Printing operations emission calculations

This method may be used to develop an editable spreadsheet containing detailed emissions calculations for each printing operation at your facility. These instructions are used to calculate volatile organic compounds (VOCs) and individual and total hazardous air pollutants (HAPs) emissions. Potential emissions of other pollutants from the printing operation will also need to be included in the permit application (e.g., emissions from fuel combustion in a drying oven). Each step in your calculation(s) needs to be clear and easy to follow.

Include the following information in your spreadsheet

  • AQ Facility ID No. — Include your Air Quality (AQ) Facility identification (ID) Number (No.). This is the first eight digits of the permit number for all permits issued under the operating permit program. If your facility has never been issued a permit under this program, do not include it at this time.
  • AQ File No. — Include your AQ File Number, if known. This number can be found in the “cc” section of correspondence from the Minnesota Pollution Control Agency (MPCA). If you don't know or can't find this number, do not include it at this time.
  • Facility name — Include your facility name.
  • Emission unit or other identification number(s) — Include the identification number of the emission unit(s) (EU). Obtain this number from Form GI-05B or the appropriate form related to the permit you are applying for, or your existing permit.  
  • Stack/Vent designation number(s) — Fill in the designation number of the stack(s) or vent(s) through which the unit will exhaust into the atmosphere. Obtain these numbers from form GI-04 or the appropriate form related to the permit you are applying for, or your permit.
  • Control equipment — Include a description of the type of control equipment. Use the designation number of the control equipment (CE) through which the equipment will exhaust. Obtain this number from Form GI-05A, or the appropriate form related to the permit you are applying for, or your existing permit. If none, indicate no control equipment. If you are applying for a registration permit Option D, just provide a description of the control equipment.
  • Ovens, if applicable If oven(s) are used to dry or cure in the printing process, be sure to calculate emissions from the ovens as shown on the webpage for External Combustion Units. If the ovens use electric heat or UV curing, there would be no emissions.
  • Indicate the type of printing operation: Non-Heatset Web;  Heatset Web;  Flexographic; Sheetfed Lithographic; Gravure; Screen; Other (provide description).
  •  Formula/Equation — The formula and/or equation needs to be available in the spreadsheet cell for each calculation step (for example, Steps 2, 3, 5, 6, 7, and 8 below).
  • Operating limitations — Describe in detail any permit limits you plan to take to restrict your potential-to-emit (hours of operation, bottlenecks, etc. - see Proposing Synthetic Minor Permit Limits). Attach additional information, as needed. Describe the limiting factors, cite any rules that apply (e.g., Standards of Performance for Stationary Sources [NSPS, 40 CFR part pt. 60], Best Available Control Technology [BACT]). The associated limit must be used to calculate your potential-to-emit after permit limits in Step 11. If you used vendor certification or stack test data to limit your potential-to-emit, the factor you used will become your permit limit. Include all proposed limits on Form CD-01, and anywhere else as instructed in the application forms.
  • Additional Emissions Calculations for this unit(s) — If the emissions units described by these calculations include other types of emissions, calculations for those emissions should be included on a separate worksheet. For example, if this process/unit combusts fuel (ovens, thermal oxidizers, afterburners, etc.), include fuel combustion emissions; or if this process/unit uses clean-up solvents in addition to the process described by these emissions calculations, include emissions calculations for clean-up activities.

Ink/solvent/fountain solution information

For each ink, thinning solvent, cleaning solvent and fountain solution that could reasonably be used in this printing operation, provide the density, VOC content, solids content, each individual HAP content, and total HAPs content. To determine the density, VOC content, solids content, each individual HAP content, and total HAPs content, consult the (MSDS), VOC data sheet, or contact the manufacturer. If the MSDS gives a range (e.g., 10-15%), use the highest number in the range (e.g., 15%). This information should be provided in the spreadsheet (an example format is shown in Table 1 below). Use an abbreviation or code number for each material, if needed. Include all MSDSs  or other sources of ink, solvent or fountain solution information, in the application or submit the MSDSs electronically (on CD).

