

Water-soluble compounds can be used.

Water-soluble compounds can be used.

Water-soluble inks can be used and removed with water-based
cleaners. Use labels or tags until final marking applied.

If all fabricated parts are handled with gloves. fingerprints will be
minimized. Hand alkaline wipe to remove. ’

Protective packaging eliminates cleaning need. Sorbent materials
may be used to remove oils.



28

AQUEOUS CLEANING

Aqueous cleaners use water as the primary solvent.
Synthetic detergents and surfactants are combined
with special additives such as builders. pH buffers.
inhibitors, saponifiers, emulsifiers, defloccutants.
complexing agents, antifoaming agents. and other
Materials. These agents provide multiple degrees
of freedom in formulation. blending, and

concentration, and provide useful synergistic
effects, Exhibit 6 presents an overview of the
advantages and disadvantages of aqueous cleaning.

‘The key stages of an aqueous cicaning
process are (see Exhibit 7):

« Washing
¢ Rinsing
¢ = Drying

Wastewater Treatment and Disposal

Although each of these steps is an important and
integral part of the aqueous cleaning process.
rinsing and drying may not be necessary in all
circumstances and wastewater disposal may be
completely integrated into other steps through the
use of recycled baths.

Process Design and
Implementation

To implement an aqueous cleaning process,
conduct an overall evaluation of the following:

¢ The cleaner’s effectiveness (i.e., whether it has
good cleaning chemistry for your needs);

« The process equipment mechanical

considerations);

(ie,

« Other process characteristics (e.g. werting
agents).

Process Chemistry

Aqueous cleaners are comprised basically of three
major types of components: (1) the builders which
make up the largest portion of the cleaner, (2) the
organic and inorganic additives which promote
better cleaning or affect-a metal’s surface, and (3)
the surfactants and wetting agents.

As we noted earlier, being able to tailor the
cleaner formulation gives aqueous cleaning great
flexibility. Molecular structure, which has

significant effects on the properties, can be varied °

over a wide range. For example, the number of
carbons on the molecule (whether straight chain,
branched chain. or ring structure) and the ratio of

the hydrophilic to hydrophobic moiety can be ~

tailored to achieve the desired

requirements.

cleaning

Builders arc the alkaline salts in aqueous cleaners.
They are usually a blend selected from the
following groups: alkali metal orthophosphates and
condensed phosphates, alkali metal hydroxides,
silicates, carbonates, bicarbonates, and borates. A
blend of two or more of these builders is typically
used in aqueous cleaners.

Phosphates are the best overall builders. However
discharge of cleaning solutions containing
phosphates is subject to environmental regulations.
Chelating agents such as ethylenediamine tetra
acetic acid (EDTA) and nitrates can be used

* instead of phosphates. Silicates are sometimes

difficult to rinse and may cause trouble in
subsequent plating operations if not completely
removed. Carbonates and hydroxides are cheap

sources of alkalinity and are also effective builders.

Additives are either organic or inorganic
compounds that provide additional cleaning or
surface modifications. Chemical compounds such,
as glycols, glycol ethers, chelating agents, and
polyvalent metal salts, could be considered
additives. Some of these materials could be
subject to VOC concerns.





70

¢ Identify equipment options;
¢ Run test on vendors equipment:

* Compare test results between different type of
cleaning machines;

¢ Identify cleaning solution options:
Identify waste handling options:

* Perform financial analyses; :

© Order Phase I equipment:

« Install and debug equipment:
Review results of Phase | equipment:
¢ Order Phase II equipment: _

Install Phase If equipment: and

© Obsolete vapor degreasers.

Cleaning Requirements

The factory has been restructured into a cell
concept with Just in Time (JIT) manufacturing.
This structure required decentralized degreasing
operations, preferably units small and inexpensive
enough to place one at every work station.

Several different levels of cleaning are required.
These were broken down into three levels:

Level 1 includes those parts that must be
completely cleaned with no oil or chips and
completely dry with no residue, "Oxygen service"
Parts are the most demanding since they will be

used in oxygen regulators and medical equipment. .
No hydrocarbons can be allowed. Inspection is

done under ultraviolet light and the cleaned parts
are handled with cotton gloves and placed in
Plastic bags until final assembly.

Level 2 includes normal cleaning prior to assembly
or welding. Parts must be free of dirt and oil, with
no chips, and dry.

Level 3 includes parts primarily between
Operations and is intended to remove the bulk of

the oil and chips so that a part can be handled and
located for the next operation. Depending on the
next operation, it is not necessary for the part to
be dry, for example, tumbling and passivation, .

Ranking the work by levels provided a better
breakdown of the numbers involved and how many
locations and types of machines would be tequired.
Tests were performed on representative samples of
the different types of parts and the different levels
of cleaning required.

After the decision was made to use an aqueous
system, the question of waste material was still a
major concern. Options included shipping waste
solution and rinse water off site; this was Tejected
as being too expensive. On-site treatment was a
less costly answer.

Honeywell considered on-site treatment and
disposal into the sewer which would require
constant monitoring and wouid become more .
difficult as more facilities attempted to discharge
aqueous wastes to the sewer. Other treatments
considered included ultrafiltration and evaporation.
Evaporation was chosen for this application
because rinse water volumes were low and the
absence of a liquid waste stream limited the risk of
spills and avoided the possibility of exceeding
treatment limits.

General Description

The approach taken was to select the equipment ~
first and then find the best cleaning solution for .
each application. The selection of cleaning
solutions is still in progress. The preference of
this team is to use one of the nonemulsifying
cleaners to facilitate oil separation. ~ *

Three separate systems were selected: mechanical
agitation, spray washers, and ultrasonics.

Mechanical Agitation

In general these units consist of a tank with a
movable rack. The rack is set to submerge the -
work piece in a heated solution and move the work
piece up and down a set frequency. Working
temperatures range from room temperature to



22

* Sandwich corrosion (ASTM F1110) testing
measures the corrosivity of a cleaner trapped
between fraying surfaces and then periodically
exposed to various temperature and humidity
conditions.

* Hydrogen embrittlement (ASTM FS519-77)
testing is conducted to determine if cleaners will
adversely affect high strength steel. Testing can
be conducted in accordance with ASTM F519,
using both cadmium plated and unplated Type
1A steel specimens. The specimens are
Subjected to 45 percent of their ultimate tensile
strength while immersed in the test solution.
The specimens must not break for a minimum
of 150 hours.

Effect on Subsequent Processes

Since cleaning is an integral part of manufacturing
processes, it is critical that you examine the effect
of cleaning on subsequent manufacturing steps.
These include:

* Application of Protective Coatings. Cleaning is
used extensively before and after the application
of protective and/or decorative finishes. For
example, surfaces cleaned before painting,
enameling, or lacquering, give better adhesion
Of finishes. Similarly, cleaning is used to
remove large amounts of oil contamination.
prior to electroplating.

© Inspection. Inspections may be numerous,

making speed and ease of part handling very ©

important. Parts are cleaned to meet customer
Tequirements and have to be inspected to
identify any defects.

¢ Assembly. Assembly requires that parts be free
from inorganic and organic contaminants. The
Cleaning process should leave the parts clean
and dry, ready for assembly, and/or subsequent
finishing.

© Further Metal Working or Treatment. In many
instances, parts must be prepared for
subsequent operations such as welding, heat
treating, or further machining. Cleaning
between steps allows the operator to start each
new step with clean, dry parts. Before heat
treatment, all traces of processing oils should be

Temoved from the surfaces: their presence
causes smoking. nonuniform hardening, and
heat treatment discoloration on certain metals.

¢ Machining. By starting a machining operation
with a clean surface. the chance of carrying
imperfect parts through to other Operations is
minimized. Cutting oils used during machining
give best results when applied to clean surfaces.

* Packaging. Final cleaning prepares parts for
packing and shipping.

Process Control

Process control is part of a quality assurance
program. Being satisfied with a process is key to
a successful program. One exampie of good
Process control is checking cleaner solution
strengths on a routine basis. Maintaining solution
strength by making small, frequent additions is
much more effective than making a few large
additions. :

Throughput of the Cleaning Process

Cleaning process throughput can be an important
parameter. especially if cleaning is part of a
continuous production process. For example,
adhesion of finishes can be affected by moisture
Temaining on a surface to be coated. The rapid
drying time associated with solvent cleaning
Provides an advantage in speeding up production
Processes. For hatch cleaning processes, this factor

may not be critical. “Some alternative process may...

require slower for optimized

operations.

throughput

Ease of New Process Installation

Another consideration is whether the current

manufacturing operation is flexible enough to
allow installation of a new process. Would it be
easy or would it disrupt the current process?

Floor Space Requirements

Equipment must be compatible with the plan and
space constraints of your manufacturing floor. A



88

KLN Ultraschall GmbH
Siegfriedstr. 124
D-6148 Heppenheim
Germany

Tel: 6252/14-0
Teletex: 625290

Fax: 6262/14-277

Streckfuss USA, Inc.
3829 W. Conflans
P.O. Box 153609
Irving, TX 75015-3409
Tel: (214) 790-1614



3

Section 604 and Section 605:
Phaseout of Production and
Consumption of Class | and Class i
Substances.

These provisions of the CAA present phaseout
schedules for Class I & Class [I substances. The
phaseout dates for ozone-depleting substances
listed in the CAA are more stringent than the
Montreal Protocol. Exhibit 3 presents the
pPhaseout schedule for CFC-113 and MCF. Other
substances with ozone-deleting potential.are also
Teguiated under the Montreal Protocol and the
CAA. While they are not used in solvent cleaning
applications, these substances are used in other
applications. Section 605 of the CAA presents
provisions for the phaseout of HCFCs. The CAA
freezes the production of HCFCs in 2015 and
phases them out by 2030. Since these restrictions
focus on production limitations. to the extent that
these chemicals can be recovered. recycled. and
reused, they may continue in commerce past the
applicable phase-out dates.

Section 608: National Emissions
Reduction Program

This section calls for EPA to promulgate
regulations by July 1992 requiring emissions from
all refrigeration sectors (except mobile air
conditioners that are covered in Section 609) to be
reduced to their “lowest achievable levels."
Regulations affecting emissions from all other uses
of Class I and Class II substances including solvent
cleaning are to take effect by November 1995.
This section also prohibits any person from
knowingly venting any of the controiled substances,
including HCFCs, during servicing of refrigeration
or air conditioning equipment (except cars)
beginning July 1, 1992, and requires the safe
disposal of these compounds by that date.

' Section 610: Nonessential Products
Containing Chlorofluorocarbons -

This provision directs EPA to promuigate
regulations that prohibit the sale or distribution of
certain “nonessential” products that release Class I
& Class iI substances during manufacture, use,

storage, or dispasal. In the CAA. Congress defined
several produces as nonessential including CFC-
containing caning fluids for noncommercial
electronic and photographic equipment, and CFC-

. propelled plastic party streamers and noise horns.

In addition. Congress established guidelines to
identify additional products that are nonessential.
Regulations banning nonessential products that
Telease Class I sabstances must be promulgated by
November 15, 2991 and become effective Novem-
ber 15, 1992. In addition, the CAA bans the sale
and distribution of certain products reieasing Class
I substances. iaciuding aerosols and pressurized
dispensers and noninsulating foam. by January 1,
1994. Exempoons can be granted from the ban on
aerosois and pressurized dispensers due to
flammability aed worker safety concerns.

Section 611: Labeling

This section of the CAA directs EPA to
promulgate regulations by May 15, 1992 requiring
labeling of products that contain or were
manutactured with Class I or Class II substances
and containers containing these substances. The
label will read “Warning: Contains or manufac-
tured with [insert name of substance}, a substance
which harms pablic health and environment by
destroying ozone in the upper atmosphere”.

The CAA defines three types of products that must
be labeled and specifies the time frame by which
these products must be labeled. The three
products and time frame are as follows:

= Effective May 15, 1993, containers in which a
Class I or Class II substance is stored or
transported, and products containing Class I
substances must be labeled;

« Effective May 15, 1993, products manufactured
with Class I substances must be labeled.
However, products manufactured with Class I.
substances can be temporarily exempted from
the labeling requirements of this section if EPA
determines that there are no substitute products
or manufacturing processes that (a) do not rely
on the use of the Class I substance. (b) reduce
the overall risk to human health and the
environment. and (c) are currently or potentially

available. If EPA temporarily exempts products



71

180°F; agitation can be varied with respect to
length and speed of the stroke. One system
purchased also contains a heated rinse. Oil
skimmers are either belt or disk type units with a
separate secondary oil-water separator. Trays are
filled at the rate of one every 15 minutes: the
operator places the tray onto the work rack and
starts a five-minute cycle. Solution temperature is
set at 135°F, The parts are oriented to prevent
cupping and dragout. At the end of the wash
cycle, trays are either put through a rinse cycle or
are allowed to dry and cool. i

Spray Washers

Units consist of a small conveyor that passes parts
under a series of high pressure spray nozzies.
After washing, parts are passed under an air knife
to blow off excess. solution,, Parts are then
dropped into baskets and moved to the next
operation. The bulk of these parts continue on to
other “wet” operations such as tumbling and
passivation. Working temperature is 135°F. A
disk type oil separator is utilized.

Ukrasonic

Ultrasonic cleaners are reserved for the highest
level of cleanliness. For critical parts, a prewash in
an agitating washer is used. An immersion tank
with bottom mounted transducers providing 1,400
watts input is used. A four- to five-minute cycle at
135°F followed by a three-bath counter flow rinse
is utilized. Parts are then dried in a heated tunnel
or a top loading oven. ‘

Key items necessary to implement technology
e Upper management support. ;

« Shop support. It Was necessary to work with
operators and supervisors to integrate the
aqueous cleaning process. :

« Time allocation. Sufficient time was allocated
to do the necessary research and
experimentation to find the best available
technology. 1

Costs of Technology

Total costs for the existing CFC-113 cleaning
system and a projected cost for the replacement
system was established. Material costs were based
on current consumption and price of CFC-113.
The consumption estimate incorporated reductions
in CFC-113 use. resulting from conservation
practices adopted at Skinner Valve. However, the.
CFC-113 price calculation did not take ‘into
account the future price increase and the excise
tax.

Additional costs items included waste removal and’
utility costs. Labor costs were assumed not to
change. Salvage value of vapor degreasers was
taken as zcro, since it was difficult to. determine

_ what if any market value they might have.

Cycle times for aqueous processes are usually
longer and throughput rates are lower, However,
aqueous machines costs less than vapor degreasers,
thus allowing the purchase of multiple units.

The largest savings occur in material costs.
Cleaner cost for one machine were estimated at
$35 to $50. This is based on the utilization of the
cleaner for up to one month. Actual use shall
depend on the volume and type of soils being
removed. Costs of the aqueous cleaner is about
the costs of two gallons of CFC-113.

