SANTA BARBARA COUNTY AIR POLLUTION CONTROL DISTRICT

RULE 321 - SOLVENT CLEANING OPERATIONS
(Adopted 2/24/1975; Readopted 10/23/1978; Revised 6/11/1979, 7/10/1990, 4/17/1997, 7/17/1997, and 9/18/1997)

A. Applicability

This Rule shall apply to any person who performs solvent cleaning operations.

B. Exemptions

  1. Solvent cleaning operations using solvent (including emulsions) that contain two percent or less of reactive organic compounds by weight (as determined by EPA method 24) shall not be subject to the requirements of this Rule.
  2. Except for the Rule 321 Section G.2 requirement that the cleaner be covered when work is not being processed (use of covers are not required for remote reservoir cold cleaners using low volatility solvents), the provisions of this Rule shall not apply to an unheated solvent cleaner that:

    a. has a capacity of 3.785 liters (1 gallon) or less, or

    b. has an evaporative surface area of less than 929 square centimeters (1 square foot). However, if the aggregate evaporative surface area of all such solvent cleaners at a stationary source is greater than 0.929 square meters (10 square feet), none of the cleaners are exempt.

  3. The provisions of Rule 321 Section J.7 shall not apply to open-top vapor solvent cleaners with less than 1 square meter (10.8 square feet) of evaporative surface area.
  4. The provisions of this Rule shall not apply to:

    a. wipe cleaning,

    b. dry cleaning operations of clothing or other fabrics covered under Rule 320, Petroleum Solvent Dry Cleaners, or 17 California Code of Regulation, Section 93109, Perchloroethylene Airborne Toxic Control Measure--Dry Cleaning Operations,

    c. stripping of cured coatings (e.g., stripping), cured adhesives (e.g., debonding, unglueing) and cured inks,

    d. spray gun cleaning operations,

    e. batch vapor, in-line vapor, in-line cold, and batch cold solvent cleaning machines that uses any solvent containing methylene chloride, perchloroethylene, trichloroethylene, 1,1,1-trichloroethane, carbon tetrachloride, or chloroform, or any combination of these halogenated hazardous air pollutants solvents, in a total concentration greater than 5 percent by weight, as a cleaning and/or drying agent, provided such solvent cleaning machines are subject to 40 CFR, Part 63, Subpart T, National Emission Standards for Hazardous Air Pollutants: Halogenated Solvent Cleaning, or

    f. cold solvent degreasers of 37.854 liters (10 gallons) or less in capacity, provided the degreasers are designed to operate in a closed system fashion (i.e., sealed when operated) and agitated through pump recirculation, mechanical mixing (a mixer), or with ultrasonics. Gas or air agitation shall not be used.

C. Definitions

D. General Operating Requirements

Any person who uses a solvent cleaner shall conform to the following operating requirements:

  1. Solvent, including waste solvent, shall not be stored or disposed of in a manner that will cause or allow evaporation into the atmosphere. Containers shall have a label indicating the name of the solvent/material they contain. After distillation recovery of waste solvent, solvent residues shall not contain more than 20 percent solvent by weight.
  2. The solvent cleaner, ventilation system, and emission control equipment shall be installed, operated, and maintained in proper working order.
  3. Solvent cleaning or solvent vapor cleaning of porous or absorbent materials, such as cloth, leather, wood, or rope, is prohibited.
  4. The solvent container shall be free of all liquid leaks. Auxiliary cleaner equipment, such as pumps, water separators, steam traps, or distillation units shall not have any liquid leaks, visible tears, or cracks. Any such liquid leak, visible tear, or crack that is detected shall be repaired within one day from discovery by the operator, or the cleaner shall be drained of all solvent, in a manner authorized by this Rule, and shut down until replaced or repaired. Solvent cleaners shall not be operated when leaking.
  5. Covers designed to reduce solvent evaporation shall not be removed except to process work or to perform maintenance.
  6. For solvent degreaser operations, solvent carry-out shall be minimized by the following methods, as applicable:

    a. The workload shall be racked.

    b. For manual operations, any pools of solvent remaining on the cleaned parts shall be tipped out before removing them from the cleaner.

    c. Pools of solvent shall be drained by a device.

    d. The workload shall be drained within the freeboard area so that the drained solvent is returned to the container.

