EL DORADO COUNTY AIR QUALITY MANAGEMENT DISTRICT
RULE 225 - ORGANIC SOLVENT CLEANING AND DEGREASING OPERATIONS
(Adoption Date: September 27, 1994)
- PURPOSE: To limit the emission of volatile
organic compounds from degreasers.
- The provisions of Section 225.3 B., of this rule do not apply to non-vapor degreasers
which have an air-solvent interface area less than or equal to 1.0 ft2, or to remote reservoir degreasers using a non-volatile solvent spray which is drained into
the remote reservoir concurrently with the degreasing operation.
- The provisions of Section 225.3 F.7., of this rule do not apply to open-top vapor
degreasers where solvent flow is conducted pursuant to Section 225.3 F.10.b., and liquid solvent does not splash
above the air-vapor interface.
- CONVEYORIZED DEGREASER: Any continually loaded,
conveyorized degreaser, using solvent that is maintained either above or below the initial boiling point temperature
of the solvent.
- DEGREASER: A container that contains solvent
or into which solvent is sprayed and concurrently drained, used to remove oil, grease, soil, coating, dirt or other
undesirable matter from workloads.
- EXEMPT COMPOUNDS: The following compounds are
exempt from the definition of VOC in Section 225.2 Q.:
- methane (CH4)
- carbon dioxide (CO2)
- carbon monoxide (CO)
- carbonic acid ((CO(OH)2)
- metallic carbides (M-C) or carbonates (M-CO3)
- ammonium carbonate ((NH4)HCO3(NH4)CO2NH2)
- 1,1,1-trichloroethane (methyl chloroform)
- methylene chloride (dichloromethane)
- trichlorofluoromethane (CFC-11)
- dichlorodifluoromethane (CFC-12)
- chlorodifluoromethane (HCFC-22)
- trifluoromethane (HFC-23)
- 1,1,1-trichloro-2,2,2-trifluoroethane (CFC-113)
- 1,2-dichloro-1,1,2,2-tetrafluoroethane (CFC-114)
- chloropentafluoroethane (CFC-115)
- 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123)
- 2-chloro-1,1,1,2-tetrafluoroethane (HCFC-124)
- pentafluoroethane (HFC-125)
- 1,1,2,2-tetrafluoroethane (HFC-134)
- 1,1,1,2-tetrafluoroethane (HFC-134a)
- 1,1-dichloro-1-fluoroethane (HCFC-141b)
- 1-chloro-1,1-difluoroethane (HCFC-142b)
- 1,1,1-trifluoroethane (HFC-143a)
- 1,1-difluoroethane (HFC-152a).
- The following classes of perfluorocarbon compounds:
- Cyclic, branched, or linear, completely fluorinated alkanes,
- Cyclic, branched, or linear, completely fluorinated ethers, with no unsaturations,
- Cyclic, branched, or linear, completely fluorinated tertiary amines with no unsaturations.
- Sulfur-containing perfluorocarbons with no unsaturations and with sulfur bonds only
to carbon and fluorine.
- FREEBOARD HEIGHT:
- For non-vapor degreasers, freeboard height means the distance from the top of the
solvent to the top of the tank.
- For vapor degreasers, freeboard height means the distance from the solvent vapor-air
interface to the top of the degreaser.
- For conveyorized degreasers, freeboard height means the distance from the top of the
solvent (non-vapor solvent) or the top of the vapor-air interface (vapor degreaser), to the bottom of the lowest
opening where solvent vapors can escape.
- FREEBOARD RATIO: The freeboard height divided
by the smaller of the inside length or the inside width of the degreaser's evaporative surface area.
- LEAK: Three or more drops of liquid solvent
- LIP EXHAUST: A system which collects solvent
vapors escaping from the top of a degreaser and directs them away from operating personnel.
- LOW VOLATILITY SOLVENT: Any solvent with an
initial boiling point which is greater than 248oF
(120oC) and with a temperature as used,
at least 100oC (180oF) below the initial boiling point as determined pursuant
to Section 225.5 B.1.
- MAKEUP SOLVENT: The solvent added to the degreaser
to replace solvent lost through evaporation or other means.
- NON-VAPOR DEGREASER: Any degreaser using solvent
which, if heated, is maintained below the initial boiling point temperature of the solvent.
- OPEN-TOP VAPOR DEGREASER: Any batch-loaded
degreaser using solvent which is maintained above the initial boiling point temperature of the solvent. Degreasing
occurs through the condensation of the resultant solvent vapor onto the surface of the workload.
- OSHA: Occupational Safety and Health Administration.
- REFRIGERATED FREEBOARD CHILLER: A secondary
cooling coil mounted above the primary condenser which provides a chilled air blanket above the solvent vapor-air
interface to cause the condensation of additional solvent vapor, thereby increasing vapor control efficiency.
- REMOTE RESERVOIR DEGREASER: A non-vapor degreaser
with a tank which is completely enclosed except for a solvent return opening no larger than 15.50 square inches
(100 square centimeters) which allows used solvent to drain into it from a separate solvent sink or work area and
which is not accessible for soaking workloads.