Based on the project equipment list and current
CFC-113 cost, Skinner Valve expects to have a
payback period of less than one and half year. If
existing vapor degreasers can be sold or transferred
to another division, payback will be even shorter.



ai

7

alternative to vapor degreasers now in service.
The solvent is effective in removing oils. grease
and carbon deposits but should not be considered
for wax removal. For both 3-D Supreme and
Fremont 776 rinsing the parts with steam or high
Pressure spray at intermediate points in the
cleaning cycle would enhance the cleaning
Substantially and reduce the overall cleaning-cycle
time. ,

The major drawback in using 3-D Supreme is the
impact of disposal of used baths on the solids
contact clarifier (SCC) sludge bed at the IWTP.
The 3-D Supreme causes the SCC sludge to float.
Several solutions to this problem are the addition
of small amounts of ferric chloride (FeCl3) to the
IWTP process stream: or replace the current
polymer addition with an iron bearing polymer.
The operator time and chemical and equipment
expenses involved could be costly.

Tt is necessary, when disposing of used 3-D
Supreme through an activated sludge system. to
maintain a constant feed source to acclimate the
bacteria to the material. The microorganisms in
the activated sludge (AS) basin feed mostly on
Phenol and to a lesser extent on other organic
constituents in the wastewater. As long as phenol
is intermittently available, the organisms will feed
on it and will not acclimate to removing other
Organic constituents as efficiently or completely.
Given the constant availability of 3-D Supreme,
the organisms would acclimate, as evidenced by
reduction in COD and TOC concentrations in the
éight-day tests. However, large fluctuations of

“phenol concentrations would hamper that

adjustment. If the solvent were stored and fed into
the system continuously, the microorganisms
should acclimate and degrade the material.

Fremont 776. The Fremont 776 is in use in a
cabinet spray washer, which has been used for
cleaning fuel control assemblies. The solvent did
not remove molybdenum disulfide grease or wax
and did not seem to emulsify the hydraulic oil The.
full-scale test results showed Fremont 776 being
less effective than 3-D Supreme as a cleaner,
However, the product performed adequately on
oils, grease and carbon soil. The major advantage
of Fremont 776 is that it can be released to the
industrial wastewater system and treated at the
IWTP without modification of the processes in
that facility. :

Orange Sol De-Solv-It. | When enhanced with
agitation and elevated tcmperature. Orange Sol,
De-Soly-It is a moderately effective wax remover.
The jar tests demonstrated that neither ferric
chloride nor aluminum suifate couid prevent the
SCC sludge from floating when Orange-Sol was
present. For this reason. Orange-Sol should not
be added to the Tinker AFB wastewater systems
unless the oil and water separator can be shown to
femove the material. Attempts to emulsify the
Orange-Sol in the jar tests using a high-speed .
blender were ineffective. Being that resistant to
emulsification speaks well for its removal by the oil
and water separation system. A study to determine
how De-Solve-It effects the oil-water separator will
be conducted. Another consideration is that
Orange Sol De-Solve-It is expensive, $14.90 per
gallon.

Exxon Exxate 1100. Exxate 1000 proved moderately
effective fof removing wax and could be used in
applications such as those described for the
Orange-Sol. Application of Exxon’s Exxate 1000
has several drawbacks. First, floating the sludge of
the metals treatment system occurred, the same
problem as with the Orange-Sol. Concentrations
of ferric chloride, high enough to ensure the SCC
sludge would settle, lowered the pH to a level that
was harmful to the activated sludge. Unless the
ferric chloride treatment were coupled with a pH
adjustment downstream for the SCC, the activated
sludge system would be upset. Low pH conditions
would also shift the metal precipitation
equilibrium. raising the concentration of heavy
metals downstream from the SCC. For these
reasons, the ferric chloride treatment is not
recommended for use with Exxate 1000.

Aluminum sulfate was successful in preventing the
floatation of the SCC sludge, with Exxate 1000
Present in the waste stream, but the: method is
costly. The chemical and its handling would be
expensive, and the amount of SCC sludge would be
increased substantially.

Additionally, considerations are: the distinctive
odor of the solvent resulted in complaints of
headaches and other discomfort and may require
special ventilation considerations; like Orange-Sol,
the De-Solv-It, the Exxon product is expensive,
$6.24 gallon: the pilot-scale run data demonstrated
that the solvent biologically degraded and did not
disrupt the activated sludge basin operation.



Exhibit 1
Exhibit 2
Exhibit 3

Exhibit 4
Exhibit 5
Exhibit 6
Exhibit 7

Exhibit 8
Exhibit 9
Exhibit 10
Exhibit lla

Exhibit 11b
Exhibit lic

Exhibit 12
Exhibit 13
Exhibit 14
Exhibit 15a
Exhibit 15b
Exhibit 16
Exhibit 17
Exhibit 18

List of Exhibits

Montreal Protocol Participants ......... panececces ars
Corporate Policies on CFC-113 Reduction Schedule
Phaseout Dates for CFC-113 and Methyl Chloroform Under the

US. Clean Air Act and the Montreal Protacol .......... cece ee ee ee 4
CFC-113 and Methyl Chloroform Usage Profile .................. 14
Methods to Eliminate the Need for Cleaning .................005 ‘16
Aqueous Cleaning: Advantages versus Disadvantages ............. 29

Configuration of Aqueous Cleaning Process in the Metal
Cleaning Industry ................-. eee eee eee een eene

Aqueous Cleaning Process Equipment .............-.004.
Semi-Aqueous Process tor Immiscible Hydrocarbon Solvent .
Physical Properties of HCFCs and Other Solvent Blends ............
Advanced Design Degreaser tor Use with Low Boiling Point
Solvents 0.22... cece cee etc eeeee eee ete este eeeees 41
Stacked Low Emission Degreaser with Solvent Saving
Features 0... eee ec cece cette ee eect eee eeeerenees 42
Advanced Design Degreaser for Use with Low Boiling Point

SS 0) 0 43
Summary of Properties of N-Methyl-2-Pyrrolidone . . -.. 44
NMP Cleaning Processes ..........eeeseeeees wee 45
Properties of Aliphatic Solvents .......... wee 47
Properties of Ketones 1.0.0... 22 cece cece cee eee teen ee eaee 49
Properties of Alcohols 2.0... . eee e cece ence eens -.. 50
Properties of Other Chlorinated Solvents .............- oe. SL
Semi-Continuous Wastewater Treatment Process ........ wee SD

Aqueous Process for Carbon Steel Chair Part .........eeeeeeeeee 82


75

CASE STUDY #:5
BIODEGRADABLE
REPLACEMENTS FOR
HALOGENATED SOL- _
VENTS AND CLEANERS .

Case Study #5 is an overview of the work
conducted since 1987 by the Air Force Engineering
and Services Center, Tyndall Air Force Base,
Florida, to determine biodegradable substitutes for
halogenated solvents and cleaners used in depot-
level maintenance operations. All of the
preliminary testing, including full-scale screening,
necessary to begin implementation of non-
halogenated solvents and cleaners for’ metal
finishing throughout the Air Force has been
compieted.

Background

Solvents and cleaners are used at the Air Force
Air Logistics Centers (ALCs) to remove wax,
grease, oil, and carbon from aircraft parts before
repairing or electroplating. Most of these solvents
are, or contain ozone-depleting agents. Many are
classified as toxic, and cannot be treated in
industrial waste treatment plant (IWTPs) that
remove organic chemicals by biological processing.
The process wastes must be shipped to approved
_ landfills for disposal.

Purpose
The purpose of this program is to:

identify halogenated solvents for removing wax,
grease, oil and burnt-on carbon that can be
replaced with biodegradable solvents; :
* identify the biodegradable solvents that can be
used: :

« develop procedures for, and implement, their
use; and -

¢ develop procedures for testing future solvents.

The program has been conducted under contract to
EG&G Idaho, Incorporated by scientists and
engineers of the Idaho National Engineering
Laboratory. The program had three phases: Phase
1 - Solvent Selection and Performance Evaluation;
Phase II - Extended Performance Testing; and
Phase III - Full Scale Testing.

Phase 1 - Solvent Selection and
Performance Evaluation

Phase { included five major tasks:

* identification of the industrial processes at the
Air Force Depot-Level maintenance
organizations in which solvents/cleaners are
used. the procedures ‘for their use, and the
processes following their use such as inspection,
electroplating. etc.:

¢ development of quality assurance methods and
procedures;

¢ identification of enhancement methods; and

* screening of solvents to evaluate the
performance of the biodegradable solvents for
(a) removing wax, oil, grease, and carbon, (b)
biodegradability, and (c) corrosiveness.

If a solvent passed the first three screening
evaluations, it was then tested for corrosiveness.
The product was required to biologically degrade
within six hours. Cleaning efficiency, equivalent to
current processing, was required. .

Phase Il - Extended Performance
Testing

Extended performance tests on solvents passing the
screening tests in Phase I, were conducted at the
field test facility at Tinker AFB, Oklahoma. Tests
included enhancement methods (effects of
temperature, mixer agitation, and ultrasonic
agitation); cleaning capacity for wax, oil, and
grease as a function of solvent loading; rinsing and
drying requirements; and impact on the biological
treatment plant at ‘Tinker AFB’s IWTP.



86

Hubbard-Hall, Inc.
P.O. Box 790
Waterbury, CT 06725
Tel: 203-754-2171

Modern Chemical Inc.
P.O. Box 368
Jacksonville, AR 72076
Tel: (S01) 988-1311
Fax: (501) 682-7691

Parker-Amchem

32100 Stephenson Highway
Madison Heights, MI 48071
Tel: (313) 583-9300

W.R. Grace & Co.

55 Hayden Avenue
Lexington. MA 02173
Tel: (617) 861-6600

Aqueous Cleaning Equipment

American Metal Wash
360 Euclid Avenue
PO. Box 265
Canonsburg, PA 15317
Tel: (412) 746-4203
Fax: (412) 746-5738

Branson Ultrasonics Corp.
41 Eagle Road

Danbury, CT 06813-1961
Tel: (203) 796-0400

Electrovert Corp.
4330 Beltway Place
Suite 350

Arlington, TX 76017
Tel: (817) 468-5171

Jensen Fabricating Engineers
P.O Box 362

East Berlin, CT 06023

Tel: (203) 828-6516

Intex Products Co.
P.O. Box 6648
Greenville, SC 29606
Tel: (803) 242-6152:

Oakite Products, Inc...

50 Valley Road

Berkeley Heights, NJ. 07922
Tel: (201) 464-6900

Qual Tech Enterprises. Inc.
1485 Bayshore Blvd.

San Francisco, CA 94124
Tel: (415) 467-7887

Fax: (415) 467-7092

3-D Inc.

2053 Plaza Drive

Benton Harbor, MI 49022
Tel: (800) 272-5326

Bowden Industries
1004 Oster Drive NW
Huntsville, AL 35816
Tel: (205) 533-3700
Fax: (205) 539-7917

Crest Ultrasonics Corp.
Scotch Rd.

Mercer County Airport
P.O. Box 7266
Trenton, NJ 08628
Tel: (609) 883-4000

Graymills
3705 N. Lincoln Ave.
Chicago, IL 60613
Tel: (312) 268-6825

J. M. Ney Company
Neytech Division
Bloomfield. CT 06002
Tel: (203) 342-2281
Fax: (203) 242-5688



54

Metals

Metals can exist either in suspension or solution.
Metals in suspension are metal chips and fines
removed from the parts being cleaned. Dissolved
Metals are metals in solution. Dissolved metals in
aqueous-based wastewater generally arise from
metals that are etched off as a result of the
alkalinity of the solution.

pH

+ A high pH, or alkaline content, can harm aquatic
life. Aqueous cleaning wastewater generated in the
metal cleaning industry is generally alkaline (i.e,
has a pH greater than 7) and in most instances. it
has a pH ranging from 9 to 12 and must be
neutralized prior to discharge.

Wastewater Minimization

Before discussing wastewater treatment options, we
discuss methods for minimizing the amount of
wastewater generated from aqueous and semi-
aqueous cleaning processes. One of the key factors
in minimizing wastewater is to optimize the
cleaning process.

Optimizing the cleaning process includes:
« Avoiding unnecessary loading

« Removing sludge promptly

© Monitoring the cleaning solution

© Maintaining equipment

© Designing more efficient Process features.

Avoid Unnecessary Loading

In addition to consuming cleaner, an excessive
amount of loading causes the soils removed from
the parts to interfere with cleaning. These solids
form scale on the heating tubes and reduce heat
transfer efficiency. Excessive loading requires
regular maintenance and increases discharge of
wastewater.

When using alkaline cleaners, alkalinity may be
Teduced by the acidity of the soils being removed,
Teaction of the alkali with the carbon dioxide in
the air used for agitation, and reaction of the
cleaner components with the hard water salts.
This reduction in alkalinity consumes the cleaner
and reduces bath life. Solutions to such problems
include using mechanical agitation, soft water,
demineralized water, or deionized water, and
frequent replacement of the used alkaline cleaner.

Remove Sludge and Soils Promptly

Removing sludge and soils promptly from cleaning
tanks will reduce cleaner use by increasing the time
before the entire tank needs to be cleaned out.

Alkaline clcaners are available that allow the
separation of excess oily soils from the cleaning
solution. These formulations use surfactants that
are good detergents but poor emulsifiers.
Agitation of the bath during cleaning keeps the
soil suspended. After a prolonged period of
inactivity, such as overnight, the oily soils float to
the surface and can be skimmed off. Although this
method is effective with mineral oil, it is less
effective with fatty oils.

Similarly there are also semi-aqueous cleaning
systems that have a hydrocarbon phase that
dissolves the soils but does not dissolve in the
water phase. When allowed to stand without
agitation, this hydrocarbon phase easily separates
out

Monitor Cleaning Solution Routinely

If solution strengths are analytically checked on a
routine basis, solution strength can be maintained
more effectively by making small and frequent
additions rather than a few large ones. Analytical
checks can be performed by the operator using
simple titration techniques (for example, the
addition of a given amount of reagent to a known
volume of cleaner and indicator can result in a
color change). Full scale titration tests may be
performed by a laboratory on a less frequent basis:
An accurate log of all tests and cleaner additions
should be kept.



50

PROPERTIES OF ALCOHOLS

Exhibit 15b

Boiling
Range °F
Methanol 6.60 0.792 147-149 54 3.5 i
H Ethanol, Prop. Anhydrous 6.65 0.799 165-176 49 1.8 |
Ethanol, Spec. Industrial Anhydrous 6.65 0.795 167-178 50 1.8 |
lsoprapanol, Anhydrous 6.55 0.786 179-182 53 1,7 |
n-Propanol 6.71 0.806 205-208 74 1.0 |
2-Butano! 6.73 0.809 207-215 72 0.9 f
| Isobutano! 6.68 0.803 225-228 85 0.6
n-Butanol 6.75 0.811 241-245 97 0.5
Amy! Alcohol (primary) 6.79 0.815, 261-282 120 03 |
|| Methy! Amy! Alcono! 672 0.808 266-271
i Cyclohexanoi 7.89 0.949 320-325
2-Ethyihexanol 360-367
Texanot

1 n-Butyl Acetate=1
2C.0.C.