  • Ink/Solvent/Fountain Solution — List each ink, cleaning solvent, thinning solvent and fountain solution used.
  • Density — Indicate the density in lbs/gallon for each ink, solvent or fountain solution. This information can be obtained from the Material Safety Data Sheet (MSDS).
  • Determine VOC Content — For each ink, solvent or fountain solutionthat you use, indicate its VOC content in pounds per gallon (lbs/gallon). If the VOC content is listed in the MSDS in weight percent, calculate the lbs/gallon by weight using the following formula:   VOC content (lb/gallon) = [VOC content (weight %) ÷ 100] x ink density (lb/gallon)

If the MSDS or other source does not give the VOC content in lbs/gallon or in weight %, it may be given in volume %. In this case the VOC content of the coating in lbs/gallon can be calculated by using the following formula:  VOC content (lb/gallon) = [VOC content (volume %) ÷ 100]  x  VOC density (lb/gallon)

  • Determine Solids Content For each ink, solvent or fountain solution, indicate the solids content in lbs/gallon. If the solid content is not listed in pounds per gallon in the MSDS, use the following formula:  Solids content (lb/gallon)  =  [Solid content (weight %) ÷ 100]   x  ink density (lb/gallon)
  • Determine HAPs Content — For each ink, solvent or fountain solutionthat you use, indicate the content of each individual HAP and total HAPs in pounds per gallon (lbs/gallon).  If the HAP content is listed in the MSDS in weight percent, calculate the lbs/gallon by weight using the following formula:  HAP content (lb/gallon)  =  HAP content (weight %)  x  ink density (lb/gallon)

Table 1. Example format for Ink, Solvent or Fountain Solution information

Ink/Solvent/
Fountain Solution

Density (lb/gal)

VOC Content (lb/gal)

Solids Content (lb/gal)

Total HAPs Content (lb/gal)

HAP 1 Content
(lb/gal)

HAP 2 Content
(lb/gal)

Continue for each HAP

Ink A

 

 

 

 

 

 

 

Ink B

 

 

 

 

 

 

 

Fountain Solution A

 

 

 

 

 

 

 

Etc.

 

 

 

 

 

 

 

Emissions Calculations Instructions

Follow these steps for calculating your emissions from ink, solvent fountain solution, and cleaning solution usage for each printing operation at your facility. Generally, each column of your spreadsheet will correlate to each step indicated below, with the first column indicating the pollutant (VOC, each individual HAP and total HAPs). Additional columns can and should be included in the spreadsheet to indicate additional steps or information specific to your printing operation, such as the parameters for web presses or sheet-fed presses.

Ink Usage Emissions

Step 1. Pollutant - Include each of the following pollutants that your coating operation emits.

  • VOC = volatile organic compounds
  • HAPs = hazardous air pollutants – each individual hazardous air pollutant. See EPA's Web site for more information.
  • Total HAPs = All HAPs added together

Step 2.  Uncontrolled Emission Rate [lb/hr] - Use the following guidelines to calculate the maximum uncontrolled hourly emission rate of VOC, each individual HAP, and total HAPs from ink usage. Maximum hourly emissions must be calculated assuming maximum press speed (feet/minute for webs and sheets/hour for sheet fed presses), ink coverage, the VOC/HAP content in the ink, and web width for web presses. The maximum VOC/HAP content is based on the highest VOC/HAP content for all inks. For example, if Ink A has the highest VOC content and Ink B has the highest total HAPs content, use the value from Ink A for VOC emissions calculations and the value from Ink B for total HAPs emissions calculations. Any physical limitations (i.e., dryer capacity) in the process may be used in your calculation, but they must be clearly supported.

  • For Web presses:  E = S (ft/min) x W (ft) x C (lbs ink/ft2 web) x V (lb VOC/lb ink) ÷ D (lb ink/gal) x 60 (min/hour) x (1 – [R ÷ 100])
    • where:
      E  = potential emissions in pounds per hour
      S  = maximum web speed in feet per minute
      W  = maximum web width in feet
      C  = maximum ink coverage in pounds of ink per square foot (use manufacturer's information, historical records, or data from a similar press)
      V  = maximum VOC or HAP content of the ink in pounds per gallon
      D = density of the ink in pounds ink per gallon
      R  =  retention factor in web (generally, for VOCs, R = 95% for non-heatset lithographic presses and 20% for heatset web lithographic presses)
  • For Sheet-fed presses:   E = S (sheets/hour) x A (ft2) x C (lb ink/ft2 sheet) x V (lb VOC/lb ink) x (1 – [R ÷ 100])
    • where:
      E  = potential emissions in lbs/hour
      S  = maximum press speed in sheets/hour
      A  = maximum sheet area in square feet
      C  = maximum ink coverage in pounds of ink per square foot (use manufacturer's information, historical records, or data from a similar press)
      V  = maximum VOC content of the ink
      R  =  retention factor in web

Step 3. Maximum Uncontrolled Emissions – Maximum uncontrolled annual VOC, individual HAP and total HAPs  emissions may be calculated from the uncontrolled emission rate in lb/hr (for ink, fountain solution, or cleaning solution usage) by using the following equation. This is the ‘maximum unrestricted emissions’ in tons per year to be included in the middle column of item 3e on Form GI-07.

