UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX AIR DIVISION

Technical Support Document 

for

EPA’s Direct Final Rulemaking

for the

California State Implementation Plan

Santa Barbara County Air Pollution Control District, Rule 321, 

Solvent Cleaning Machines and Solvent Cleaning 

Prepared by: Adrianne Borgia

Reviewed by: Andrew Steckel

July 2011
2

Agency: Santa Barbara County Air Pollution Control District 

(SBAPCD)

SIP Approved Rule: Rule 321 – Solvent Cleaning Operations

Adopted – September 18, 1997

Submitted – March 10, 1998

EPA Approved – April 2, 1998 (64 FR 15922)

Subject of this TSD: Rule 321 – Solvent Cleaning Machines and Solvent 

Cleaning

Amended – September 20, 2010

Submitted – April 5, 2011

RULE SUMMARY -

Rule 321 establishes operating requirements for solvent cleaning machines and 

for solvent cleaning, stipulates the emission control system limits and lists the 

acceptable test methods. The rule also includes an Operating and Maintenance 

Plan, and Recordkeeping and Reporting requirements, and establishes a 

compliance schedule. The changes incorporated by the September 20, 2010

amendment are extensive. Some of the most significant changes include:

 

1. The title, Solvent Cleaning Operations, was changed to Solvent Cleaning 

Machines and Solvent Cleaning. In all cases, the term “degreaser” was 

replaced with “solvent cleaning machine”.

2. Section A, Applicability, now includes any person who owns, operates or 

uses any solvent cleaning machine or performs solvent cleaning during 

production, maintenance or servicing of parts, products, tools, machinery 

and equipment or in the general work area at any stationary source. 

3. Section B, Exemptions, was expanded to include the exemption of 

operations already subject to other district rules and several exemptions 

particularly targeting Raytheon’s systems. Exemptions for small containers 

have been removed.

4. Several definitions in section C, Definitions, were added to clarify terms 

used throughout the rule.

5. Section D, General Operating Requirements was expanded to include 

persons who own, operate or use solvent cleaning machines or performs 

solvent cleaning. Language was added to clarify ambiguous terminology 

and to address spills, filling, draining and the use of ventilation fans.

6. Requirements for operation of a system with a vapor zone was added to 

section E, Additional Operating Requirements for Batch Vapor Cleaning 

Machines and In-Line Vapor Cleaning Machines.

7. Added provisions for returning drained solvent to the container, 

augmented the solvent agitation to describe the acceptable motion and 

added requirements for ventilation fan usage to Section G, General 

Equipment Requirements for Solvent Cleaning Machines.

8. The addition of the 50 grams/liter Reactive Organic Compounds (ROC) 

limit was added to section H, Additional Equipment Requirements for 

Remote Reservoir Cold Cleaning Machines, section I, Additional 

Equipment Requirements for Batch Cold Cleaning Machines, and section 
3

K, Additional Equipment Requirements for In-Line Cold Cleaning 

Machines. 

9. The addition of the 50 grams/liter ROC limit and corresponding 

requirements was added to section L, Additional Equipment Requirements 

for In-Line Vapor Cleaning Machines.

10. Section M, Requirements – Solvent Cleaning, was added and includes 

solvent cleaning limit Table 1, Cleaning Devices and Methods and Solvent 

Cleaning of Spray Application Equipment. 

11. Section N, Emission Control System Requirements, was revised to include 

a compliance test and also to require that the emission control system 

result in emissions no greater than the limits allowed without controls. 

12. Section P, Test Methods, was revised to further elaborate on the emission 

control device efficiency testing method and required results.

13. The requirements for recordkeeping were expanded in Section R, 

Recordkeeping Requirements, to include usage, type of machine, solvent 

boiling point and, for emission control systems, the key operating 

parameters. 

14. Section T, Compliance Schedule, was updated to include current dates for 

compliance, including new dates for compliance by existing facilities. 

EPA EVALUATION - The following criteria were used to evaluate the submitted 

rule. 