Source: Southwest Chemical Company, Solvent Properties Reference Manual



12



4

Exhibit Ila
ADVANCED DESIGN DEGREASER FOR
USE WITH LOW BOILING POINT SOLVENTS
Hooded Work qransponet on openetep Degreaser
Hood
\ :
>
x
AY + Dehuriaiter Coll
f= =
= ~heatetee &
Cer or J
ac coe oer abe
= =O
: ot, BO
SSH i
Source: DuPont $16060-4

siét



Source: GAF Chemicals Corporation

Exhibit 13
NMP CLEANING PROCESSES

| SPRAY WASH CLEANING

(Spray under irnmersion recommended.)

Cleaning Tank Rinse Tanks Drying

RRS [RRS

[tmn. | [30 sec. ]
Daionized Water.
Ambient to 180° F. 120° F, 12 Psig
20 to 30 Psig.
| IMMERSION TANK CLEANING
- Cleaning Tanks Rinse Tanks Drying
4 0 TM off TM
Stow Pull ©
or Capillary
Orying.
(iinin min. (iniin:: Forced Hot
~~ Air.
—
NMP Deionized Water.
Ambient to 180° F. ' 200° F.
‘With or without Ultrasonics
© may be spray rinsed.
© stow incremental removal from Ol water.
Effective on flat surfaces.

nasi |



74

CASE STUDY #4:
PROGRAM TO
ELIMINATE WIPE
SOLVENTS CONTAINING
CFC-113

Case Study #4 is an overview of how Air Force
Plant #4, Fort Worth, Texas, developed a way to
eliminate CFC-113 use by formulating a low vapor
Pressure wipe solvent and by finding a different
technique for the disposal of wipe solvent cloths.

Currently, Volatile Organic Compound (VOC)
emissions from wipe solvent are controlled at Air
Force Plant #4 by using CFC-113 blended with
hydrocarbon solvents. CFC-113 blends reduced
wipe solvent VOC emissions by over 60 tons per
year (tpy). However, because of the CFC-113
blends, the wipe solvent operations are emitting
over 230 tpy of CFC-113.

Air Force Plant #4 is located in an ozone
nonattainment area. Air Force Plant #4 does not
want to continue to have CFC emissions from the
wipe solvent operations. Commercial low vapor
pressure wipe solvents would result in an estimated
40 tpy increase in VOC emissions.

Air Force Plant #4 is planning wipe solvent
Operations that would not increase VOC emissions
Over that currently emitted using the CFC-113
blends.

General Dynamics/Fort Worth Division developed
a plan which involves capturing a patent-pending
low vapor pressure wipe solvent before it
evaporates, Cloths are used in conjunction with
the solvent in the wipe solvent (cleaning)
operations. Most of the solvent will evapoyate
from the cloth if the cloth is left exposed to the air
for longer than 15 to 30 minutes. Placing solvent-
laden cloths in bags immediately after use in the
cleaning operation prevents solvent evaporation.

Laboratory evaluation of the bagging concept using

metallized plastic bags showed that a maximum of ~

94 percent of the solvent could be captured. When
the bagging concept was evaluated in the factory,

.

there were mixed results depending on the attitude
of the individual. A highly Tesponsible worker
could achieve about 90 percent capture, A worker
with no interest in cooperating can lower the
capture to 30 percent. Typically, the factory
evaluations resulted in a 60 to 70 percent capture,

The solvent used is a new, Proprietary, lower vapor
pressure solvent blend that has no CFCs. General
Dynamics/Fort Worth Division is seeking to patent
this blend. When other solvents are used in
conjunction with the bagging concept, the capture
rate is much lower because more solvent
evaporates from the cloth during use in the
cleaning operation.

If the bags are tied off by the end of the an eight-
hour shift and placed in the disposal cans
designated for solvent-laden cloths, then the initial
capture can be retained with less than-a one
Percent loss. The disposal cans are emptied daily,
and bagged cloths compacted directly into fibre
drums.
evaporation from the drum contents. The
compaction of the solvent-laden cloths into drums
is planned to occur within 2 days after its initial
use in the cleaning operation.

The compacted solvent-laden cloths will have
sufficient energy value to be used as supplemental
fuel in coment kilns. If the drums of compacted
cloths are not used for energy recovery, they will
be incinerated at a commercial hazardous
incinerator.

If the overall solvent capture rate exceeds 40 -

percent. the Air Force Plant #6 will achieve lower
VOC emissions than the current CFC-113 blend
wipe solvent operations. Since the new wi
solvent contains no CFC-113, most of the CFC-113
emissions will be eliminated.

A gasketed drum lid prevents solvent. -



7

Sweden, and Switzerland) have each adopted
measures to completely phaseout fully halogenated
ozone-depleting compounds. Some of the EFTA
countnes have sector-specific interim phaseout
dates for certain solvent uses. Norway and Sweden
will phaseout their use of CFC-113 in all
applications except textile dry cicaning by July 1
and January 1, 1991, respectively. Furthermore.
Austria will phaseout CFC-113 in some solvent
cleaning applications by January 1, 1992 and 1994,
Austria, Finland, Norway. and Sweden wiil all
compileteiy phaseout their usé of CFC-113 in ail
applications by January 1, 1995. Sweden also pians
an aggressive phaseout date of 1995 for MCF. ,

Cooperative Efforts

The U.S. Environmental Protection Agency (EPA)
has been working with industry to disseminate
information on technically feasible. cost effective.
and environmentaily sound alternatives for ozone-
depleting substances. As part of this effort. the
U.S. EPA is working with the Industry Cooperative
for Ozone Layer Protection (ICOLP*) to prepare
a series of manuals to provide technical infor-
mation on alternatives to CFC-113 and MCF. The
manuals are based on actual industrial experiences
that will serve as a guide to users of CFC-113 and
MCF worldwide. These manuals will be updated
periodically as technical developments occur. |

i

The first manuals in the series are:

« Conservation and Recycling Practices for CFC-
113 and Methy! Chloroform.

* Aqueous and Semi-Aqueous Alternatives to
CFC-113 and Methyl Chloroform Cleaning of
Printed Circuit Board Assemblies.

* Inert Gas Soldering/Low Residue Flux and
Paste Alternatives to CFC-113 and Methyl
Chloroform.

© Alternatives for CFC-113. and Methyl
Chloroform in Metal Cleaning.

* Appendix A presents more detailed information
about ICOLP. |

¢ Eliminating CFC-113 and Methyl Chloroform in
Precision Cleaning Operations.

+ Riveting Without CFC-113 and Methyl
Chlorotorm. :

This particular manual will take you. an individual
in an industrial organization invoived in metal
cleaning operations, through a simple structured
program to help you eliminate use of. CFC-113
and/or MCF. This manual:

* Provides you with some background on metal
cleaning:

¢ Guides you through a characterization of your
existing process:

* Outlines the criteria to consider as you develop
and select the appropmiate alternative for your
operations:

* Introduces several alternative technologies; and

+ Presents detailed case studies on actual -
industrial applications of these technologies.

The alternatives to CFC-113 and MCF for metal
cleaning discussed in the manual are:

* Aqueous cicaning
+ Semi-aqueous cicaning
« Alternative solvents.

This manuai will benefit all users of CFC-113 and
MCF in metal cleaning. Ultimately, however, the
success of your CFC-113 and MCF elimination
Strategies will depend upon how effectively you can
coordinate your reduction and elimination
programs. The development and implementation
of alternatives to CFC-113 and MCF for metal
cleaning present an exceptionally demanding
challenge for your organization. The rewards for .
success are the contribution to global
environmental protection and the increase in your
company’s industrial efficiency.



49.

Exhibit 15a
PROPERTIES OF KETONES

KETONES Formula Mol. Wt. bor se re ee exp sion Tension @
: =100 Per*F | Dynes/em
ACETONE CHCOCH, sacs | 6sa| 1s2134| 1386 | 139 | o.occeo | 237
pee ETHYL KETONE _|CH,COC,H, ze1o | 671] 174177{ 1235 | 97 | ocoove | 246
DIETHYL KETONE CHyCOC.H, e613 | 620| 212219] 435 + | o.ccccs | 268
METHYL n-PROPYL KETONE |CH,COC,H, e613 | 672| 214225] -1080 | 68 | occce2 | 252
ICYCLOHEXANONE (CH,),cO oa14 | 783] 266303] «490-| 12 | 000081 | -
. METHYL ISOBUTYL KETONE | (CH,),CHCH.COcH, | 100.16 | 668] 234244] 1205 | 47 | occa | 227
: METHYL n-BUTYL KETONE |CH,COC.H, 100.16 | 683] 237.279] -704 | 32 | o0coss | 55
em seoone (CH,)C,H,co n2a7 | 767} 237303] - | 7 | o.com |
|ACETONYL ACETONE ICH,COC.H,COCH, | 114.14 | 810] 365333] 158 - | 000082 | 396
DIISOPROPYL KETONE (CH,),CHCOCHICH,), | 114.18 | 673| 237-251] - - [- ;
METHYL nAMYL KETONE — [CH,(CH,),COCH, 11418 | 681] 297-300| 319 | 15 | occos7 | -
DIACETONE (CH),COH)\CH,CocH,| 116.16 | 782] 266356] 52 4 | c0005s | 228

Flammabie
Limite
% by Volume
in Air
In Water | O' Water Lower | Upper BONA) | sears
ACETONE CH,COCH, - ° To o | 26 {ize | 1000 | os: lox |
METHYL ETHYL KETONE _|CH,COC_H, 26.8 11.8 28 | 18 {115 | 250 0.53 191 i
DIETHYL KETONE CHyCOC,H, aa | as ss | - | - | 250 | 056 [163 |
METHYL n-PROPYL KETONE |CH,COC,H, 43 33 4s {| 16 | 82] 20 | - 180
CYCLOHEXANONE (CH.)gCO 23 ao [rs [a1] - | 100 | 049 - 4
METHYL ISOBUTYL KETONE |(CH,),CHCH,cocH, | 20 18 eo {i146 | 75 | 100 | oss ras |
METHYL n-BUTYL KETONE _{CH,COC,H, aa7F faz | 73 | 12] 80 | 100 | 055 148
Nines nomen ANONE (CH,)C,H,CO 02 3.0 we] - - 100 | 04a] e.
|ACETONYL ACETONE CH,COC,H,COCH, |e ~ 17% | - - - |: - |
ISOPROPYL KETONE (CH, ,CHCOCHICH,), -| 0.6 | : wm {- | - -{[- —
METHYL n-AMYL KETONE _ |CH,(CH,),COCH, 04 1s |r | - | - | 10 | - 149
OACETONE (CH,),C(OH)CH,COCH, | © l° a2} - - 50 | 0.50%"F | 200



iv



66

Ultrasonic Cleaning

Evaluation was conducted using a laboratory scale
ultrasonic cleaning bath with a capacity of about
two liters. Cleaners were evaluated using the same
soils and substrates described for immersion
Cleaning, but with the addition of some tubing
materials for test substrates. Cleaning time was
limited to 15 minutes. Cleaning was followed by
Spray rinsing with room temperature water.
Effectiveness was again based of broad spectrum
soils removal.

’ Results of Cleaning
Effectiveness Tests

Based on the qualitative evaluation of cleaning
effectiveness, a number of conclusions were drawn:

« Several cleaners were evaluated that were
determined to be highly effective cleaners. All
Cleaners tested showed at least some ability to
Temove general purpose lubricating oils.
However, the vigorous cleaners were Teadily
apparent by their effects on the other test soils,
ink, and silicone grease in particular. The
vigorous cleaners were then permitted to enter
the more extensive test phase of the program
described in the following sections.

© The effect of substrate on cleaning effectiveness
‘was not Strong, some indication that soils were
harder to remove from steel than from
aluminum.

¢ As expected the effect of temperature was
Significant in testing at room temperature,
degreasers that showed some effectiveness were
generally much more active when heated.
Temperature for the cleaning. Process was
limited to 140°F to prevent flash drying onto
substrate surfaces.

¢ As expected the effect of agitation was also
significant. Spray cleaning and ultrasonic
cleaning generally took half the time of low
agitation immersion cleaning.

Metallurgical Testing

Metallurgical tests were conducted to assure that
the aqueous cleaners did not cause any adverse
effects on substrate materials.

Etch Testing

Etch testing was conducted according to Boeing
Specifications. Test metals were immersed in the
cleaners at operating concentration and tempera-
ture for 24 hours. The amount of weight lost by
the test metals determined the acceptability of the
cleaners. All vigorous cleaner candidates passed
this test. Cleaners that would not. pass this test
were apparent in immersion cleaning effectiveness
testing, duc to the staining and gassing observed.

Intergranular Attack and End Grain
Pitting

Intergranular testing was carried out according to
Boeing specifications. Metal test specimens were
exposed to cleaners at operating concentration and
temperature for 30 minutes. Specimens were then
cross-sectioned to determine that intergranular
attack in excess of 0.0002 inches and end grain
pitting in excess of 0.001 inches had not occurred.
All vigorous clcaner candidates passed this test.

Sandwich Corrosion

Sandwich: corrosion testing was carried out using
Boeing specifications. Results of sandwich
corrosion tcsts indicate the corrosion that can
occur if, during the rinse cycle, the cleaners are not
adequately removed from the surface. In general,
alkaline-based cleaners were marginal to failing on
this test. The terpene-based emulsion cleaners
tested, however, did not indicate any corrosion
potential.



* Particle Removal Test. Particle removal can be
tested by artificially contaminating surfaces with
known particles of various sizes down to and
below the size of interest for removal. Precision
particles from submicron to tens of microns in
size can be obtained. Nephelometric methods
and membrane filtration methods such as
ASTM-F24 are useful low-cost techniques for
evaluating general cleaning. )

° Chemical Analysis. Surface cleanliness can be
evaluated and surface contaminants identified
and quantified by using a number of analytical
chemical techniques. The techniques most often
used are Auger electron spectroscopy (AES),
secondary ion mass spectroscopy (SIMS), x-ray
photo-electron spectroscopy (XPS). and
microscopic Fourier-Transform infrared
spectroscopy (micro FT-IR).

© Optical Monitoring and Polarized Light
Microscopy. Visual inspection using microscopy
is relatively inexpensive and gives fast results.

© End Use Tests. These tests can be conducted to
examine the effect of cleaning on subsequent
process steps such as the application of
protective coating (some of these are discussed
later in this section).

Physical and Chemical Characteristics
of the Cleaning Process

Physical and chemical characteristics include
viscosity, surface tension. density, boiling point.
freezing point, specific heat, and latent heat of
vaporization. These properties determine. the
cleaning effectiveness.