    e. For cold solvent cleaning, parts shall be drained immediately after cleaning, until one of the following conditions exists:

    1. At least 15 seconds have elapsed; or
    2. Dripping of solvent ceases; or
    3. The parts become visibly dry.
    f. The workload shall be moved in and out of the degreaser at less than 3.3 meters per minute (11 feet per minute).
  7. For solvent degreaser operations, solvent flow shall be directed downward to avoid turbulence at the air-vapor or air-solvent interface and to prevent liquid solvent from splashing outside of the cleaner.
  8. For solvent degreaser operations, solvent flow shall not be used in a manner such that liquid solvent splashes outside the container.
  9. Solvent atomization operations (e.g., blow drying) shall be vented to an emission control system that meets the requirements of Rule 321 Section M.

E. Additional Operating Requirements for Open-top Vapor Solvent Cleaners and Conveyorized Vapor Solvent Cleaners. In addition to the general operating requirements specified above in Rule 321 Section D, any person who uses an open-top vapor solvent cleaner or a conveyorized vapor solvent cleaner shall conform to the following operating requirements:

  1. The degreaser shall be covered whenever the cooling system is off.
  2. When starting the degreaser, the cooling system shall be turned on before or simultaneously with the sump heater.
  3. When shutting down the degreaser, the sump heater shall be turned off before or simultaneously with the cooling system.
  4. The workload shall be degreased in the vapor zone for at least 30 seconds or until condensation ceases.
  5. Parts shall be allowed to dry within the degreaser until the exterior surface of the parts become visually dry.
  6. Solvent spray shall be kept at least 10 centimeters (3.94 inches) below the air-vapor interface.
  7. The workload area shall not occupy more than half of the evaporative surface area of the solvent cleaner.
  8. For cleaners equipped with water separators, water shall not be visibly detectable in the solvent phase exiting the water separator, nor shall solvent be visibly detectable in the aqueous phase leaving the separator.

F. Additional Operating Requirements for Gas/Liquid-Path Cleaners. In addition to the operating requirements specified in Rule 321 Sections D.1 - D.5 and D.9, any person using a gas/liquid-path cleaner shall conform to the following operating requirements:

  1. Cleaned parts or equipment shall be drained until dripping ceases or 15 seconds have elapsed.
  2. The cover of the solvent reservoir shall be closed at all times except when the reservoir is being filled, emptied, cleaned, repaired or inspected.

G. General Equipment Requirements for Solvent Cleaners. All solvent cleaners shall conform to the following requirements:

  1. A container shall be used for the solvent.
  2. Except for remote reservoir cold cleaners using low volatility solvents, all cleaners shall be equipped with an apparatus or cover(s) to completely cover the solvent container when not processing work.
  3. Solvent degreasers shall be equipped with a facility or device for draining cleaned parts such that the drained solvent or drag-out is returned to the cleaner solvent tank.
  4. The applicable operating requirements contained in Rule 321 Sections D, E, and F shall be legibly written and permanently and conspicuously posted on or near the equipment in such a manner that it is conveniently available to the operator for reference purposes.
  5. Where solvent agitation is used, the agitation shall be achieved using pump recirculation, mechanical mixing (a mixer), or ultrasonics. Gas or air agitation shall not be used.
  6. When employing solvent flow with a solvent degreaser, the flow shall only be a continuous fluid stream. An atomized or shower type spray shall not be used. In a conveyorized or enclosed cleaner, a shower type spray may be used provided that the spray is conducted in a totally confined space that is sealed from the atmosphere.
  7. Any degreaser equipped with a hood, enclosure, or lip exhaust, or a lip exhaust connected to a hood or enclosure, shall not have an air ventilation rate in excess of 20 cubic meters per minute per square meter (65.6 cubic feet per minute per square feet) of air-vapor or air-solvent interface surface area, unless necessary to meet a National Institute for Occupational Safety and Health standard.
  8. Effective July 17, 1997, no person shall install or add a lip exhaust to a degreaser unless it is vented to an emission control system that meets the requirements of Rule 321 Section M.
  9. The average draft rate in the solvent cleaner workroom, as measured parallel to the plane of the degreaser opening, shall not exceed 9.1 meters per minute (30 feet per minute), unless necessary to meet a National Institute for Occupational Safety and Health standard.
  10. Ventilation fans shall not be positioned in such a way as to direct air flow near the degreaser openings.
  11. The vertical speed of any powered hoist or conveyor shall not exceed 3.3 meters per minute (11 feet per minute).