1. Enforceability - The Bluebook (Issues Relating to VOC Regulation 

Cutpoints, Deficiencies, and Deviations, EPA, May 25, 1988) and the Little 

Bluebook (Guidance Document for Correcting Common VOC & Other Rule 

Deficiencies, EPA Region 9, August 21, 2001) were used to help evaluate 

compliance with the CAA §110(a)(2)(A) requirement for enforceability. 

2. Stringency – Rule 321 was partially evaluated against EPA’s Control 

Technique Guidelines (CTGs) titled, “Control of Volatile Organic Emissions 

from Solvent Metal Cleaning” (EPA-450/2-77-022, November 1977) and 

“Control Techniques Guidelines for Industrial Cleaning Solvents” (EPA453/R-06-001 September 2006), CARB’s RACT/BARCT guidance titled, 

“Organic Solvent Cleaning and Degreasing Operations” (July 18, 1991), 

and other state and local rules for this category were used to help evaluate 

the RACT requirements of CAA §182(b)(2). 

3. SIP Relaxation - We have evaluated this SIP revision to determine whether 

it would interfere with any applicable requirement concerning attainment 

and reasonable further progress (RFP) or any other applicable requirement 

of the Act (CAA §110(l)) or modify, in a nonattainment area, any SIPapproved control requirement in effect before November 15, 1990 (CAA 

§193).

Enforceability – SBAQMD’s Rule 321 specifies clear, unambiguous terminology 

and ROC limits. Each type of solvent cleaning machine has been addressed in 

terms of drainage, usage with high and low volatility solvents, when heat is 

applied, required freeboard height, etc. While the Emission Control System 
4

Requirements (section N) does not specify equipment, it does clearly indicate the 

required parameters. The Compliance Schedule (section T) clearly indicates the 

dates for full compliance for the various features of the rule. The requirement for 

submitting an Operation and Maintenance Plan (section Q) further strengthens 

this rule’s enforceability through procedures and recordkeeping. 

Stringency- SBAQMD’s Rule 321 is consistent with the EPA CTG: Industrial 

Cleaning Solvents and CARB’s Determination of Reasonably Available Control 

Technology (RACT) and Best Available Retrofit Control Technology (BARCT)

Organic Solvent Cleaning and Degreasing Operations. However, it does not have 

as stringent ROC levels as analogous rules in other districts including Sacramento 

Metropolitan AQMD rules 1122 and 1171 and San Joaquin Valley UAPCD rules 

4661, 4662 and 4663. SBAQMD is in attainment with the national ambient air 

quality standards (NAAQS) and, therefore, more stringent requirements are not 

required at this time under national requirements for RACT (CAA § 182(b) (2)) or 

RACM (CAA § 172(c) (1)). 

SIP Relaxation – SBAQMD’s Rule 321 now applies to any person who owns, 

operates or uses solvent cleaning machines or performs solvent cleaning 

operations which is a change from the 1992 version of the rule which only applies 

to any person who performs solvent cleaning. The rule has ROC limits which, 

compared to the current SIP rule that has no ROC limits, represents a 

strengthening of the rule. In sections E through L, specific requirements for 

machine operation have been added that also serve to strengthen the rule. The 

staff report indicates that the proposed revisions to Rule 321 will result in about 

0.5 tons per day of ROC emission reduction. 

Therefore, we propose to determine that our approval of the submittal would 

comply with CAA § 110(l), because the SIP, as revised to reflect the submitted 

revision, would provide for RFP and attainment of the NAAQS and this revision of 

the rule is more stringent than the rule previously approved into SIP. CAA § 193 

does not apply to this proposed action because SBAQMD is designated 

attainment for VOC’s.

RULE DEFICIENCIES - We have identified no deficiencies with Rule 321

sufficient for EPA to propose less than full approval. 

ADDITIONAL RECOMMENDATIONS FOR THE NEXT RULE REVISION - The 

following revisions are not currently the basis for rule disapproval, but are 

recommended for the next time the rule is amended. 