Compliance to Specifications

In instances where cleaning requirements are
governed by military or other specifications, it is
necessary to either verify compliance by
demonstrating that cleaning is adequate or
renegotiate existing specifications before switching
to alternative technologies.

Material Compatibility

In the selection of an alternative process, material

“compatibility is important. Issues to be considered

include corrosion problems and compatibility with
various process materials, such as metals, plastics.
elastomers. composites, and other sensitive
materials. 5

Compatibility problems can be evaluated by
performing a number of corrosion tests: -

Intergranular attack testing determines if the
cleaning solution unacceptably weakens the test
metal by sclectively removing material along
grain boundaries.

+ Stress corrosion (ASTM- G38) cracking (SCC)
of parts can occur when susceptible materials

* (from which the parts are made) are corrosion
sensitized during cleaning and are subsequently
aged in a tension stress application. In generat
SCC tests are run by subjecting a test specimen
of the same composition and heat treatment as
the part, to a constant tension stress Iqad after
being exposed to the corrosive medium. A
number of ASTM test methods specify complete
test details for specimen configuration and
stress loading. See TM-01-69 MACE standard
“Laboratory Corrosion Testing of Metals for the
Process Industry."

« Total immersion corrosion (ASTM 483) testing
evaluates the general corrosive attack of a
cleaner which can cause unacceptable
dimensional changes in a metal surface. A
number of specifications describe variations on
this test (MIL-C-87936, ASTM F483). Metal
cleaners for aluminum and aluminum alloys can
be evaluated in accordance with ASTM D930.
Cleaners for all other metals can be evaluated
using ASTM D1280. For example, the test can
be conducted by completely immersing. a tared
Specimen into the test solution so that there is
no air/solution interface. The specimen is ~
allowed to sit undisturbed for 24 hours after
which it is removed, rinsed, dried, and
reweighed. Corrosion is measured as weight
loss. The amount of allowable loss should be

predetermined depending on the kind of

material and use, but should be restricted to a

few milligrams.





S7

« For solutes with ionizable groups, maximum
adsorption is achieved at a pH corresponding to
the minimum ionization.

The rate of adsorption is ‘also an important
consideration. For example, while capacity is
increased with the adsorption of higher molecular
weight hydrocarbons, the rate of adsorption is
decreased. Similarly, while temperature increases
decrease capacity, they may increase the rate of
removal of solute from solution,

Carbon adsorption requires pretreatment to
Temove excess suspended solids, oil, and grease.
Suspended solids in the stream entering the carbon
adsorption bed ‘should be less than 50 parts per
million (ppm) to minimize backwash requirements.
Oil and grease should be less than 10 ppm. High
levels of oil and grease can block the pores of the
activated carbon, making it ineffective in the
adsorption of organic matter.

Activated carbon columns are typically placed in
series or parallel in wastewater treatment plants.
A minimum of two columns is generally used in
continuous operation: when the activated carbon
in one column is used up and is being regenerated,
the other column removes the contaminants. An
economical treatment. process, the major cost of
activated carbon is associated with regeneration..

PH

Aqueous cleaning wastewater is alkaline and can
_ have a pH ranging from 7 to 12, depending upon
the cleaning process, and in particular, on the type
and strength of the chemical cleaner used. Adding
sulfuric or hydrochloric acid adjusts the pH of
wastewater. The major investment cost associated
with this treatment is the cost of the mixing tank.
The operating costs, which are primarily the cost
of material, are iow. 4

Dissolved Metals :

Precipitation. The most commonly used technique
to treat dissolved metals consists of hydroxide
precipitation followed by sedimentation. Reagents
commonly used to effect the precipitation include
alkaline compounds such as lime and sodium

hydroxide. The treatment chemicais may be added
to a mix tank or directly to the sedimentation
device such as a clarifier. The major advantage of
a Clarifier is the short retention time required for
settling of the metal precipitates. However, the
cost of installing and maintaining a clarifier are
high. The siudge generated has to be disposed
according to’ Federal/state/or local regulations.

The performance of hydroxide precipitation
depends on several variables. The most important
factors affecting precipitation effectiveness are:

e Addition of sufficient excess hydroxide to drive
the precipitation reaction to completion;

* Maintenance of an alkaline pH throughout the

precipitation reaction and subsequent settling,

. Effective removal of precipitation solids.

In some instances flocculating agents are added to
enhance the sedimentation process. Hydroxide
precipitation. however, produces sludge that needs
10 be disposed of -- a fact which increases
treatment cost. :

fon-Exchange. This system uses the reversible
interchange of ions between a solid and a liquid so
that there is no permanent change in the structure
of the solid, the ion-exchange material. lon
exchange is used in a number of wastewater
treatment applications, particularly in water
softening and deionization, to remove dissolved
metals from solution. The utility of ion exchange
rests with the ability to reuse the ion-exchange
materials. Eventually the resin beds will lose their
efficiency and have to be either regenerated or
replaced, thereby producing either concentrated
wastewater or a volume of contaminated resin to
be disposed of properly. Relative energy costs for
this system are low. For exampie, in the
wastewater treatment reaction to remove lead (Pb):

2Na* R + Pb** = Pb?* R, + 2.Nat*

The exchanger R in the sodium-ion form is able to
exchange for lead and, thus, to remove lead from
the wastewater and to replace it with an equivalent
quantity of sodium. Subsequently, the lead-loaded
resin may be treated with a sodium chloride



CFC-113 AND METHYL CHLOROFORM USAGE PROFILE

A. Identification

Name of Product:

Manufacturer:

Purchase Number:

CFC or MCF Components:
Chemical Name Percent. or Concentration

L
2
3.
B. Quantification of Usage Patterns
Quantity Purchased: (specify units)

1989: : 1991:
1990: 1992:

C. CFC and MCF Disposal Practices

Annual quantity shipped out as waste
for disposal: (specify units)

Annual disposal costs:

1989 1990 1991 1992

Annual quantity shipped out for
reclamation: (specify units)

Annual cost of reclamation:

Annual quantity lost to the
environment: (specify units)

Through leakage:
Through spillage:
Through testing:

Through dragout and
evaporation:

By other means (specify)

Unaccounted for:
Source: U.S. EPA 1990



3t

Surfactants are organic compounds that provide
detergency, emuisification. and wetting in alkaline
cleaners. Surfactants are unique because of their
characteristic chemical structure. They have two
distinct structural components attached together as
a single molecule. A hydrophobic half has little
attraction for the soivent (water) and is insoluble.
The other half is hydrophilic and is polar, having
a strong attraction for the solvent (water) which
carries the molecule into solution. Their unique
chemical structure provides high affinity for surface
adsorption. Surfactants are classified as anionic.
cationic, nonionic, and zwitterionic (amphoteric).
Surfactants most useful in metal cleaning are
anionic and nonionic. . i

In spray wash alkaline cleaning virtually zero foam
can be tolerated, therefore, surfactants must be
selected that do not foam under the selected
process conditions.

Nonionic surfactant is generally the only type that
Tesuits in minimum foaming and provides good
detergency. For immersion cleaning all types of
surfactants can be used; however, in most cases the
anionic or nonionic type are used.

Process Equipment

Aqueous cleaning equipment can be characterized

as:

¢ In-line equipment-for high throughput cleaning
requirements; :

¢ Batch equipment for low throughput, such as

maintenance applications or small production

processes. :
The in-line and batch equipment can be further
subdivided into immersion, spray, and ultrasonic
equipment. Exhibit 8 presents an overview of the
advantages and disadvantages of these three types
of equipment.

Immersion equipment cleans the parts by immersing
them in a solution and using some form of
agitation to add the energy needed to displace and
float away contaminants. Soil is removed from the
metal surface by convection currents in’ the

solution,.the currents are created by heating coils
or by some mechanical action.

Spray equipment cleans parts with a solution
sprayed at medium-to-high pressure. Spray
pressure can vary from/as low as 2 psi to 400 psi or
more. In gencral. the higher the spray pressure,
the more mechanical help is provided in removing
soil from metal surfaces. Spray cleaners are
prepared with low foaming detergents which are
not as chemically effective as those used in
immersion cicaners, but are still effective because
of the mechanical agitation.

Although spray cleaning is effective on most parts,
certain configurations such as the interior of an
automobile tail pipe have soiled areas that are
inaccessible to the sprayed cleaning solution. In
these instances. immersion cleaners are more
effective.

A high pressure spray is an effective final rinse
step. Pressures may range from 100 psi in less
Critical applications to 500 psi or even 2000 psi in
critical applications. Optimization of nozzle design
such as spray pattern, drop size and formation,
pressure/velocity, and volume are very important
and have a major impact on effectiveness. A final
spray is much cleaner than an immersion bath,
since the final water touching the part can be
highly pure and filtered.

Ultrasonics equipment works well with water-based
processes. Because the cavitation efficiency is
high, the removal of particles from surfaces is
usually more effective in aqueous versus organic
solvent media. Ultrasonic cavitation efficiency is
typically less effective in CFCs and MCF than with
water-based chemistry. Process design requires
caution to insure that cavitation erosion of part
surfaces is not a problem. Certain part geometries
are also ultrasonic sensitive.

It is important to optimize your system’s
capabilities when using ultrasonic systems. Since
good ultrasonic cleaners have few standing waves,
Teflection from the surface and the walls is an
important consideration. The number of parts and
their orientation is very important for good
cleaning. The fixturing should be low mass, low
surface energy, and nonabsorbing cavitation
Tesistant material such as a stainless steel wire
frame. Avoid using plastics for fixtures because of



st
Exhibit 16
PROPERTIES OF OTHER CHLORINATED SOLVENTS

; Trichloro- Perchloro- —. Methylene.
Physical Properties CFC-113 MCF ethylene ethylene Chloride

Ozone Depleting
Potential 08 Or: 0)

Chemical Formuta CCLFCCIF, CHCl, CHCICCI,

Molecular Weight 187.38 1335 131.4
Boiling Point (*C) 72-88 86-88
Density (g/cm?) . 1.34 | 1.46

Surface Tension .
(dynevcm) : ; 25.4 29.3

Kauri Butanol Value : 130
Toxicity

OSHA PEL 8 hr.
TWA (ppm)

Flash Point (°C)

* Obtained from HSIA White Paper 1989.

Source: UNEP 1989.



oa

17

The sources of the soils must be identified. For
example. are the soils: °

+ Received as raw material?

* Produced in formingystamping operations?:
¢ Produced in general machining operations?
* Produced in sub-assembly? and/or ;

¢ Received with vendor parts?

Once the soils and their sources have been
identified, the solvent elimination process can be
optimized. For example, the type of soils can be
consolidated by reducing the number of
Processing/machining fluids and switching to water-
soluble alternatives. [t is common practice to use
a wide variety of processing fluids: in most cases
this can be avoided. Review the Material Safety
Data Sheets for all the processing fluids that are
being used and select the acceptable ones.

Try to use water-soluble and non-chlorinated.
emulsifiable machining and metal forming
lubricants. These products require smaller
quantities to perform a given task, and are more
compatible with alkaline cleaners than with
halogenated solvents and are generally emulsified
and removed from substrates at lower temperature-
concentration conditions than are neat
hydrocarbon oils. Lubricant spray applicators.
which discharge a fine, well-controlled mist. can
also decrease lubricant usage without affecting
product quality.

Other types of alternative metal forming lubricants
under development include "dry" lubricants and
thin polymer sheeting which can be peeled from
the surface after the metal forming operation.

The handling, packaging, and routing of parts
through the production process should be
Teassessed to minimize the number of times a part
is soiled and cleaned. Put particular emphasis on
consolidating, if possible, cleaning operations into
a centralized unit or location. This step improves
control of waste, emissions, and usage,

Segregation and precieaning of parts can extend
bath life and make cleaning more efficient.
Heavily soiled parts should be routed separately

through a single. precieaning system. thereby
concentrating soils in one cleaning process.

Characterize the Substrate

The sciection of the cicaning process must be
based not only on the soils being removed, but also
on the substrates being cleaned. In evaluating
alternative cleaning processes, it is important to
characterize the substrate/material being cleaned.
This includes evaluation of:

¢ The type of substrate used:

¢ The sive and geometry of the part being
cleaned:

© The porosity of the part.

Metals such as aluminum and alloys containing
Magnesium. lithium. and zinc require special
consideration because of their sensitivity to attack
by certain chemicals. For example, cleaners for
aluminum are generally mildly alkaline
(approximatcly 9-10 pH), while those for
magnesium and stecl arc best used above 11 pH.
Zinc and cadmium are subject to corrosion and
pitting by alkaline solutions.

Parts with cxcessive porosity such as coatings, parts -
that have severely rough surfaces, parts that have
permancnt overlapping joints (i.¢., rivet joints, skip
welded. and crimp joints), and parts with blind
holes and tubing‘can retain solution -- which can
cause. corrosion.



84

Shukla, S.B. 1979 (June). Role of detergent raw materials. Chemical and Petro-Chemicals Journal 20-23.
Spring, S. 1974. Industrial Cleaning. New York: Prism Press. pages 25, 150, and 188.

United Nations Environment Programme (UNEP). June 30, 1989. Electronics, Degreasing and Dry Cleaning
Solvents Technical Options Report.

U.S. Environmental Protection Agency. 1989a (December). . Technical assessment of aqueous and
hydrocarbon/surfactant based cleaning processes in the electronics, precision instruments, and metal cleaning
industries - Draft Report. Office of Toxic Substances. Washington. D.C. .

U.S. Environmental Protection Agency. 1989b (August). Waste minimization in metal parts cleaning. Office
of Solid Waste. Washington, DC.

USS. Environmental Protection Agency. 1990 (March). Manual of practices to reduce and eliminate CFC-113
use in the electronics industry. Office of Air and Radiation. EPA 4(X)/3-90.003. Washington, D.C.

Wikoff. P.M., et al. 1989 (September). Substitution of wax and grease cleaners with biodegradable solvents:
phase I. ESL-TR-89-04. Air Force Engineering and Services Center. Engineering and ‘Services Center,
Engineering and Services Laboratory.



38

HYDROCHLOROFLUORO-
CARBONS

Several HCFCs (e.g, HCFC-225ca, HCFC-225cb.
HCFC-141b, and HCFC-123) have been proposed
as possible CFC-113 and MCF substitutes. Exhibit
10 presents physical properties of these chemicals.

There are several issues to keep in mind
as you make your decision:

« HCFCs" have an ozone-depleting
potential (ODP); while the ODP is
significantly lower than CFC-113,
HCFCs are subject to production
control requirements imposed by the
Clean Air Act Amendments of 1990.
and are targeted for phaseout by 2030.