Max uncontrolled emissions (tons/year) = Uncontrolled emission rate (lb/hr) x 8760 (hours/year) x 1 ton/2000 lb

If you operate an offset lithographic printing press, you may account for the fact that some of the VOCs are retained in the substrate. For heatset equipment, assume 20% of the VOC is retained in the substrate. The equation for maximum uncontrolled emissions then becomes:

Maximum Uncontrolled Emissions (tpy) = Maximum Emission Rate (lb/hr)  x  8760/2000  x  0.8

For nonheatset equipment, assume 95% of the VOC is retained in the substrate. The equation for maximum uncontrolled emissions then becomes:

Maximum Uncontrolled Emissions (tpy) = Maximum Emission Rate (lb/hr)  x  8760/2000  x  0.05

Step 4. Pollution Control Efficiency, % -- Include the pollution control efficiency. The pollution control efficiency is the product of the capture efficiency and the destruction/collection efficiency indicated on Form GI-05A (or other similar form, depending on the type of permit you are applying for), or in your existing permit. Enter this number here and remember to include on Form CD-05 a plan to demonstrate and maintain the destruction/collection efficiency. The efficiency should be expressed for each pollutant. If there is no control for a particular pollutant, indicate “zero” as the control efficiency.

Step 5. Maximum Controlled Emissions -- Maximum controlled VOC emissions are calculated from the maximum uncontrolled emissions and the pollution control efficiency using the following equation. This is the controlled lb/hr required in the first column of item 3e on form GI-07.

Max Controlled Emissions (lb/hr) = Max Uncontrolled Emissions (lb/hr) x ([100 – pollution control efficiency] ÷ 100)

Step 6. Limited Controlled Emissions -- (Skip this step if applying for a Registration Permit Option D.) Limited Controlled Emissions are calculated by taking into account all limitations on operation of the source you are proposing to comply with in this application. These limitations include limits on hours of operation, limits on the VOC or HAP content of the materials used, limits on the rate or amount of materials used, etc. You start the calculation of Limited Controlled Emissions by recalculating the Maximum Emission Rate and taking into account the limits you propose. This is the limited controlled emissions in tons per year in the right column of item 3e on Form GI-07.

If an emission unit is subject to an emission limitation specified in 40 CFR pt. 60, 40 CFR pt. 61, 40 CFR pt. 63 or Minn. R. ch. 7011, you must take this into account in calculating the Limited Controlled Emissions. If you choose to propose to comply with more a stringent limit, you should state this clearly in item 11 and show the resulting allowed emissions in this calculation.

Step 7. Actual Uncontrolled Emissions --  Actual uncontrolled annual VOC emissions may be calculated from the uncontrolled emission rate in lbs/hr (for ink, fountain solution, or cleaning solution usage) by using the following equation:

Actual uncontrolled emissions (tons/year) = Uncontrolled emission rate (lb/hr) x H (hours/year) x 1 ton/2000 lb
where H = the number of hours operated per year.

  1. As an alternative, if you have records of actual VOC usage from the past two calendar years, you may use these historical records when completing step 6.
  2. If you operate an offset lithographic printing press, you may account for the fact that some of the VOCs are retained in the substrate.  For heatset equipment, assume 20% of the VOC is retained in the substrate. The equation for actual uncontrolled emissions of VOCs then becomes:

Actual uncontrolled emissions (tons/year)= Uncontrolled emission rate (lb/hr) x H x 0.0005 x 0.80

For nonheatset equipment, assume 95% of the VOC is retained in the substrate. The equation for actual uncontrolled emissions then becomes:

Actual uncontrolled emissions (tons per year) = Uncontrolled emission rate (lb/hr) x H x 0.0005 x 0.05