H. Additional Equipment Requirements for Remote Reservoir Cold Cleaners. In addition to the requirements in Rule 321 Section G, remote reservoir cold cleaner equipment shall meet the following requirements:

  1. The sink or work area shall be sloped sufficiently towards the drain to prevent pooling of solvent.
  2. There shall be a single drain hole, not larger than 100 square centimeters (15.5 square inches) in area, for the solvent to flow from the sink into the enclosed reservoir.
  3. Except for remote reservoir cold cleaners using low volatility solvents, the solvent vapor shall be prevented from escaping from the solvent container by means of closing a cover or a device, such as a valve or a drain plug, when the remote reservoir is not being used, cleaned, or repaired.
  4. The freeboard height shall be 6 inches or higher.
  5. The unit shall have a freeboard ratio of 0.75 or greater, if the solvent is heated above 50 degrees Celsius (122 degrees Fahrenheit), agitated, or a high volatility solvent is used.
  6. In lieu of the freeboard height required by Rule 321 Section H.4 or the freeboard ratio required by Rule 321 Section H.5 one of the following requirements shall be met:

    a. a water cover at least 1 inch deep shall be used, provided the solvent is insoluble in water and has a specific gravity greater than 1, or

    b. an emission control system that meets the requirements of Rule 321 Section M shall be used.

I. Additional Equipment Requirements for Cold Cleaners. In addition to the requirements specified in Rule 321 Section G, cold cleaners shall include all of the following:

  1. When using a high volatility solvent, the unit shall be equipped with a cover that is a sliding, rolling, or guillotine type that is designed to easily open and close.
  2. A method for draining cleaned parts, so the drained solvent is returned to the container. If using a high volatility solvent, the drainage facility shall be internal so that the parts are within the solvent cleaner and under the cover while draining. The drainage facility may be external where the internal type cannot fit into the cleaning system provided the drained solvent is returned to the container.
  3. When using a low volatility solvent that is not agitated, the freeboard height shall be 6 inches or higher or a freeboard ratio of 0.5 or greater shall be maintained.
  4. The unit shall have a freeboard ratio of 0.75 or greater, if the solvent is heated above 50 degrees Celsius (122 degrees Fahrenheit), agitated, or a high volatility solvent is used.
  5. In lieu of the freeboard height or freeboard ratio required by Rule 321 Section I.3 or the freeboard ratio required by Section I.4:

    a. a water cover at least 1 inch deep shall be used, provided the solvent is insoluble in water and has a specific gravity greater than 1, or

    b. an emission control system shall be used that meets the requirements of Rule 321 Section M.

  6. A permanent, conspicuous mark shall be maintained locating the maximum allowable solvent level conforming to the applicable freeboard requirements. This requirement does not apply if employing a water cover or an emission control system per Rule 321 Section I.5.

J. Additional Equipment Requirements for Open-top Vapor Solvent Cleaners. In addition to the requirements specified in Rule 321 Section G, open-top vapor solvent cleaners shall include all of the following:

  1. A cover that is a sliding, rolling, or guillotine type that is designed to easily open and close without disturbing the vapor zone. This requirement does not apply to open-top vapor solvent degreasers equipped with top enclosures, provided:

    a. the operator only opens the enclosure cover(s) or door(s) when the condenser is operative or when the degreaser is shut down,

    b. the degreaser evaporative surface area is less than 1 square meter (10.8 square feet) , and

    c. the degreaser cover is designed such that it can be opened and closed easily without disturbing the vapor zone.