HCFCs are also subject to Section
608: National Emissions Reduction
Program that will set Lowest
Achievable Emission Levels (LAEL)
for HCFCs, Section 611: Labeling
that will require labeling of all
Products manufactured with or
containing HCFCs, and Section 612:
Safe Alternatives Policy that will
conduct overall risk characterization
and set occupational exposure limits
for the use of HCFCs.

Some HCFCs are currently available
only in limited quantities for customer
evaluation; commercial production is

expected soon.

These solvents have good cleaning
performance.

Blends of different HCFCs are also possible.
Several companies have now developed constant
boiling blends of HCFC-123 and HCFC-141b.
These solvent blends are an acceptable alternative
to CFC-113 and MCF for removing heavy grease
and water-soluble oil residues. They are equivalent

.

to CFC-113 and MCF for removing light oils, but
far less effective for buffing compounds.

If you choose blends. as an alternative to CFC-113
and MCF, it is important to consider possible
Process design changes. For example, conventional
degreasers require modification to extend
freeboards and lower condenser temperatures. In
addition. provisions such as Superheated-vapor
drying or increased dwell times in freeboard are
desirable to reduce dragout losses and can be
incorporated into the design.

The high volatility of HCFC cleaning solutions
fequire special equipment design criteria In

addition, the economic use of HCFCs may require’

special emission control features for vapor
degreasers (sce Exhibit 11a, b, and c). These
include:

* Automated work transport facilities;

* Hoods and/or automated covers on top entry:

machines;

Facilities for work handling that minimize
solvent entrapment: '

Facilities for superheated vapor drying;

+ Freeboard deepened to width ratios of 1.0 to

+ Main condenser operating at 45° to 55°F;
* Secondary condenser operating at -30° to -20°F;

* Dehumidification condenser operating at -30 to
-20°F (optional);

© Seals and gaskets of chemically compatible
materials;

¢ Stainless steel construction: -

» Welded piping containing a minimum of flanged
joints;

* A gasketed water separator or refrigerated
desiccant dryer for methanol blends;

* Accool room to work in is recommended;



79

CASE STUDY #6:
REPLACEMENT OF SOL-
VENT DEGREASING FOR
ENGINEERING PROTO- —
TYPE PARTS, PRECISION
MACHINE PARTS, AND
VARIOUS CLEANROOM
ITEMS

At Company A, CFC-113 in a number of different |
applications is being replaced. This resuits in
annual CFC-113 reductions of 136.000 Ibs. The
following are examples of some of these
operations.

Engineering Model Shop
Prototype Parts

Aqueous spray cleaning has replaced CFC-113
vapor degreasing and cold cleaning of engineering
model shop prototype parts. A glove box spray
cabinet removes water soluble. and solvent-soludie
lubricants from parts. A hand held spray wand ;
operating at 400 psi and a flow rate of 2.5 gpm

recirculates a heated (100°F) solvent-assisted

alkaline cleaner. Dilute concentrations of the

cleaner are used to reduce foaming.

Corrosion of the mild steel spray cabinet has been
eliminated by the use of a liner. Slight
discoloration of some aluminum parts has occurred
because of inadequate final rinsing.

Total equipment cost was less than $5,000. .

Annual CFC-113 savings amount to 24,000 Ibs.
($67,200 at 1990 prices).

Precision Machined Parts

Ultrasonic cleaning with a solvent assisted alkaline |

cleaner has replaced CFC-113 cold cleaning of
precision machined piece parts. Removal of

- Various

machine lubricants (water and solvent soluble)
using bench top ultrasonic cleaners at each work
station has replaced sloshing parts in CFC-113
solvent. .

The cicaner is maintained between 120° and 140°F.
Cleaning time is 10 to 30 seconds at a frequency of
.40 kHz. A deionized water rinse and air dry follow
the cleaning step. Emphasis is placed on thorough
rinsing and drying.

Total capital equipment cost for 75 bench top
ultrasonic units was $26,000.. Annual CFC-113
savings amount to 86,000 Ibs. ($240,800 at 1990"
prices). :

Cleanroom Items

CFC-113 used in wiping and rinsing applications in
cleanrooms was replaced with a volatile aqueous
Cleaner. The clcaner is a blend of high purity
water, isopropyl alcohol, ammonium hydroxide and
two surfactants. It is essentially 100 percent
volatile and leaves ultra-low cleaner residue. Items
cleaned include gloves. finger cots, and clean bench
work surfaces. Wet cleaning was necessary because
dry wiping and blow-off were determined to be
inadequate for the desired cleanliness level.

After nonvolatile residue testing, minor surface
tests, cleanroorn wipe evaluation, corrosion and
electrical contact checks all showed positive results,
this technology was implemented. However. some
Tusting of tool steel fixtures has occurred.
(Rusting is prevented with proper drying.)

The cleaner is packaged and dispensed in
precleaned spray bottles. The cleaner costs
approximately $1 per gallon for materials. Annual
CFC-113 savings from this technology amounts to
26,000 Ibs. ($72,800 at 1990 prices).



56

where “cake" builds up on the filter surface.
requiring frequent filter replacement and cleaning.

Tangential-flow prevents filter cake buildup, -

Tesulting in high filtration rates that can be
maintained continuously, eliminating the cost for
frequent membrane cleaning.

Data from aerospace industry investigators indicate
that a ceramic ultrafiltration system can be used to
recover the entire cleaner (builder and surfactant
Package) used in aqueous cleaners and that the
efficiency of oil removal is best when using
ultrafiltration. However, the ultrafiltration process
must be closely tailored for the particular aqueous
cleaner in order to prevent excessive loss of
specific components.

Coalescing. The basic principle of coalescence
involves the preferential wetting of a coalescing
medium by oil droplets that accumulate on the
medium and then rise to the surface of the
solution as they combine to form larger particles.
The important properties of the coalescing media
are its wettability for the oil and its large surface
area. Polypropylene and monofilament line are
sometimes used as coalescing media. Floating
absorption blankets or pillows are available from
a number of suppliers. The active material is
generally a blown polypropylene, which is highly
oleophilic, but will not remove active ingredients
from the cleaner.

Because of its simplicity, coalescing provides high
teliability and low capital and Operating cost. It
cannot be used, however, to remove emulsified
-oils, if they are present, they must be pretreated
before being sent to the coalescing unit.

Chemical Treatment. Chemical treatment is often
used to breakdown stable oil-water emulsions.
Chemical treatment consists of three steps: (1)

coagulation -- breaking of the ‘emulsion, (2) °

flocculation -- agglomeration of the tiny ‘oil
droplets to form larger droplets, and (3)
sedimentation — the removal of oil from water.

Chemicals ( ¢.g., polymers, alum. ferric chloride,
and organic emulsion breakers) break emulsions by
neutralizing repulsive charges between Particles,
Precipitating or salting out emulsifying agents, or
altering the interfacial film between the oil and
water. After the addition of the coagulant, another
chemical, called the flocculent. is added to

aggiomerate the tiny oil droplets into larger oil
drops so that they can be easily separated. Typical
floccuients are high molecular weight polymers.

‘The disadvantage of this process is that chemical
treatments used to break the emulsions generate
Sludge that has to be disposed of. This
Tequirement increases cost, particularly if the Icvel
of emulsified oil needs special chemical treatment.

Organics

Organics present in the wastewater from aqueous
and semi-aqueous based processes are generated
from contaminants like the hydrocarbon chemicals
and surfactants used in the chemical cleaners and
finishing and pigment compounds used in the

Processing of the metal parts in the metal industry. .-

Although oil and grease are organic in nature, they
are not considered organic pollutants under this
definition. It is known that many. organic

compounds arc eliminated during the treatment °

steps for the removal of waste oil and grease.
High molecular weight organics are much more
soluble in oil than in the water and are skimmed
off with the removed oil.

Carbon adsorption. This system involves passing
the wastewater through a chamber containing
activated carbon to remove the dissolved organic
from the wastewater. Carbon adsorption is one of
the most efficient organic removal Processes
available. In addition, it is reversible, thus
allowing activated carbon to be regenerated by the
application of heat and steam and then reused,

Some general rules relating to carbon adsorption
capacity are:

¢ Higher surface area gives a greater adsorption *

capacity;

“© Larger pore size gives a greater adsorption

capacity;

« Adsorptivity increases as the solubility of the
solute decreases. For hydrocarbons, adsorption
increases with molecular weight;

¢ Adsorption capacity decreases with increasing
temperature; :



80

. CASE STUDY #7: PRO-
GRAM TO ELIMINATE
METHYL CHLOROFORM
USE IN STEEL CHAIR
MANUFACTURING
OPERATIONS

Case Study #7 is an overview of how LA-Z-BOY,
Monroe, Michigan, a ‘large manufacturer of
furniture, converted a methyl chloroform vapor
degreasing process to a semi-aqueous based
process, The company previously had used methyl
chloroform to clean oil and metal fines from
stamped carbon steel chair parts prior to painting.
LA-Z-BOY decided to switch to a semi-aqueous
based process using Bio T Max (a citrus terpene
based cleaning agent). LA-Z-BOY is satisfied with
the new semi-aqueous based cleaning process and
has found considerable improvement in paint
adhesion compared to their old system.

Process Description

Installing the Bio T cleaning process involved
modifying the existing vapor degreaser tank so that
it could be used as a dip tank for the wash stage.
The capacity of this tank is 1,558 gallons. The
Tinse tank used for the semi-aqueous process is an
old wash tank that had been previously utilized in
the facility. The rinse tank has a capacity of 1,100
gallons. Both the wash and rinse tanks were fitted
with spray nozzles and 95 gpm feed pumps to
recirculate the water.

The wash and rinse stages are operated at room
temperature using DI water as the cleaning
medium. The concentration of Bio T in the wash
tank is maintained at 8-10 percent concentration.

Parts to be cleaned are placed on hooks on a
monorail, and undergo the following sequence of
steps (see Exhibit 18):

* Parts are processed through the wash and rinse
Stages. The wash and rinse cycles last about 5-
10 minutes depending on the level of soil
loading and the throughput required. The time
in the wash and rinse tanks is set by adjusting
the speed of the monorail.

¢ Next, the parts are painted by processing them
through a water based paint tank and a. paint
rinse tank. Parts are painted using an electro-
deposition process using water based paints.
The. paint process is the same as that used with
the old vapor degreasing process.

« After painting, the parts are passed through a
dryer. The dryer is also the same as that used
with the old vapor degreasing process.

« After the parts exit the dryer, they are unloaded
and new parts are loaded onto the monorail.
The loaded parts then enter the wash stage and
repeat the above sequence of steps.

The semi-aqueous system is set up so that the’
permeate from the rinse tank that contains the
carry over of Bio T from the wash tank is fed back
to the wash tank. Both tanks are made up with DI
water to maintain the tank water level. This is .
necessary to make up for water loss due to drag
out and evaporation.

The semi-aqueous cleaning system is equipped with
an on-line filter used to remove residue metal fines
and chips, and an oil absorbent filters used to
remove free floating oil. It has been noted that
during the night when the system is shut down, oil
separates and floats to the top. This oil is
skimmed off before the unit is turned on in the
mornings.

Capital and Operating Costs
LA-Z-BOY estimates: that the capital costs
associated with this process is $8,211. This is
based on costs for:

© Two sock type filtering systems (100 gpm);

* Two bottom feed pumps (3,450 rpm, 95 gpm);

* Sandblasting and painting of rinse tank, |



ae REVIEW OF EXISTING PROGRAM

Following the recommendations presented so far for developing a non-CFC-113 and MCF
cleaning program. the following sequence of activities should be performed/cartied out next:

Determine where and why CFC-113 and methyl chloroform are consumed in
metal cleaning operations: oa

Characterize existing cleaning processes. This activity will help you understand
how metal cleaning integrates with other manufacturing processes and determine
whether cleaning is necessary: .

Characterize the soils and their sources. Identify the type of soils being removed
and the steps to be taken to reduce the soiling of parts;

Characterize the substrate materials being cleaned. This step will assist in
identifying the type, shape, and geometry of materials being cleaned;

Establish criteria for selecting an alternative cleaning process. These criteria
include organizational, technical. environmental, health, and safety issues that
must be considered before selecting an alternative process. .

The benefits resulting from these steps include a better understanding of cleaning needs,
elimination and consolidation of certain cleaning operations, and development of a
systematic procedure for selecting an alternative cleaning process. With this understanding,
the next section describes some major alternative processes to solvent based cleaning.



FOREWORD oS

The 1987 Montreal Protocol on Substances that
Deplete the Ozone Layer, and subsequent 1990
amendments and adjustments, restricts the produc-
tion and consumption of ozone-depleting chemi-
cals. Two such chemicals. chlorofluorocarbon
1,1.2-trichloro-1.2.2-trifluoroethane — (commoniy
referred to as CFC-113) and 1,1.1-trichloroethane
(commonly referred to as methyl chloroform or
MCF), will be completely phased out in developed
countries by years 2000 and 2005 respectiveiy, and
ten years later in developing countries. j

Exhibit | lists the countries that are Parties to the
Montreal Protocol as of April 1991. In addition.
many companies worldwide have corporate policies
to expedite the phaseout of ozone depleting
chemicals. Exhibit 2 presents the corporate
policies on CFC-113 reduction for some of these
companies.

In addition to providing regulatory schedules for
the phaseout of ozone-depleting chemicals, the
Montreal Protocol established a fund that will
finance the incremental costs of phasing out
ozone-depleting substances by developing countries
that are Party to the Protocol. \

U.S. Clean Air Act
Amendments

The U.S. Clean Air Act (CAA) was amended in
1990, and contains several provisions pertaining to
stratospheric ozone protection. Section 602 of the
CAA presents a list of ozone-depleting substances
that are restricted under the CAA. These ozone-
depleting substances are defined as Class I and
Class II substances. Class [ substances include all
fully halogenated chlorofluorocarbons (CFCs)
including CFC-113, three halons. MCF, and carbon
tetrachloride. Class IT substances are defined to
include 33 hydrochlorofluorocarbons (HCFCs).
The sections of the CAA that are of importance to
users of this manual are discussed below.