  1. Also for heatset equipment, you may make the following assumptions when calculating actual emissions:
    • You may assume a carry over of VOCs from ink to the dryer of 100%. This means that you may assume that all of the VOCs are emitted from the dryer, rather than at the press itself.
    • You may assume a carry over of VOCs from fountain solution to the dryer of 70% of alcohol substitutes. This means that if there are alcohol substitutes in your fountain solution, you may assume that 70% of the VOCs emitted from the fountain solution occur at the dryer, and 30% occur at the press.
    • You may assume a carry over of VOCs from cleaning solution used in an automatic blanket wash system of 40%,  when the vapor pressure is 10 mmHg or less at 20 °C. This means that if you operate an automatic blanket wash system, and the vapor pressure is 10 mmHg or less at 20 °C, then you may assume that 40% of the VOCs from the cleaning solution occur at the dryer, and 60% occur at the press. There is no carry over for any cleaning system other than an automatic blanket wash system.
  1. For both heatset and nonheatset equipment, when using cleaning solution with rags or wipes, you may assume that 50% of the VOCs from the cleaning solution remains in the rags or wipes. 50% of the VOC is then assumed to be emitted at the point of cleaning.
  2. For both heatset and non heatset equipment, if you dispose of, recycle, or reuse VOC-containing materials offsite, and you appropriately document the actions and quantities, you may take credit for that quantity of VOC that is not emitted at this particular location.

Step 8. Actual Emissions -- Actual controlled VOC emissions are calculated from the actual uncontrolled emissions and the pollution control efficiency using the following equation:

Actual controlled emissions (lb/hr) = Actual Uncontrolled Emissions (lb/hr) x ([100 – pollution control efficiency] ÷ 100)

Fountain Solution Emissions

Step 1. Pollutant - Include each of the following pollutants that your coating operation emits.

  • VOC = volatile organic compounds
  • HAPs = hazardous air pollutants – each individual hazardous air pollutant. See EPA's Web sitefor more information.
  • Total HAPs = All HAPs added together

Step 2. Fountain Solution Uncontrolled Emission Rate [lb/hr]  VOC emissions from fountain solutions are from alcohol added to the water in the fountain solution to decrease the surface tension of the water. The alcohol is assumed to be completely volatilized, so VOC emissions are equal to alcohol use. To calculate your VOC potential-to-emit from fountain solution, determine what your maximum possible usage of fountain solution could be in gallons per day. You may base this calculation on historical records or records from a similar press; however, make sure that you adjust these historical records to reflect the maximum capacity of your press. Remember that your estimate must reflect the maximum possible usage. Clearly indicate the maximum possible fountain solution usage in your spreadsheet.

Once you know the most fountain solution you could ever use in one day, you may calculate potential-to-emit as follows:

For Fountain Solution Usage:   E = U (gallons solution/day) x V (lb VOC/gallon solution) x 0.04167 (days/hour)

where:
E  = potential emissions in lbs/hr
U  = maximum possible fountain solution usage in gal/day
V  = maximum VOC content of fountain solution

Steps 3 through 8. To complete the calculations for fountain solution emissions, follow Steps 3 through 8 for Ink Usage Emissions Calculations Instructions (above) to calculate your emissions from fountain solution usage for each printing operation at your facility. Generally, each column of your spreadsheet will correlate to step indicated below. Additional columns can and should be included in the spreadsheet to indicate additional steps or information specific to your printing operation.

Cleaning Solution Usage Emissions

Step 1. Pollutant - Include each of the following pollutants that your coating operation emits.

  • VOC = volatile organic compounds
  • HAPs = hazardous air pollutants – each individual hazardous air pollutant. See EPA's Web site for more information.
  • Total HAPs = All HAPs added together

Step 2. Cleaning Solution Uncontrolled Emission Rate [lb/hr]  VOC emissions from cleaning solvents and cleaning solutions are calculated assuming the maximum VOC content of the cleaning solution, and assuming that all of the VOC is completely volatilized. The maximum amount of cleaning solution that would ever be used can be calculated based on historical records or records from a similar press, similar to the fountain solution calculation shown above. Adjust any historical data to reflect maximum production capacity. You must attach sheets showing your calculations. Remember that your estimate must reflect the maximum possible usage. Clearly indicate the maximum possible cleaning solution usage in your spreadsheet.

Steps 3 through 8. To complete the calculations for cleaning solution emissions, follow Steps 3 through 8 for Ink Usage Emissions Calculations Instructions (above) to calculate your emissions from cleaning solution usage for each printing operation at your facility. Generally, each column of your spreadsheet will correlate to each step indicated. Additional columns can and should be included in the spreadsheet to indicate additional steps or information specific to your printing operation.