  2. A primary condenser coil situated above the boiling solvent.
  3. A condenser flow switch that shuts off the sump heater if the condenser coolant stops circulating or becomes warmer than its designed operating temperature.
  4. A high vapor cutoff thermostat that shuts off the sump heater when the solvent vapor level rises above the designed operating level.
  5. For degreasers with solvent flow, a device that prevents the solvent flow pump operation unless the solvent vapor level is at the designed operating level.
  6. A freeboard ratio of 0.75 or greater.
  7. Cleaners with an evaporative surface area of 1 square meter (10.8 square feet) or greater shall be equipped with one of the following:

    a. A refrigerated freeboard chiller for which the chilled air blanket temperature (expressed in degrees Fahrenheit) 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 (expressed in degrees Fahrenheit) of the solvent used or no greater than 40 degrees Fahrenheit. If the chiller operates below 32 degrees Fahrenheit, it shall be equipped with an automatic defrost.

    b. An enclosed design in which the cover or door opens only when the dry part is actually entering or exiting the cleaner.

  8. In lieu of the freeboard ratio required by Rule 321 Section J.6 or the freeboard chiller/enclosed design required by Section J.7, an emission control system that meets the requirements of Section M may be used.

K. Additional Equipment Requirements for Conveyorized Cold Cleaners. In addition to the requirements specified in Rule 321 Section G, conveyorized cold cleaners shall be equipped with the following:

  1. A rotating basket, tumbling basket, drying tunnel, or other means that prevents cleaned parts from carrying out solvent liquid or vapor.
  2. The average clearance between workload material and the edges of the cleaner entrance and exit openings shall be less than 10 centimeters (3.94 inches) or less than 10 percent of the opening width.
  3. Down-time covers for closing off the entrance and exit during shutdown hours, or an equivalent device that cover at least 90 percent of the opening.
  4. A freeboard ratio of 0.75 or greater that is physically verifiable.
  5. In lieu of the freeboard ratio required by Rule 321 Section K.4, use of an emission control system that meets the requirements of Section M.

L. Additional Equipment Requirements for Conveyorized Vapor Solvent Cleaners. In addition to the requirements specified in Rule 321 Section G, conveyorized vapor solvent cleaners shall be equipped with the following:

  1. A rotating basket, tumbling basket, drying tunnel, or other means that prevents cleaned parts from carrying out solvent liquid or vapor.
  2. The average clearance between workload material and the edges of the cleaner entrance and exit openings shall be less than 10 centimeters (3.94 inches) or less than 10 percent of the opening width.
  3. Down-time covers for closing off the entrance and exit during shutdown hours, or an equivalent device that cover at least 90 percent of the opening.
  4. A primary condenser coil situated above the boiling solvent.
  5. A condenser flow switch that shuts off the sump heater if the condenser coolant stops circulating or becomes warmer than its designed operating temperature.
  6. A high vapor cutoff thermostat that shuts off the sump heater when the solvent vapor level rises above the designed operating level.
  7. For degreasers with solvent flow, a spray pump control switch device that prevents the solvent flow pump operation unless the solvent vapor level is at the designed operating level.
  8. A freeboard ratio of 0.75 or greater that is physically verifiable.
  9. In lieu of the freeboard ratio required by Rule 321 Section L.8, one of the following shall be met:

    a. A refrigerated freeboard chiller for which the chilled air blanket temperature (expressed in degrees Fahrenheit) 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 (expressed in degrees Fahrenheit) of the solvent used or no greater than 40 degrees Fahrenheit. If the chiller operates below 32 degrees Fahrenheit, it shall be equipped with an automatic defrost; or

    b. An emission control system that meets the requirements of Rule 321 Section M shall be used.

M. Emission Control System Requirements. Any person owning or operating a solvent cleaner subject to this rule may use an emission control system as an alternative to Rule 321 Sections D.9, G.8, H.6.b, I.5.b, J.8, K.5, or L.9.b, provided that:

  1. The overall efficiency (the capture system efficiency multiplied by the control device efficiency) of the total system shall not be less than 85 percent by weight in reducing total reactive organic compound emissions.
  2. When using carbon adsorption, the system exhaust shall be no more than 25 parts per million of solvent by volume, calculated as carbon, over a complete adsorption cycle,
  3. The emission collection system shall have a ventilation rate between 15 to 20 cubic meters per minute per square meter of air-vapor or air-solvent interface area (49.2 to 65.6 cubic feet per minute per square feet of air-vapor or air-solvent interface surface area), unless otherwise required to meet a National Institute for Occupational Safety and Health standard.
  4. An application for installation of the emission control equipment is submitted and the Control Officer grants an Authority to Construct for the equipment.