Exhibit 1

MONTREAL PROTOCOL PARTICIPANTS
Argenuna Malawi
Austratia, Malaysia
Ausina Maldives
Bahrain Malta
Bangtadesh Mexico
Belgium Netherlands
Brazt New Zealand
Bulgaria, Nigena
Burkina Faso. Norway ©
Cameroon Panama
Canada Poland
Chile Portugal
Czechoslovakia Singapore
Denmark South Africa
Ecuador Spain
Egypt Sri Lanka
European Sweden
Community Switzerland
Finland Syrian Arab Rep.
Fiji Thailand
France The Gambia
Germany Trinidad and
Ghana Tobago
Greece Tunisia
Guatemata Uganda
Hungary USSR (includes
Iceland Byelorussia and
Iran Ukraine)
Ireland United Arab
Ttaty Emirates
Japan * United Kingdom
Jordan United States
Kenya Uruguay
Libya Venezuela
Liechtenstein Yugoslavia
Luxembourg Zambia

Non-Ratifying Signatones: Congo, Indonesia,
Israel, Morocco. Philippines. Senegal, Togo

Date: April, 1991



PHYSICAL PROPERTIES OF HCFCs -
AND OTHER SOLVENT BLENDS

CFC-113

HCFC-225ca HCFC-22Sceb

HCFC-141b/'
HCFC-123/
Methanot

Chemical Formula = CCLFCCIF,

Ozone Depleting
Potermal

Boiling Point (°C)

Viscosny (cps)
@2"c

‘Surface Tension
(dyne/em)

Kauri-Butanol
Value

Flash Point *C
Toxicity

' Several other HCFC-141b/HCFC-123 blenas exist.
123 (60 W.%/20 wt.%) for straight otls and an azeotro}

oils,

CF,CF,CHCL ——-CCIF,CF,CHCIF

None

Underway | Underway

Near Completion

Chemical manufacturers recommend.a blend of HCFC-141b/HCFC-
pe ot HCFC-141 b/HCFC-123/metnanol tor sem+-synthetic and synthetic





34

SEMI-AQUEOUS
CLEANING

Hydrocarbon/surfactant cleaners are emulsion
cleaners that can be substitutes for CFC-113 and
MCFin meal cleaning applications. Hydrocarbon/
Surfactants have been included in many different
cleaners formulated for different purposes. Hydro-
carbon/surfactants are used in cleaning processes in
two ways. They are either emulsified in water
solutions and applied in a manner similar to
Standard aqueous cleaners or they are applied in
concentrated form and then rinsed with water.
Because both methods use water in the cleaning
Process, the hydrocarbon/ surfactant based process
is commonty known as a semi-aqueous process (see
Exhibit 9).

Advantages

The advantages of semi-aqueous cleaning soiutions
include the following:

¢ Good cleaning ability especially for heavy
grease, tar, waxes, and hard to remove soils;

© Compatible with most metals and plastics;

© Suppressed vapor pressure (especially if used in
emulsified form);

¢ Non-alkalinity of process prevents etching of

metals thus helping to keep metals out of the
waste streams:

¢ Reduced evaporative loss;
+ Potential decrease in solvent purchase cost;

¢ A rust inhibitor can be included in the
formulation to protect pans from Tusting.

Disadvantages
The disadvantages include:

¢ Rinsability problems, because residues can be
left;

+ Recycling or disposal cost of wastewater could
make the process less economically viable;

* Flammability concerns if a concentrated cleaner
is used in spray cleaners. However, the *
flammability issue can be solved with proper
equipment design; °

* Some cleaners have objectionable odors;
* Some of the cleaners are VOCs; |

¢ Drying equipment may be Tequired in some
applications; and

+ Some cleaners can auto-oxidize. For example,
d-limonene (a type of terpene) can auto-oxidize
from contact with air. This can be reduced
using an antioxidant additive.

Cleaning Process

The steps in a typical Semi-aqueous cleaning
Process are analogous. to aqueous applications.
Equipment for use with semi-aqueous processes is
also similar to aqueous cleaning equipment
designs.

The four major steps used in the cleaning

Wash step: with a hydrocarbon/ . |}
surfactant;

Rinse step with water;

Drying process .to remove excess
water,

Wastewater disposal.



12

EXISTING CLEANING PROCESS

CHARACTERIZATION

To develop an effective program to reduce and
eliminate the use of CFC-113 and MCF, you must
first acquire a good knowledge of your plant
operations. The types of questions you should be
able to answer include the following:

What materials/substrates arc you
cleaning?

Where are the contaminants coming
from?

What types of contaminants are you
removing?

Why are you performing metal
cleaning at your plant?

Is this cleaning step necessary?
What are the effects of metal cleaning

on the upstream and downstream
aspects of your process?

What processes are using CFC-113
and MCF?

Where do CFC-113 and MCF
emission losses take place?

Who purchases CFC-113 and MCF?

Who accepts delivery of CFC-113 and
MCF?

How are CFC-113 and MCF handled
from arrival to ultimate use?

Characterize Solvent Use

The first step in addressing the use of CFC-113
and MCF is to designate a team to coordinate the
solvent reduction and elimination programs. Team
members should represent various plant functions

.’ including process design, production and
~ production engincering. environmental control,

occupational health and safety, quality control, and
purchasing. The tcam Icader of the reduction and
elimination programs should conduct a survey to-
determine the quantities of CFC-113 and MCF
used in every aspect of the plant’s operations. An
example survey form that could be used for this
purpose is shown in Exhibit 4. Material Safety
Data Sheets are useful in identifying the
composition. of solvents.

The total quantity of CFC-113 and MCF
used in your processing should be divided
by the appropriate production unit for
your operations to obtain the ratio of -

kilograms or pounds of CFC-113 and
MCF used per production unit. This
value will be your benchmark for
reduction and elimination programs.

Determine if Solvent
Cleaning Is Necessary

After identifying the processes where solvents are *
being used. ihe next step is to determine whether
each cleaning step is necessary. The entire
production system should be viewed with a focus
on improved procedures, housekeeping, and
process changes to eliminate soiling of parts.





Table of Contents

List of Exhibits ©0000... 0. cece ccc ce cece nee e eee eee eeeeeeeeens vii
Foreword . 2.0... 26 cece cece eee cece reece reese eeeteeeeeneee 1

USS. Clean Air Act Amendments ........ 000. e eee e cece ee eecceeences

Excise Tax... 2... eee cece e eee eee

Other International Phaseout Schedules ...

Cooperative Efforts ........ 6c eee e cece eet ec eee te ence eeeeaees
Structure of the Manual .............00. 2.002.000 ce eee “eee e ete e eee eee eee 9
Introduction to Metal Cleaning ........ awe eben ee Woeee eens Lees IL
Existing Cleaning Process Characterization ............. ee ceeeeeceeeeese +e 13

Characterize Solvent Use ...... 0... ccc sec e eee eee e eee e nee eneeeee 1B

Determine if Solvent Cleaning is Necessary ... 13

Characterize the Soils and their Sources .... wee 1S

Characterize.the Substrate 2.00... eee eee cece eee ee nes 17
Alternative Method Overview ..................000005 Lene eee e ee eeee - 19

Organizational

Technical .....

Economic ......... eee e eee e eee eeee

Alternative Materials and Processes .........0..- ec ceecceeceeeeeeeeecees 127

Aqueous Cleaning .........0 2.0.02 ee eee e eee pce eee daceeeeeeees
‘Semi-Aqueous Cleaning . .
Hydrochiorofluorocarbons
N-Methyl-2-Pyrrolidone ....
Aliphatic Hydrocarbons . . .
Miscellaneous Solvents ......2 2.0.00 eee e eee eect eee eee e ee enee



CASE STUDIES OF INDUSTRIAL PRACTICES

The following section presents case studies of alternative technologies.
Mention of any company or product in this document is for informational purposes onlyand
does not constitute a recommendation, either express or implied. of any such company or

product by EPA, ICOLP, ICOLP committee memibers. and the companies that employ the’
ICOLP committee members.

The case studies presented include:

* Case Study #1: Evaluation of Aqueous Cleaning tor Aluminum and Ferrous
Alloys

Case Study #2: Selection of Aqueous Process for Cleaning Components for
Solenoid Valves :

Case Study #3: A Five Phase Program for Developing Alternative Cleaning
Case Study #4: Program to Eliminate Wipe Solvents Containing CFC-113

Case Study #5: Biodegradable Replacements for Halogenated Solvents and
Cleaners

Case Study #6: Replacement of Solvent Degreasing for Engineering Prototype
Parts, Precision Machine Parts, and Various Cleanroom Items

Case Study #7: Program to Eliminate Methyl Chloroform Use in Steel Chair
Manufacturing Operations : :



18 a7



Exhibit 3

| PHASEOUT DATES FOR CFC-113 AND METHYL CHLOROFORM
UNDER THE U.S. CLEAN AIR ACT -
AND THE MONTREAL PROTOCOL

FC PHASEOUT

Montreal Protocol

Clean Air Act

Reduce from 1986 Freeze at 1986 production and consumption levels by July

levels by: 2 1989 :
1991- 15% * 20% reduction from 1986 levels by January 1993
1992 - 20% sO 50% reduction from 1986 leveis by January 1995
1993 - 25% . 85% reduction trom 1986 levels by January 1997
1994 - 35% 100% reduction trom 1986 levels by January 2000
1995-50% + |
1996 - 60% Also call for future assessment to determine if an earlier
1997 - 85% complete phaseout by January 1997 is achievable
1998 - 85%
1999 - 85%
2000 - 100%

METMYL CHLOROFORM PHASEOUT
Clean Air Act

Freeze at 1989 levels Freeze at 1989 production and consumption levels by
by 1991 January 1993

Freeze at 1989 levels 30% reduction from 1989 levels by January 1995
continues in 1992 70% reduction from 1989 levels by January 2000
Reduce from 1989 100% reduction from 1989 levels by January 2005
levels by: .

1993 - 10%
1994 - 15%
1995 - 30%
1996 - 50%
1997 - 50%
1998 - 50%
1999 - 50%
2000 - 80%
2001 - 80%
2002 - 2004*
2005 - 100%

Montreal Protocol

* New authority would be given to EPA to authorize, to the extent consistent with the Protocol. the
production of methyl chloroform in an amount not to exceed 10% of baseline per year in 2002, 2003,
and 2004 for use in essential applications for which no safe substitutes are available. .



23

new process might require rearranging subsequent
Processes to optimize the floor pian. In ‘some

cases. alternatives take up more space than solvent —

cleaning processes. For example, most aqueous
cleaning processes include a drying stage that
requires additional floor’ space. Rearranging
existing equipment or installing a new process also
may trigger permitting requirements.

Operating and Maintenance
Requirements

Each new process will require operating and
maintenance procedures. The new process might
be more cumbersome to operate and may require
special operator training. j
Maintenance of process equipment on a regular
basis is critical. For example, cicaning of spray
nozzies is necessary to remove soil contamination
that would make them less effective. Pumps and
valves should also be checked reguiariy.

Economic

Process economics is a key factor in the selection
of alternative processes. Initial costs associated
with an alternative process include capital costs of
equipment. possible costs associated with waste
treatmenvhandling equipment and costs for permit
changes for new construction or new Operating
"procedures. In addition, operating cost equations
include material, labor. maintenance. and utility
costs. Cost estimates for an alternative process can
be developed through preliminary process design.

One simple approach is to calculate net present
value (NPV) based on the discount rate and period
of investment your company uses. The NPV is
calculated as follows, where (n) is the number of
years, and (i) is the discount rate. .

NPV = Cost, + Costy/(1+i) +

Costy/(1+i)? + ... + Costy/(1+i)*

While traditional economic considerations such as
Tate of return and payback period are important.
the CFC-113 and MCF reduction program can be
justificd on a basis of environmental protection
and solvent supply reliability. An important
component of the analysis should recognize that
the price of CFC-113 and MCF will increase
Tapidiy as supplies are reduced and then eliminated
and taxes are imposed. Because of the
considerable difference in ozone-depleting
Potential. the price increases of CFC-113 and MCF
will vary. Include the cost savings resulting from
Savings in solvent consumption. Some new
alternative processes are much less expensive than
the current CFC and MCF processes being used.

Environmental, Heaith, and
Safety

Important considerations include:

* Compatibility with appropriate federal, state, and
local regulations. State and local reguiations on
ozone-depleting chemicals, VOCs, effluents of
waste can be more stringent than their federai
counterparts. For example, some cities have
taken sicps to phase out ozone-depleting
compounds (ODCs) more quickly than the U.S.
Clean Air Act requires. In addition, to the .
phaseout requirements under the Clean Air Act
there are a number of provisions that will go
into effect over the next few years that will also
impact the selection of alternatives. These
provisions include Section 608: National
Emissions Reduction Program, Section 611:
Labeling, and Section 612: Safe Alternatives
Policy. These and other provisions must be
considered before selecting alternatives.

© Compatibility with regulatory trends. Since new
environmental policy is emphasizing pollution
prevention and risk reduction, it is prudent to
Move to cleaner products and processes that are
less polluting, less energy-intensive, and less
dependent on raw materials.

° Public perceptions. Recent legislation, such as
“right-to-know* laws has provided the public
with more information about the chemicals used
by specific plants and their associated risks.



92



List of Vendors for CFC-113 and Methyl Chloroform

Alternative Solvents

Allied-Signal
PO Box 1139 R
Morristown, NJ 07960
Tel: (201) 455-4848
Fax: (201) 455-2745

Dow Chemical
2020 Dow Center
Midland, MI 48674
Tel: (517) 636-8325

Daikin Industries, Ltd.
Chemical Division

1-1 Nishi Hitotsuya
Settsu-Shi, Osaka 566
Japan

Tel: 81-6-349-5331

GAF Chemicals Corporation
1361 Alps Rd.

» Wayne, NJ 07470.
Tel: (201) 628-3847

Aqueous Cleaners

Ardrox

16961 Knott Avenue
La Mirada, CA 90638
Tel: (714) 739-2821

DuBois Chemicals, Inc.
511 Walnut Street
Cincingati, OH 45202
Tel: (513) 762-6839

* ‘This is not an exhaustive list of vendors. For more names check the Thomas Register. Vendors can be
cited in subsequent editions of this document by sending information to |COLP. ICOLP’s address is provided
in Appendix A. Listing is for information purposes only, and does not constitute any vendor endorsement by

Solvent Cleaning Substitutes*

Arco Chemical Company
3801 West Chester Pike
Newton Square, PA 19073

Exxon Chemical Company
P.O. Box 3272

Houston, TX 77001

Tel: (800) 231-6633

DuPont Chemicals
Customer Service
B-15305

Wilmington. DE 19898
Tel: 1-800-441-9450

ICI Americas Inc.

P.O, Box 751
Wilmington. DE 19897
Tel: (302) 836-4469

Brulin

2920 Dr. Andrew J. Brown. Ave.
PO Box 270

Indianapolis, IN 46206

Tel: (317) 923-3211

Freemont Industries, Inc.
Valley Industrial Park
Shakopee, MN 55379
Tel: (612) 445-4121

EPA or ICOLP, either express or implied, of any product or service offered by such entity.



s

manufactured with Class [ substances from the
labeling requirement based on the lack of
substitutes, the products must be labeled by
January 1, 2015; and

« No later than’ January 1, 2015. products
containing or manufactured with a Class II
substance must be labeled. EPA may require
such products to be labeled as early as May 15,
1993 if it determines. after notice and
opportunity for public comment, that there are
Substitute products or manufacturing. process
available,

The CAA allows for petitions to be submitted to
EPA to apply the requirements of Section 611 to
products containing Class II substances or a
product manufactured with Class [ or II substances
which are not otherwise subject to the
Tequirements. This petition process will operate
between May 15, 1993 and January 1. 2015. For
products manufactured with Class I substances. a
successful petition would result in the labeling of
a product previously determined by EPA to be
exempt. For products containing or manufactured
with Class II substances. the petition process could
lead to labeling of a product that had been left
unlabeled by default.