- SOLVENT: VOC-containing compounds which are
used as diluents, thinners, dissolvers, viscosity reducers, or cleaning agents.
- STATIONARY SOURCE: Any building, structure,
facility, or emissions unit which emits or may emit any affected pollutant directly or as a fugitive emission.
- Building, structure, facility, or emissions unit includes all pollutant emitting activities
- Belong to the same industrial grouping, and
- Are located on one property, or two or more contiguous properties, and
- Are under the same or common ownership, operation, or control, or which are owned
or operated by entities which are under common control.
- Pollutant emitting activities shall be considered as part of the same industrial grouping
- They belong to the same two-digit Standard Industrial Classification (SIC) code, or
- They are part of a common production process, which includes industrial processes,
manufacturing processes and any connected processes involving a common material.
- VOLATILE ORGANIC COMPOUNDS (VOC): Compounds
containing at least one atom of carbon, except for the compounds listed in Section 225.2 C.
- VOLATILE SOLVENT: Any solvent which is not
defined as a low volatility solvent pursuant to Section 225.2 H.
- WIPE CLEANING: That method of cleaning which
utilizes a material such as a rag wetted with a solvent, coupled with a physical rubbing process to remove contaminants
- WORKLOAD: The objects put in a degreaser for
the purpose of removing oil, grease, soil, coating, dirt or other undesirable matter from the surface of the objects.
- GENERAL EQUIPMENT REQUIREMENTS: Any person
who uses a degreaser shall utilize the following equipment:
- An apparatus or cover which prevents the solvent from evaporating when not processing
work in the degreaser.
- For non-vapor degreasers using volatile solvent, or solvent that is agitated, the
cover should be a sliding, rolling or guillotine (bi-parting) type which can be opened and closed easily with one
- For open-top vapor degreasers, the cover should be a sliding, rolling or guillotine
(bi-parting) type which can be opened and closed easily without disturbing the vapor zone.
- For conveyorized degreasers, a cover shall be provided for closing off the entrance
and exit during shutdown hours.
- A facility for draining cleaned parts such that the drained solvent is returned to
- A permanent, conspicuous label which summarizes operating requirements contained in
Sections 225.3 D., through 225.3 F., of this rule.
- NON-VAPOR DEGREASERS; EQUIPMENT REQUIREMENTS:
A person shall operate non-vapor degreasers, including remote reservoirs (except as noted in Section 225.1 B.2.),
using one of the following control devices:
- Non-vapor degreasers shall operate with a freeboard ratio equal to or greater than
0.75 if using solvents which are:
- Agitated, or
- Heated above 122oF
- Non-vapor degreasers using only low volatility solvents which are not agitated shall
operate with a freeboard height of at least 6 inches.
- A water cover may be used as an acceptable alternative to Sections 225.3 B.1., and
225.3 B.2., if the solvent is insoluble in water and has a specific gravity greater than 1.
- VAPOR DEGREASERS; EQUIPMENT REQUIREMENTS: A
person shall operate vapor degreasers using the following control devices:
- A freeboard ratio greater than or equal to 0.75.
- A refrigerated freeboard chiller for which the chilled air blanket temperature (oF) at the coldest point on the vertical axis in the center
of the air-vapor interface shall be no greater than 30% of the initial boiling point (oF) of the fresh solvent used or no greater than 40oF. If the chiller operates below the freezing temperature of water, it shall be equipped with
an automatic defrost.
- A carbon adsorption system which ventilates the air-vapor interface at a minimum rate
of 15 m3/min/m2, but not greater than 20 m3/min/m2, unless necessary to meet Federal and State OSHA requirements,
with a solvent vapor concentration exiting the exhaust duct of the carbon adsorber of less than 25 ppm solvent
averaged over one complete adsorption cycle.
- A primary condenser.
- VAPOR DEGREASERS; SAFETY SWITCHES: If a vapor
degreaser is used, then the following equipment shall be utilized:
- A device which shuts off the sump heater if the condenser coolant stops circulating
or becomes warmer than specified.
- For degreasers of the spray type, a device which prevents spray pump operation unless
the solvent vapor level is at the designed operating level.
- A device (of the manual reset type) which shuts off the sump heater if the solvent
vapor level rises above the designed operating level.
- CONVEYORIZED DEGREASERS: In addition to the
requirements of Sections 225.3 B., and 225.3 C., a person shall not operate a conveyorized degreaser unless it
is equipped with the following control devices:
- Either a drying tunnel or other means such as a rotating basket, sufficient to prevent
cleaned parts from carrying out solvent liquid or vapor.
- Minimized opening: entrances and exits should silhouette workloads so that the average
clearance between parts and the edge of the degreaser opening is either less than 4 inches (10 cm) or less than
10 percent of the width of the opening.
- A primary condenser.
- A vapor level control thermostat.
- A condenser flow switch.
- A spray safety switch.