1. Consider reducing the solvent ROC limit to 25 grams/liter in the following 

subsections: B-13, B-15, G-3, H-7, I-7, J-11, K-6, L-11, M-2 and M-3. This

will maximize the emission reductions and provide consistency with other 

district rules such as those in South Coast AQMD and San Joaquin Valley 

APCD.
5

2. Please consider reducing the other limits in Table 1 of Section M according 

to the CARB recommendations that are currently in the South Coast AQMD 

Rules 1171 and 1124, and San Joaquin Valley APCD Rule 4663:

Solvent and Cleaning Activity ROC Limit

From To

g/l (lb/gal) g/l (lb/gal)

(a) Product Cleaning During Manufacturing 

Processes and Surface Preparation for 

Coating Application:

(i) General 50 (0.42) 25 (0.21)

(ii) Electrical Apparatus Components

& Electronic Components 900 (7.51) 100 (0.84)

(iii) Medical Devices & Pharmaceuticals 900 (7.51) 800 (6.7)

(b) Repair Cleaning and Maintenance Cleaning:

(i) General 50 (0.42) 25 (0.21)

(ii) Electrical Apparatus Components

& Electronic Components 900 (7.51) 100 (0.84)

(iii) Medical Devices & Pharmaceuticals:

(I) Tools, Equipment, & Machinery 900 (7.51) 800 (6.7)

(II) General Work Surfaces 900 (7.51) 600 (5.0)

(c) Cleaning of Coatings Application Equipment 950 (7.51) 25 (0.21)

(d) Cleaning of the Following Items and 

Equipment and their Components: 900 (7.51) 200 (1.68)

(i) Aerospace Vehicles;

(ii) Aerospace Vehicle Payloads and Satellites;

(iii) Aerospace Vehicle, Aerospace Vehicle Payload,

and Satellite:

(I) Transport Equipment (e.g., railcars, trucks,

trailers, forklifts, and containers), and

(II) Support Processing Equipment (e.g., clean

rooms, tools, payload fairing fixtures,

alignment jigs, fuel and oxidizer loading

carts and associated transfer lines).

3. For clarity, please change the phrase in subsection M-2 from “50 grams per 

liter of material...” to “50 grams of reactive organic compound per liter...” 

Also, subsection M-2-a would be more complete if the requirement to store 

wipes in containers was added. 

4. The following revisions to Section P should be incorporated to support the 

enforceability of this rule:

a. Subsection 5: Method 2G is in 40 CFR, Part 60, Appendix A-2.

b. Subsection 8: Method 18 is in 40 CFR, Part 60, Appendix A-6.

c. For consistency, add reference 40 CFR, Part 60, Appendix A-7, to 

Methods 25 and 25A indicated in subsection 8. 

d. The EPA approved version of ASMT E169, referenced in subsection 

7, is 1993. For consistency indicate as ASTM E169-93 (2004).
6

EPA ACTION - The rule fulfils the relevant CAA §110 requirements. EPA staff 

recommends a full approval of Rule 321 pursuant to CAA §110(k)(3) and §301(a). 

ATTACHMENTS -

1. SBAQMD Rule 321, Solvent Cleaning Machines and Solvent Cleaning, as 

submitted on April 5, 2011.

2. SCAQMD Rule 321, Solvent Cleaning Operations, as submitted on March

10, 1998.

REFERENCES –

1. “Control of Volatile Organic Emissions from Solvent Metal Cleaning,” EPA450/2-77-022, November 1977. 

http://www.epa.gov/ttn/naaqs/ozone/ctg_act/197711_voc_epa450_2-77-

022_solvent_metal_cleaning.pdf

2. Control Techniques Guidelines (CTG): Industrial Cleaning Solvents, EPA 

435/R-06-001, September, 2006.

http://www.epa.gov/ttn/naaqs/ozone/ctg_act/200609_voc_epa453_r-06-

001_ind_cleaning_solvents.pdf

3. “Guidance Document for Correcting Common VOC & Other Rule 

Deficiencies,” (a.k.a., Little Bluebook), EPA Region 9, August 21, 2001.

http://www.epa.gov/Region09/air/sips/littlebluebook2001.pdf

4. California Air Resources Board (CARB) Determination of Reasonable 

Available Control Technology (RACT) and Best Available Retrofit Control 

Technology (BARCT) for Organic Solvent Cleaning and Degreasing 

Operations July 18, 1991.