Section 612: Safe Alternatives Policy

‘Section 612 establishes a framework for evaluating
the environmental impact of current and future
“ potential alternatives. Such regulation ensures
that the substitutes for ozone-depleting substances
will not create environmental probiems themselves.
‘The key provisions of Section 612 require EPA to:

@ Issue rules by November 15, 1992 which make
it unlawful to replace any Class [ and Class II
substances with a substitute that may present
adverse effects to human health and the
environment where EPA has’ identified an
available or potentially avaifable alternative that
reduces the overall risk to human health and
the environment.

a Publish a list of prohibited substitutes,
organized by use sector, and a list of the
corresponding alternatives:

= Accept petitions to add or delete a substance
previously listed as a prohibited substitute or an
acceptable alternative:

= Require any company which produces a
chemical substitute for a Class [ substance to
notify EPA 90 days before any new or existing
chemical is introduced into commerce as a
significant new use of that chemical. In
addition. EPA must be provided with the
unpublished health and safety Studiesidata on
the substitute.

To implement Scction 612 EPA will (1) conduct
environmental risk characterizations for substitutes
in each enc use and (2) establish the Significant
New Alternatives Program (SNAP) to evaluate the
future introduction of substitutes for Class I
substances. EPA has aiso initiated discussions with
NIOSH. OSHA. and other governmental and
nongovernmental associations to develop a

‘consensus process for establishing occupational

exposure limits for the most significant substitute
chemicals.

The environmental risk characterizations for the
Substitutes will involve a comprehensive analysis
based on the following criteria: ozone-depleting
potential, flammability, toxicity, exposure effects,
energy efficiency, degradation impacts, air, water,
and solid waste/hazardous waste pollution effects,
and global warming potential. Economic factors
will also be considered. EPA will organize these _
assessments) by use sector (i.e. solvents,
refrigeration. cic). The risk characterizations will
result in risk-management strategies for each
Sector and substitute. EPA will then categorize a
substance as - unacceptable. acceptable with
limitations on use or quantity, acceptable without
comment, or delayed pending further study.
Petitions will be allowed to change a substance’s
Status with the burden of proof on the petitioner.

The SNAP program. effective November 15, 1992,
will review future substitutes not covered in the
initial risk characterization process. SNAP will ©
evaluate a substitute based on the criteria
established for the risk characterization and will
classify it simnilarty.



2)

Solvent -- Although not a strictly correct definition, in this context a product (aqueous or organic) designed
to clean a component or assembly by dissolving the contaminants present on its surface.

Surfactant - A product designed to reduce the surface tension of water. Also referred to as tensio-active
agents/tensides. Detergents are made up principally from surfactants.

Terpene — Any of many homocyclic hydrocarbons with the empirical formula CroH¢, characteristic odor.
Turpentine is mainly a mixture of terpenes. See hydrocarbon/surfactant blends.

Volatile organic compound (VOC) -- These are constituents that will evaporate at their temperature of use
and which, by a photochemical reaction, will cause atmospheric oxygen to be converted into potential smog-
promoting tropospheric ozone under favorable climatic conditions.





59

Exhibit 17

SEMI-CONTINUOUS WASTEWATER
TREATMENT PROCESS

Wastewater ;
Holding !

Tank

inced z
Enka Carbon lon Removal of

Ultra-
Gravity rs a ow Qe _
Separator Filtration Adsorption Exchange Dissolved Matats

Removal of Removai of Removat of
Free Olt & '- Publics
Dissoived- Organics Municipal
Suspended Solids Emulsitied Oi PH Adjusting Waste
Tank Treatmont
. : Facility

Reuse as
Process Water

Source: EPA 1989a : , fst3ts



65

CASE STUDY #1:
EVALUATION OF
AQUEOUS CLEANING .
FOR ALUMINUM AND
FERROUS ALLOYS

Case Study #1 is an overview of the work
conducted by Boeing since mid-1987 to evaluate
aqueous cleaners and the aqueous cleaning process.
The current status of the program encompasses the
use of aqueous cleaning for aluminum and ferrous
alloys. Work on titanium and magnesium alloys,
although virtually complete, is still in progress.

Selection of Cleaners for
Evaluation

An initial list of 10 cleaners was developed from

vendor listings available through the literature. by .

selecting companies recognized as Boeing suppliers
in other product areas. Selection criteria of the
cleaners for evaluation include indicated cleaning
effectiveness, low toxicity materials, and
Tegeneration capability. As the project progressed,
more contacts were made both within the
aerospace industry and with other chemical
suppliers. These contacts Icd to the eventual
evaluation of 48 aqueous cleaner formutations, all
meeting the initial selection criteria.

Cleaning Effectiveness
Testing

The evaluation of aqueous cleaners began with the
specification of the soil to be removed and the
determination of cleaning performance. Most
industrial specifications require only that a cleaner
“leave no visible residue." Two specifications were
found that detail test soils to be removed (SAE
AMS 1536 and 1537) and the amount of soil
removal required, as measured by weight. Cleaners
for the evaluation were expected. to remove all
visible soils,.so the measurement of soils removed

by weight was not applicable. In addition, vapor
degréasers at Boeing arc often general cleaning
Operations that must remove a variety of soils from
a number pf substrate materials. For these
Teasons, no particular standard cleaning
Specification appeared applicable.

Immersion Cleaning —

Immersion cicaning effectiveness tests. were
conducted on aluminum, steel, and titanium test
Panels using as test soils "permanent" marking ink,
general purpose lubricating grease, silicone grease,
general purpose lubricating oils, rust preventive
compound. tar. lipstick (not a shop soil but a
highly visible hydrocarbon mixture), solder flux,
and machining wax. Cleaners were made up in
bench-scale quantitics (2 liters), and generally
Operated at two concentrations and over a temper-
ature range based on suppliers’ recommendations.
Agitation was limited to that necessary for
temperature control. Immersion time was set at 20
minutes with qualitative evaluation of the cleaning
effects performed every five minutes. Cleaning was
followed by immersion rinsing in warm water.

Degreasers were described as vigorous if a
particular soil was completely removed within 10
minutes. Other terms were used to describe
removal or visible effect on soils at particular time
intervais. Aftcr the compiction of testing, cleaners
that indicated an ability to quickly remove a broad
spectrum of'soils were judged as "most effective."
This judgment was made recognizing that, for a
specific cleaning operation, degreasers that ranked

. lower in overall effectiveness may be appropriate

choices for the removal of particular soils.

Spray Cleaning

A single-nozzie spray tank was constructed for the
evaluation of spray.cleaners. Cleaners were
evaluated using the same soils and substrates
described for immersion cleaning. However,
cleaning time was limited to 15 minutes and some
evaluations were conducted at five seconds interval
for light hydrocarbon oils. Cleaning was followed
by spray rinsing with room temperature water.
Effectiveness was again based on broad spectrum
soils removal.





APPENDIX A

INDUSTRY COOPERATIVE _
FOR OZONE LAYER PROTECTION

The Industry Cooperative for Ozone Layer
Protection (ICOLP) was formed by a group of
industries to protect the ozone layer. The primary
tole of ICOLP is to coordinate the exchange of
- Non-proprietary information on alternative
technologies, substances, and processes to
eliminate ozone-depleting solvents. By working
closely with solvent users, suppliers. and other
interested organizations worldwide, ICOLP seeks
the widest and most effective dissemination of
information harnessed through its member
companies and other sources. :

ICOLP corporate members include:

AT&T

Boeing Company

British Aerospace

Compaq Computer Corporation
Digital Equipment Corporation
Ford Motor Company

General Electric

Hitachi Limited

Matsushita Electric Industrial
Company

Mitsubishi Electric Corporation

Motorola

Northern Telecom

Sundstrand

Texas Instruments

Toshiba Corporation

In addition, ICOLP has a number of industry
association and government organization affiliates.
Industry association affiliates include American

Electronics Association (AEA), Electronics
Industries Association, Japan Electrical

- Manufacturers Association and Halogenated

Solvents Industry Alliance (U.S.). Government
organization affiliates include the City of Irvine,
California. the State Institute of Applied Chemistry
(U.S.S.R.), the Swedish National Environmental
Protection Agency, the ‘U.S. Air Force, and the
U.S. Environmental Protection Agency (EPA).
The American Electronics Association, the
Electronic Industries Association, the City of
Irvine. California, the Japan Electrical

. Manufacturers Association, the Swedish National

Environmental Protection Agency, the U.S. EPA,
the U.S. Air Force, and the U.S.S.R. State Institute
of Applied Chemistry have signed formal
Memorandums of Understanding with ICOLP.
ICOLP will work with the U.S. EPA to
disseminate information on technically feasible,
cost effective, and environmentally sound
alternatives for ozone depleting solvents.

ICOLP is also working with the National Academy
of Engineering to hold a series of workshops to
identify promising research directions and to make
Most efficient use of research funding. ~

The goals of [COLP are to:

» Encourage the prompt adoption of safe,
environmentally acceptable, nonproprietary
alternative substances, processes, and
technologies to replace current ozone-depleting _
solvents;

» Act as an international clearinghouse for
information on alternatives;

¢ Work with existing private, national, and
international trade groups, organizations, and



1s

A suggested hierarchy of options is:
Reduce or eliminate soiling of parts:

¢ Improve housekeeping;

¢ Consolidate operations.

For example, in a number of metal finishing
Processes, solvent cleaning is followed by alkaline
cleaning. The question to ask is whether alkaline
cleaning can handle the soil loading if the solvent
Cleaning step is eliminated. The answer may be yes.
Or, if chip removal is desired. can a mechanical
means (such as air blow-off, water Sprayiflush)
replace solvent cleaning?

Another useful step is to evaluate the processes’
where solvent is being used. and dciermine
whether alternative materials would make soivent
cleaning unnecessary. Exhibit 5 presents methods
that could be considered. For example. if the
Process before the solvent cleaning step was
changed as suggested in Exhibit 5, could the
solvent cleaning step be eliminated? If the answer
is no, it will be necessary to find alternative solvent
cleaning methods. These alternatives are discussed
later.

Characterize the Soils and
Their Sources

A critical part of the initial stage of process
evaluation is characterizing the soils and their
sources. This study of existing materials and
procedures will help identify means of eliminating
the need for cleaning or reducing the amount of
soil to be removed.

Conduct a factory survey to characterize the soils
and identify their sources. This survey should
include visits to each production process,
observation of existing procedures, interviews with
operators of the equipment, and collection of soil
samples for preliminary laboratory tests. This
process will provide firsthand experience and aiso
establish contact and develop rapport with the
individuals who will ultimately be effected by the
process change. Their cooperation and input are
essential to the success of the program.

The generai category of the soils that are removed
needs to be determined. The types of soils can be
generally classified into five groups:

* Pigmented drawing compounds are used in
process steps where the metal is extruded
through dics to produce parts. The most
commonly used pigmented compounds contain
one or more of the following substances:
whiting, lithopone, mica, zinc oxide, bentonite,
flour, yraphite, white. lead, molybdenum
disulfide. titanium dioxide, and soap-like
materials. :

¢ Unpigmented oil and grease include common ©
shop oils and greases such as drawing lubricants,
* rust preventive ils, and quenching oils.

_Formine lubricants and fluids used for
machining can be classified into three
subgroups: (1) hydrocarbon-based oils: piain
or sulfurized mineral and fatty oils (or a
combination of the two), chlorinated mineral
oils, and sulfurized chlorinated mineral oils, (2)
soluble/emulsifiable oils: conventional or heavy
duty solubic oils containing sulfur or other
compounds, glycol ethers, glycois or other
emulsificrs added, and (3) water soluble:
chemical cutting fluids that are water soluble
and contain soaps, amines, sodium salts of
sulfonated fatty alcohols, and alkyl aromatic
salts of sulfonates.

.

* Polishing and buffing compounds can also be
classified into three subgroups: (1) liquids:
mineral oils and oil-in-water emulsions or
animal and vegetable oils with abrasive
materials, (2) semi-solids: oil-based containing
abrasives and emulsions or water-based
containing abrasive and dispersing agents, and
(3) solids: grease containing stearic acid,
hydrogenated fatty acids. tallow, hydrogenated

.. glyceride, petroleum waxes, and combinations
that produce either saponifiable or
nNonsaponifiable materials in addition to -
abrasive materials.

* Miscellaneous surface contaminants such as
lapping compounds. residue from magnetic
Particle inspection, hand oils, shop dirt, chips,
airborne dust, finger grease, ink marks, barrier
cream, or hand protective cream and metal
Pieces also exist.



44

N-METHYL-2-
PYRROLIDONE

N-Methyl-2-Pyrrolidone, also referred to as M-
Pyrole or NMP is miscible with water and most
other organic solvents including esters, ethers,
alcohols, ketones, aromatic and chlorinated
hydrocarbons, and vegetable oils. It has powerful
solvent properties as evidenced by its Physio-
chemical properties. These properties include a
solubility parameter of 11.0, high purity. high flash

effective in ultrasonics applications and cavitates at
both room temperature and elevated temperatures
in its 100 percent active form. Metal substrates
that have been successfully tested with NMP
include carbon steels, stainless steel 304, 316, 317,
Carpenter 20CB3 Admiralty brass, Cupro-Nickel
and ferralium. Several polymeric materials such as
Epoxy-Urethane are sensitive to NMP. Exhibit 13

summarizes the solvent’s principal properties.
Exhibit 12 shows two typical process equipment ~
designs that have been used Successfully for both
batch and in-line operations.

point, and low volatility.

Testing of NMP for specific cleaning applications
is underway. Initial results indicate that NMP is

Exhibit 12

SUMMARY OF PROPERTIES
OF N-METHYL-2-PYRROLIDONE

Empirical Formula
Molecular Weight
Freezing Point

CsHyNO
99.1
-24.4°C (-11.9°F)

Boiling Point 202°C (395°F) @ 760 mm
Vapor Pressure (20°C) +0.29 mm
Viscosity (25°C) 1.65 cp
Specific Gravity 1.027
Interfacial Surface Tension (25°C) 40.7 dynes/cm
Flash Point (open cup) 95°C (204°F)
(closed cup) 93°C (199°F)

0.058 grams/filter - lower limit

2.18% vapor in air - 360°F (182°C)

0.323 gramsfliter - upper limit

12.24% vapors in air - 370°F (188°C)

719 K cal/mol

0.40 K cal/kg at 20°C

127.3 K cal/kg (230 BTU/b)

Completely miscible with water and most organic
solvents including alcohols, ethers, ketones, aromatic
and chlorinated hydrocarbons and vegetable oils.