- A freeboard ratio greater than or equal to 0.75 which is physically verifiable, or
a refrigerated freeboard chiller for which the chilled air blanket temperature (oF) at the coldest point on the vertical axis in the center of the air-vapor interface shall
be no greater than 30 percent of the initial boiling point (oF) of the solvent used or no greater than 40o F. If the chiller operates below the freezing temperature of water, it shall be equipped with
an automatic defrost.
- GENERAL OPERATING REQUIREMENTS: Any person
who uses a degreaser must conform to the following operating requirements:
- Operate and maintain the degreaser and emission control equipment in proper working
- Do not allow any solvent to leak from any portion of the degreaser.
- All solvent, including waste solvent and waste solvent residues, shall be stored in
closed containers at all times. The containers shall have a label indicating the name of the solvent/material they
- If distillation recovery of waste solvent is performed, solvent residues shall not
contain more than 10 percent solvent by volume after distillation.
- Do not remove or open any device designed to cover the solvent unless processing work
in the degreaser or performing maintenance on the degreaser.
- Drain cleaned parts after cleaning until dripping ceases (non-vapor degreaser only).
- If using a solvent flow, use only a continuous, fluid stream (not a fine, atomized,
or shower type spray) at a pressure which does not cause liquid solvent to splash outside of the degreaser.
- Perform solvent agitation, where necessary, by means other than air agitation.
- Do not degrease porous or absorbent materials such as cloth, leather, wood, or rope.
- For vapor degreasers:
- Workloads shall not occupy more than half of the degreaser's evaporative surface area.
- Solvent spray shall be kept at least 4 inches below the air-vapor interface.
- When starting the degreaser, the cooling system shall be turned on before, or simultaneously
with, the sump heater.
- When shutting down the degreaser, the sump heater shall be turned off before, or simultaneously
with, the cooling system.
- The degreaser shall be covered whenever the cooling system is off.
- A person shall minimize solvent carry-out by the following measures, as applicable:
- Rack workload to facilitate drainage;
- Move workload in and out of the degreaser at less than 3.3 m/min (11 ft/min);
- Degrease the workload in the vapor zone until condensation ceases;
- Allow workload to dry within the degreaser until visually dry;
- For manual operation, tip out any pools of solvent remaining on the workload before
removing it from the degreaser.
- A cleaner shall not be located where drafts are directed across the cleaner.
- For those cleaners equipped with water separators, no solvent shall be visually detectable
in the water exiting the water separator.
- LIP EXHAUST: Effective September 27, 1994,
a lip exhaust system shall not be added to any degreaser, unless it is vented to an emission control system, pursuant
to Section 225.3 H. The lip exhaust shall be turned off when the degreaser is covered.
- EMISSION CONTROL SYSTEM REQUIREMENTS: Any person
or stationary source subject to this rule may use an emissions control system as an alternative to Sections 225.3
B., 225.3 C.1., or 225.3 C.2., provided that the system has an overall control efficiency (the collection efficiency
multiplied by the control efficiency) of at least 85 percent on a mass basis, as determined pursuant to Sections
225.5 B.2., and 225.5 B.3. The emission collection system shall have a ventilation rate not greater than 20 cubic
meters per minute per square meter over the total area of the degreaser's evaporative surface area, unless the
rate must be changed to meet Federal and State OSHA requirements.
225.4 ADMINISTRATIVE REQUIREMENTS
- COMPLIANCE SCHEDULE: Any person or stationary
source subject to this rule, including previously exempt sources, shall be in compliance with Sections 225.3 B.2.,
225.3 C.2., and 225.5 A., by March 27, 1995
- CALCULATION FOR DETERMINATION OF VOC CONTENT PER VOLUME OF SOLVENT: The volume of solvent is defined as the volume of the original solvent, plus any VOC-containing
material added to the original solvent. The weight of VOC per volume of solvent shall be calculated by the following
OPERATION AND MAINTENANCE PLAN: Any person
using an approved emission control device pursuant to Section 225.3 H., as a means of complying with this rule,
as provided in Sections 225.3 B., 225.3 C.1., or 225.3 C.2., must submit, with the application for Authority to
Construct, pursuant to Rule 501, General Permit Requirements, an Operation and Maintenance Plan for the emission
control device to the Air Pollution Control Officer for approval. Plans for emission control devices installed
as of September 27, 1994, if not previously
submitted, must be submitted by March 27, 1995
and receive approval of the Air Pollution Control Officer. The Plan shall specify operation and maintenance procedures
which will demonstrate continuous operation of the emission control device during periods of emissions-producing
operations. The Plan shall also specify which records must be kept to document these operation and maintenance
procedures. These records shall comply with the requirements of Sections 225.5 A.2., and 225.5 A.3. The Plan shall
be implemented upon approval of the Air Pollution Control Officer.
(Wv - Ww
- Wec) / (Vs)
Wv = weight of all volatile compounds.
Ww = weight of water.
Wec = weight of compounds listed as exempt in Section 225.2 C. from the definition of VOC.
Vs = volume of solvent.
- USAGE RECORDS: In addition to any existing
permit conditions issued pursuant to Rule 501, effective September 27, 1994, any person subject to this rule shall
comply with the following requirements:
- USAGE AMOUNTS: The person shall reco