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The Five Ws and How of Delaware’s Proposed Revisions to the Limit of VOC Content in Solvent Cleaning Machines

Posted: September 21st, 2020

Authors: All4 Staff 

In May 2019, the Delaware Department of Natural Resources and Environmental Control (DNREC) proposed making numerous revisions to 7 DE Admin. Code 1124 Section 33.0 “Solvent Cleaning and Drying.”  These revisions will update control requirements that will reduce the maximum acceptable volatile organic compound (VOC) content for solvents used in cold degreasers.  This regulation is under development, but once implemented, has the potential to affect about 1,000 locations in Delaware.  Read on to learn more about what these regulatory modifications entail and whether or not your business will be affected.

Who will be affected by the proposed revisions to 7 DE Admin. Code 1124 Section 33.0?

Anyone who owns and operates a solvent cleaning machine in Delaware that contains any amount of VOC material will be subject to Section 33.0.  Previously, there was an applicability threshold of one liter of solvent, such that many facilities were not previously subject to the regulation.  Now, some of those facilities not previously subject to the regulation will need to comply with Section 33.0.  Anyone in Delaware who sells or imports solvents to be used in a solvent cleaning machine that contains any amount of VOC material will be subject to the revised Section 33.0, and will not be permitted to sell or offer for sale any solvent for use in a cold cleaning machine that contains more than 25 grams of VOC per liter.  Most revisions to this section will affect cold cleaning machines, also known as cold degreasers.  Cold cleaning machines include, but are not limited to, batch cold cleaners and conveyorized in-line cold cleaners.  A cold cleaning machine will be defined as “a solvent cleaning machine that contains or uses a non-boiling liquid solvent into which parts are placed to remove soils from the surfaces of the parts or to dry the parts.”  In Delaware, users of cold cleaning machines include vehicle sales and servicing locations, machine shops, and manufacturers of electronic, pharmaceutical, and aerospace equipment, just to name a few.

What revisions will be made to 7 DE Admin. Code 1124 Section 33.0?

The most notable proposed revisions to Section 33.0 will be the addition of VOC content restrictions for different types of cleaning machines.  The following subsections will be added regarding VOC content:

  1. 3.7 “VOC requirements for cold cleaning machines”
  2. 4.5 “VOC requirements for batch vapor cleaning machines”
  3. 5.4 “VOC requirements for in-line cleaning machines”
  4. 6.9 “VOC requirements for cleaning machines not having a solvent/air interface”
  5. 7.5 “VOC requirements for alternative standard”
  6. 11 “Test Methods”

Each of these sections either specifies a new VOC content restriction or that no VOC restriction will be implemented, depending on the type of cleaning machine.

Where applicable, the VOC content for cleaning solvents will be limited to 25 grams of VOC per liter.  There will be exceptions to this limit, which will be specified within the subsections listed above.  This limit will set a restriction on VOC content that was not explicitly specified in the previous version of the regulation.  Section 33.11 specifically outlines the methodology that is to be used to determine VOC content of materials subject to Section 33.0, as well as the operating parameters of the cleaning machine.

Additionally, there will be two new subsections added under Section 33.1 “Applicability.”  These subsections will set new criteria for the types of VOCs in solvent cleaning machines that will be subject to Section 33.0.  Proposed Section 33.1.5, for example, states that VOCs will not be separated into categories such as low-vapor pressure (LVP) chemical compounds or mixtures.  LVP-VOCs (usually 100% VOC) will not be allowed in cold cleaning machines under the proposed revisions.

There are also several proposed modifications to the definitions in Section 33.2 “Definitions.”  Cold cleaning machines and remote reservoir cold cleaning machines will be more specifically defined, and new definitions for idling mode, in-line cold cleaning machines, lip exhaust, and solvents will be added.

Section 33.3 “Standards for batch cold cleaning machines” will see the addition of three new subsections:,, and  These subsections will provide additional requirements for the control and maintenance of batch cold cleaning machines.

There will be other subsections added pertaining to monitoring, recordkeeping, and reporting requirements, such as 33.8.9, 33.9.6, and 33.10.3.  Notably, Section 33.10.3 now requires that the owner/operator of a solvent cleaning machine must obtain a signed document specifying the VOC content of the solvent as determined by the test methods outlined in the aforementioned Section 33.11.  This new requirement will require you to reach out to your solvent supplier.

Please reference the Draft of Regulation Revisions for a detailed overview of all proposed revisions to Section 33.0.

When will I have to comply with the proposed revisions?

Any new, modified, or reconstructed sources affected by this section must comply with the provisions upon start-up once the revisions become effective.  Existing sources will have at least one year to comply once the revisions become effective.  Per Section 33.1.3., your facility may have to submit a request to DNREC to amend your existing Title V Operating Permit or 7 DE Admin. Code 1102 permit.  ALL4 can help you determine the actions your facility may have to take.

Currently, the regulation is under development.  Public workshops were held on January 28 and January 30, 2020 in New Castle, DE and Dover, DE, respectively.  The next step for the development of the regulation is a public hearing, which has yet to be scheduled but is anticipated to take place sometime in the 4th quarter of 2020.

Where will the proposed revisions have jurisdiction?

Because the revisions are being proposed in 7 DE Admin. Code 1124 Section 33.0, the affected entities will be located in Delaware, but other federal or local regulations may also apply.  The revisions also apply to out-of-state suppliers selling cleaning solvents for use in Delaware.

Why are these proposed revisions taking place?

As presented in the January 28 and 30 public workshops, solvent use in cleaning machines produces VOC emissions, and VOCs contribute to smog.  The most recent amendment of Section 33.0 happened on November 1, 2001.  The hope is that the proposed revisions will reduce VOC emissions by one ton per day as well as decrease the formation of ground-level ozone in Delaware.  The draft of the regulation revisions is based on the Ozone Transport Commission (OTC) Model Rule for Solvent Degreasing 2012.  The OTC is an organization created under the Clean Air Act that develops solutions for ozone transport in the Northeast and Mid-Atlantic regions.  Other states, such as New York, have already taken action to implement aspects of the OTC Model Rule.

There will also be potential economic benefits to these revisions.  Lower emissions can result in lower annual emissions fees.  As presented during the January 28 and 30 public workshops, lower VOC solvents can have lower costs associated with disposal, and low-VOC parts cleaners can cost up to $282 less per year than higher-VOC parts cleaners.

How can I prepare for these regulatory changes?

There are several ways to prepare for compliance with these revisions as mentioned during the January 28 and 30 public workshops:

  1. Explore a water-based cleaning solution that contains no VOC.
  2. Test your equipment in order to find the solution or particular solvent that is appropriate for your unique process.
  3. Reach out to your solvent supplier or other solvent users to get their opinions.
  4. Research the South Coast Air Quality Management District (SCAQMD) list of certified clean air solvents to see what solutions are available for your particular process.
  5. Stay engaged in the regulation development process by regularly checking the DNREC website for updates on key events.


ALL4 can also help you determine if you will be subject to these new requirements.  Contact our team at info@all4inc.com should you have any questions or require additional information regarding the development of this regulation.


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