Explosive limits

Heat of Combustion

Specific Heat

Heat of Vaporization
Miscibility with Other Solvents

Source: GAF Chemical



a9

GLOSSARY

Acute toxicity -- The short-term toxicity of a product in a single dose: Can be divided into oral, cutaneous and
fespiratory toxicities. -

Adsorption — Not to be confused with absorption. Adsorption is a surface phenomenon which some products
can exhibit, whereby they can form a physicochemical bond with many substances, :

Alcohols -- A series of hydrocarbon derivatives with at least one hydrogen atom replaced by an -OH group.
The simplest alcohols (methanol, ethanol. n-propanol, and isopropanol) are good solvents for some organic
soils, notably rosin, but are flammable and can form explosive mixtures with air: their use requires caution
and well-designed equipment.

Aqueous cleaning -- Cleaning parts with water to which may be added suitable detergents, saponifiers or other
additives. : “

Azeotrope -- A mixture of chemicals is azeotropic if the vapor composition is identical to that of the liquid
phase. This means that the distillate of an azeotrope is theoretically identical to the solvents from which it
is distilled. In practice, the presence of contaminants in the solvent slightly upsets the azeotropy,

Biodegradable — Products in wastewater are classed as biodegradable if they can be easily broken down or
digested by, for example, sewage treatment.

BOD - An abbreviation for biochemical oxygen demand.
CFC - An abbreviation for chlorofluorocarbon.

CFC-113 -- A common designation for the most popular CFC solvent. 1,1,2-trichloro-1,2,2-trifluoroethane,
with an ODP of approximately 0.8.

Chelation - is the solubilization of a metal salt by forming a chemical complex or sequestering. One way of
doing this is with ethylenediaminetetra-acetic acid (EDTA) salts which have a multi-dentate spiral ligand form
that can surround metallic and other ions.

Chlorofluorocarbon - An organic chemical composed of chlorine, fluorine and carbon atoms, usually
characterized by high stability contributing to a high ODP.

Chronic toxicity - The long-term toxicity of a product in small, repeated doses. Chronic toxicity can often
take many years to determine.

COD - An abbreviation for chemical oxygen demand.

Detergent — A product designed to render, for example, oils and greases soluble in water, usually made from
synthetic surfactants.

Fatty acids — The principal part of many vegetable and animal oils and greases, also known as carboxylic acids
which embrace a wider definition. These are common contaminants for which solvents are used in their
removal. ‘They are also used to activate fluxes.



27

ALTERNATIVE MATERIALS AND PROCESSES

A number of alternative cleaning processes and alternative solvents to CFC-113 and MCF

are now available for metal cleaning operations. The choice of an alternative depends on
cleaning needs and process selection factors. .

Alternative Cleaning Processes:
« Aqueous
¢ Semi-Aqueous

Alternative Solvents:

Hydrochlorofluorocarbons

Aliphatic Hydrocarbons
N-Methyl-2-Pyrrolidone

Miscellaneous Solvents

The following sections describe the major advantages, disadvantages. and key process issues
of several alternatives.

Provision of this material in no way constitutes EPA or ICOLP recommendation or approval
of any company or specific offering. These technologies should be evaluated on a case-by-

case basis. A list of vendors and references at the end of this manual may be a useful
additional source of information. :



INTRODUCTION TO METAL CLEANING

Cleaning is an essential pfocess in the production.
maintenance, and repair of manufactured articles.
As a surface preparation process, cleaning removes
contaminants and prepares raw materials and parts
for subsequent operations such as machining,
painting, electroplating, inspection. and packaging.
Cleaning is used in furniture and fixtures. primary
metal industries, fabricated metal products,
machinery, transportation equipment. and other
miscellaneous manufacturing. :

Chlorofluorocarbon 113 (CFC-113) and methyl
chloroform (MCF) have been used for many
solvent, cleaning applications. These solvents
exhibit good solvency for a wide variety of organic
contaminants and are noncorrosive to the metals
being cleaned. They have low heats of
vaporization and high vapor pressures that are
beneficial in vapor cleaning processes and allow
evaporative drying of cleaned‘parts. Additionaily,
these solvents are non-flammable, have low
toxicity, and chemically stable when properiy
formuiated with adequate stabilizers.

Solvent cleaning may be divided into two types:
cold cleaning and vapor degreasing. Cold cleaning

" is usually accomplished with solvents at. or slightly

above. room temperature: In cold cleaning, parts
are cleaned by being immersed and soaked,
sprayed, or wiped with the solvent.

Vapor degreasing is a process that uses the boiling
solvent vapor to remove contaminants. A basic
vapor degreaser consists of an open-top steel tank
that has a heat source at the bottom to boil the
solvent and cooling coils near the upper section to
condense the vapors.

Heat, introduced into the reservoir. boils the
solvent and generates hot solvent vapor which
displaces the lighter air and forms a vapor zone
above the boiling solvent up to the cooling zone.
The hot vapor is condensed when it reaches the
cooling zone by condensing coils or a water jacket,
thus maintaining a fixed vapor level and creating a

thermal balance. The hot vapor condenses on the
cool part suspended in the vapor zone causing the
Solvent to clissolve or displace the contaminants or
soils. :

Vapor degreasing is, in most applications, more
advantagcous than cold cleaning, because in cold
cleaning the solvent bath becomes increasingly
contaminated. Although the boiling solvent
contains the contaminants from previously cleaned
Parts. these usually hoil at higher temperatures
than the solvent, resulting in the formation of
essenually pure solvent vapors. In addition, the
high temperature of vapor cleaning aids in wax and
heavy grease removal as well as significantly
Teducing the time it takes for cleaned parts to dry.



55

Maintain Equipment

All equipment should be regularly maintained.
Metal tanks should be .properiy coated with
protective finishes. Deionized water should be
used in tanks with plastic lining. Spray nozzles
should be inspected regularly to avoid clogging.
Another important item that should be maintained
is float valves that supply make-up water. Leaks in
these valves can cause dilution of cleaner. It is
also important to determine whether plastic
material used in equipment is compatible with the
hydrocarbon material used in the semi-aqueous
process,

Consider Other Process Design
Features

Other process design features that reduce
wastewater discharge include:

¢ Use of demineralized water for cleaning needs
that cannot tolerate minor residue on the parts.

Rinsing should be carried out using.

demineralized water. This water reduces the
~ amount of sludge generated during wastewater

treatment and may allow the direct use of rinse

water as make-up water for the wash tank;

* Counterflow rinse systems should always be
used to reduce overall water consumption and
subsequent treatment requirements;

« Fog nozzles use much less water than
conventional spray systems.

Wastewater Treatment
Technologies

Wastewater generated from. these processes can
have a wide range of pollutants; therefore, the
treatment technologies applied will depend on the
type of pollutant present and the quantity of
wastewater being generated. The wastewater
treatment equipment .and processes discussed
below are categorized based on the type of
pollutant being treated.

Oil and Grease

Gravity Separator. This treatment technology takes
advantage of the difference in specific gravity
between water and oil and grease. Gravity
separators are the most common devices employed
in waste treatment to separate grease and non-
emulsified oils. The technique does not always
remove very finely divided (colloidal) oily or
scummy material. The process generates an oily
dispersion that may have to be treated prior to
disposal. Relative energy requirements are tow. .
The treatment process involves retaining the oily
waste in a holding tank and allowing gravity
separation of the oily material which is then
skimmed from the wastewater surface,

In instances where the quantity of wastewater to be.
treated is small, a simple skimmer attached to a
tank can be used to remove the free floating oils ~
a process commonly used in metal cleaning. The
oil skimmers either are operated continuously
during cicaning or are operated once a day before
the cleaning process is started. It should be noted
that during the removal of oil, other suspended

- solids, like metal fines and chips, are also removed.

Ultrafiltration. Ultrafiltration is a low pressure (10-
150 psi) membrane process for separating high
molecular weight emulsified oils and particulate

_Matter Icss than 0.2 microns in diameter. A semi-

permeable membrane, incorporated in membrane
modules. performs the separation. The wastewater
feed is pumped under pressure tangentially
through:the membrane modules. Water and low-
molecular weight-solutes such as salts and some
surfactants, pass orthogonal to the direction of
flow through the membrane pores as permeate.
The solution may be reused or further treated
prior to disposal. Emulsified.oil and suspended
solids cannot pass through the membrane pores
and are retained as a concentrate. Capital cost for
ultrafiltration equipment and operating costs
associated with pumping the solution at elevated
pressure are higher than other treatment methods.
Material and disposal cost savings can provide an
acceptable return on investment in cases where
recycling of the permeate solution is possible.

Wastewater flows across the membrane surface at
high velocity. ‘This cross-flow characteristic differs
from the perpendicular flow of ordinary filtration,



Table of Contents (Continued)

Wastewater Minimization and Treatment ...........2..00cccccccececcccece 53°

Contaminants ........
Wastewater Minimization
Wastewater Treatment Technologies
Conceptual Design of a Wastewater Treatment System . .

Contract Hauling of Wastewater .... 20... ec ccc e cece cee eceeceuace
Summary and Review ..... 6.00... c eee cece cee e cece en senteneenccs 61

Case Studies of Industrial Practices ............0..0. 0. cc eeeeeeee enna cee 63

Case Study #1: Evaluation of Aqueous Cleaning tor Aluminum and

Ferrous Alloys .... 0.00... 0c ccc e eee ee ee enetseeuees 65
Case Study #2: Selection of Aqueous Process for Cleaning Components

for Solenoid Valves 2.0.0... 0. cece cece cece ences ete ecteeceeucs 69
Case Study #3: A Five-Phase Program for Developing Alternative

Cleaning... 0... eee ccc cece cent ete ecencneenee 72
Case Study #4: Program to Eliminate Wipe Solvents Containing ;

5 SO 9 74
Case Study #5: Biodegradable Replacements for Halogenated Solvents

and Cleaners .......... 00... e cece eee e eee ea tee cece eet ewvens 75

Case Study #6: Replacement of Solvent Degreasing for Engineering

Prototype Parts, Precision Machine Parts, and Various Cleanroom Items .... 79
Case Study #7: Program to Eliminate Methyl Chloratorm Use in

Steel Chair Manufacturing Operations ............. “Lene e ee eee ee eens 80

References ......... cc cece cece ee eee Nee ee ence cece eee eet e ee eneen BS



Stoelting Inc.,

502 Highway 67

PO Box 127

Kiel, WI 53042

Tel: (414) 894-2293
Fax: (414) 894-7029

Hydrocarbon/Surfactant

Crest Ultrasonics Corp.
P.O. Box 7266

Scotch Road

Mercer County Airport
Trenton, NJ 08628
Tel: (609) 883-4000

DuPont Chemicals
Customer Service
B-15305

Wilmington, DE 19898
Tel: 1-800-441-9450

Golden Technologies Company, Inc.
Biochem Systems Division

15000 W. 6th Avenue

Suite 202

Golden, CO 80401

Tel: (303) 277-6577

Fax: (303) 277-6550

Penetone Corporation
74 Hudson Avenue
Tenafly, NJ 07670
Tel: (201) 567-3000

Union Camp

P.O. Box 37617
Jacksonville, FI. 32236
Tel: (904) 783-2180

Alcohol Cleaning Equipment

Electronic Control Design
13626 South Freeman Road
Milwaukie, OR 97222-8825
Tel: (503) 829-9108

Fax: (S03) 659-4422

Unique Industries
11544 Sheldon St.
P.O. Box 1278

Sun Valley, CA 91353
Tel: . (213) 875-3810

Detrex Corporation

P.O. Box 569

401 Emmett Ave.
Bowling Green, KY 42102
Tel: (502) 782-1511

Electrovert Corp.
4330 Beltway Place |
Suite 350

Arlington. TX 76017
Tel: (817) 468-5171

Orange-Sol Inc.
Dennis Weinhold
P.O. Box 306
Chandler, AZ, 85244
(602) 497-8822

Petroferm

5400 East Coast Highway
Fernandina Beach, FL 32034-
Tel: (904) 261-8286

Fax: (904) 261-6994

Herbert Streckfus GmbH

Elektronik-Sondermaschinenbau

7814 Eggenstein 1
Kruppstrabe 10
Germany

Tel: (0721) 70222-24
Telex: 7 826 566
Te: 721119
Fax: 0721/785966



AQUEOUS CLEANING PROCESS EQUIPMENT

IMMERSION WITH
ULTRASONIC
AGITATION

IMMERSION
WITH MECHANICAL
AGITATION

SPRAY WASHER .

ADVANTAGES

Highest level of
cleaning; cleans complex
parts/ configurations
Can be automated

Usable with parts on
trays

Low maintenance

Usable with parts on
trays

Will flush out chips .
Simple to operate

Cleans complex parts
and configurations

Can use existing vapor
degreasing equipment
with some simple
engineering changes.

High level of cleanliness ;
Inexpensive

Will flush out chips
Simple to operate

High volume

Portable

Short lead time

DISADVANTAGES

Highest cost

Requires rinse water for
some applications

Requires new basket
design

Long lead time
Can’t handle heavy oils

Limits part size and tank
volumes

May require separate
drye

Requires rinse water for
some applications

Harder to automate
Requires proper part

orientation and/or
changes while in solution

May Trequire separate
dryer

Requires rinse water for
some applications to
prevent film residues

Not effective in cleaning
complex parts

May require separate
dryer



94

government bodies to develop the most efficient
means of creating, gathering, and distributing
information on alternatives.

One example of ICOLP’s activities is the
development and support of an alternative
technologies electronic database "OZONET."
OZONET is accessible worldwide and has relevant
information on the alternatives to ozone-depleting
solvents, OZONET not only contains technical
Publications, conference papers, and reports on the
Most recent developments of alternatives to the
Current uses of ozone-depleting solvents, but it also
contains:

¢ Information on the health, safety and
environmental effects of alternative chemicals
and processes;

* Information supplied by companies developing
alternative chemicals and technologies;

¢ Names, addresses, and telephone numbers for
technical experts, ‘government contacts,
institutions and associations, and other key
contributors to the selection of alternatives;

Dates and places of forthcoming conferences,
seminars, and workshops;

* Legislation that has been enacted or is in place
internationally, nationally, and locally.

Information about ICOLP can be obtained from:

Mr. Steven B. Hellem
Executive Director

ICOLP

1440 New York Avenue, N.W.
Suite 300

Washington, D.C. 20005

Tel: (202) 737-1419

Fax: (202) 639-8685



Exhibit 9

SEMI-AQUEOUS PROCESS FOR
IMMISCIBLE HYDROCARBON SOLVENT

Parts to
be Clasned

|
Hydrocarbon
Surtactant | “ane Rinse Forced Hot Al
Wash Stage ' . .

i
ftydrocarvow A eccn
Surtactant
. @ Closed Loop Water
Reuse : Treatment
Olspose or ieeietied
Recycie > ® Site Water

’ : @ Direct to Orain
' Decanter