N. Test Methods.

  1. The reactive organic compound content of solvents shall be measured by the Environmental Protection Agency Reference Method 24 (40 CFR, Part 60, Appendix A).
  2. The initial boiling point of solvents shall be determined by ASTM D-1078-86, "Standard Test Method for Distillation Range of Volatile Organic Liquids."
  3. The capture system efficiency shall be determined in accordance with the Environmental Protection Agency method described in 40 CFR, §52.741(a)(4)(iii).
  4. The control device efficiency shall be determined pursuant to the Environmental Protection Agency method described in 40 CFR, §52.741(a)(4)(iv).
  5. The volumetric flowrate shall be determined in accordance with the Environmental Protection Agency Methods 2, 2A, 2C, and 2D.
  6. The average workroom draft rate shall be measured parallel to the plane of the degreaser opening with a thermistor anemometer with an accuracy within ± 2 feet per minute and a calibration pursuant to the National Institute of Standards and Technology.
  7. The identity of components in solvents shall be determined using manufacturer's formulation data or by using ASTM E168-67, ASTM E169-87, or ASTM E260-85.
  8. Emissions of ROC from the exhaust of an emission control system shall be measured by the appropriate EPA Method 18 or 25, or, if applicable, 25A or 25B may be used (40 CFR, Part 60, Appendix A).

O. Operational and Maintenance Plan. Any person proposing to use an emission control device to comply with this rule pursuant to Rule 321 Section M shall submit, with the Authority to Construct application, an emission control device Operation and Maintenance Plan to the Control Officer for approval. Owners or operators of emission control devices installed as of July 17, 1997, if not previously submitted, shall submit Operation & Maintenance Plans by January 17, 1998 and obtain approval of the plan by the Control Officer. The Operation and Plan shall specify:

  1. operation and maintenance procedures of emissions-producing operation, and
  2. which records shall be kept to document these operation and maintenance procedures.

These records shall comply with the requirements of Rule 321 Section P.1.c and P.3. The Plan shall be implemented upon approval of the Control Officer.

P. Recordkeeping.

  1. Any person holding a permit for a solvent cleaner that is subject to this rule shall comply with the following requirements:

    a. Maintain and have available on site solvent manufacturer specification sheets that show the following information for each solvent:

    1. Type of solvent (chemical or manufacturer's product name).
    2. The solvent initial boiling point.
    b. Record each quarter the following information for the stationary source:
    1. The total volume of make-up solvent used, itemized by each solvent's chemical or manufacturer's product name. If the solvent is a mix of materials blended by the operator, the mix ratio by each solvent's chemical or manufacturer's product name shall be recorded.
    2. The date each time waste solvent or waste solvent residue is removed from the facility for disposal.
    c. If using an emission control system pursuant to Rule 321 Section M as a means of complying with this rule, the person shall maintain such records as required by the Operation and Maintenance Plan in Section O on a daily basis.
  2. Any person claiming an exemption from Rule 321, pursuant to Section B.2.b, shall record each quarter the following information for the stationary source: the aggregate evaporative surface area of all solvent cleaners subject to the Rule 321 Section B.2.b exemption claim.
  3. Records kept pursuant to this section shall be maintained on site for at least 2 years. Thereafter, the records shall be maintained either on site or readily available for expeditious inspection and review for an additional 3 years.

Q. Reporting

Any person holding a permit for a solvent cleaner subject to this rule shall submit an annual report to the Control District. The annual report shall contain the quarterly records required by Rule 321 Section P.1.b.1). The report shall be due March 1 for the previous calendar year.

R. Compliance Schedule

  1. The owner or operator of any solvent cleaning equipment in operation as of July 17, 1997 and subject to the requirements of this rule shall comply with the following:

    a. By August 16, 1997, be in full compliance with the applicable operating requirements of Rule 321 Sections D, E, and F.

    b. By January 13, 1998, be in full compliance with the applicable recordkeeping and reporting provisions of Rule 321 Sections P and Q.

    c. By July 17, 1998, be in full compliance with the applicable equipment requirements of Rule 321 Sections G, H, I, J. K, L, and M.

    d. Notwithstanding Rule 321 Section R.1.c, the provisions of Section G.8 shall take effect on July 17, 1997.

  2. This rule applies to any new or modified solvent cleaning equipment on July 17, 1997.