An Environmental Newsletter for the Industry

1st Quarter 2000


TITLE V Best Available Control Technology (BACT) UPDATE


The Multiple Air Toxics Exposure Study (MATES II) is a monitoring and evaluation study for the South Coast Basin, which focuses on urban toxics.  The study consists of (1) monitoring toxics (2) updating the SCAQMD’s toxic air contaminant inventory and (3) computer air quality modeling.  These elements were tied together to characterize the toxic risk in the South Coast Basin. 

SCAQMD staff collected approximately 4,500 samples from monitoring stations located in ten different sites.  A “micro scale study” was done for 14 additional communities and targeted residential areas located near sources of toxic emissions.

Over 30 toxic gas and particulate pollutants were measured.  The “carcinogenic risk” associated with these pollutants was computed based on California risk factors.  The carcinogenic risk is defined as the probability of a person contracting cancer over the course of a lifetime exposure (assumed to be 70 years) to the source of cancer-causing compounds.

Based on the results of the study, SCAQMD reported that the average carcinogenic risk in the basin is about 1,400 per million people.  In other words, out of one million people exposed to the toxics for seventy years, 1,400 are expected to contract cancer as a result of the exposure.  The number 1,400 is an average in a range of 1,120 to 1,740.  The sites with the greatest risk levels were in the south-central and east-central portions of Los Angeles County. 

Diesel particulate emissions accounted for about 70% of the risk levels, mobile sources emissions (benzene, butadiene and formaldehyde) accounted for 20% and the remaining 10% was attributable to emissions from the industry.

Community representatives expressed their concerns to the SCAQMD Governing Board about being exposed to toxics in their communities.  The residents asked that the District adopt stricter measures to reduce the carcinogenic risk.  Several industry representatives contended that the regulatory focus should be on mobile sources and not stationary sources, since the bulk of the toxic emissions were diesel particulate.  A spokesperson for the California Trucking industry noted that the trucking industry should not be subject to the unfair competition that more fleet rules would create.  After receiving public comments the Board received and filed the report.  Staff committed to further work with industry to address their concerns.   


SCAQMD has held several public workshops to present staff’s proposed streamlined record keeping requirements for Volatile Organic Compounds (VOC) emissions from coatings, inks, solvents, adhesives, and graphic arts sources.  Presently, the proposal involves (1) the creation of new VOC record keeping forms and industry specific forms

(2) general principles for alternative methods for determining VOC monthly usage (3) converting the current daily limits in SCAQMD rules to monthly limits and (4) converting daily permit limits to monthly limits.

In contrast to the current record keeping system the new system consists of three forms called VOC Listing, Production Log and Monthly Summary.  Staff has designed the three forms as shown below:

VOC listing:

The VOC listing form is considered the master list of all VOC containing materials used at a facility.  The product identification, manufacturer name, material category, VOC of coating, VOC of material, mixing ratio, vapor pressure and the type of substrate involved are all reported on this form.  The company is only required to amend the form whenever there are reformulations and product changes at the facility.

Production Log:

The production log is intended to be the supporting documentation for the facility’s VOC monthly emissions.  The amount of each material used at the facility must be recorded as it is used for production.  Facilities are required to maintain their purchase records on file to substantiate the accuracy of the production log.  While the log may be aggregated for all permit units (i.e. spray booths which are subject to facility-wide material usage or VOC emission limits), facilities should use caution when aggregating coatings as it may result in inability to make actual VOC determinations needed for purposes of offset exemptions and Best Available Control Technology applicability.

Monthly Summary:

The monthly VOC emissions are the essence of the monthly summary form.  It identifies the material, amount used, VOC content per volume of each material, emission factors and monthly VOC emissions.  Facilities not subject to daily limits can use the form to report emissions on a monthly basis.  Facilities wishing to convert their daily permit limits to monthly will need to submit change of condition applications.  The risk in doing so is that the new application may be considered a new source, which will trigger BACT requirements.  The SCAQMD is currently discussing this issue with the EPA, but has not reached a final policy decision.

Under the proposed requirements, facilities can employ alternative methodologies for determining monthly total usage.  In order to avail themselves of these provisions facilities must submit a proposal to the SCAQMD.  The alternative record keeping system must be:


v     Practically enforceable by AQMD compliance staff

v     Verifiable in a reasonable timeframe

v     Acceptable and sufficient in a court as valid evidence

v     Discouraging to non-compliance

v     Acceptable to CARB and EPA for compliance verification

After reviewing the applicant’s proposed alternative record keeping system and making the determination that it meets the criteria noted above, the SCAQMD would approve the alternative system and impose permit conditions to implement the necessary changes to the facility’s record keeping system.

The staff is also considering special provisions for supercompliant products (materials with a VOC content of less than 50 grams per liter). One of the issues under consideration is the concept of requiring limited or no records for supercompliant materials.  The preliminary proposal gives this flexibility to facilities, which are using supercompliant products exclusively.  There is also flexibility given to facilities, which are completely exempt from permitting.  Special forms have been developed for facilities which fall under Rule 219 (exempt from written permit) and those using supercompliant products. Currently, the provisions would not apply to facilities which use both conventional and supercompliant materials and those that are partially exempt.  These issues are still under consideration. 

The staff has solicited letters from the public on the proposal.  There is no formal comment period or deadline because this is not a rulemaking process.  The District has a special record keeping task force looking into implementation and policy issues.  The task force plans to make their recommendations to the Governing Board within the first quarter of 2000.


Proposition 65 – an initiative to address concerns about exposures to toxic chemicals – was approved by California voters in 1986.  The initiative became The Safe Drinking Water and Toxic Enforcement Act of 1986.  Prop 65 requires that the governor publish a list of chemicals that are known to the state to cause cancer, birth defects or other reproductive harm.  As of January 1999, over 660 chemicals appear on the list.  The list is updated at least once a year. The Office of Environmental Health Hazard Assessment (OEHHA) is the lead agency for Proposition 65.  Both Cal/EPA and OEHHA are responsible for ensuring that the public notice process is followed when placing chemicals on the list.

Chemicals on the list include but are not limited to dyes, solvents, pesticides, drugs, food additives, and process by-products.  The governor appoints two independent committees of scientists and health professionals to determine which chemicals will be placed on the list.  These committees are considered to be the “state’s qualified experts.”  Other agencies can also make determinations about listing chemicals if said agencies are considered “authoritative.”  The following agencies are designated as authoritative for Prop 65 purposes:

            For Carcinogens:      U.S. Environmental Protection Agency
                                                U.S. Food and Drug Administration
                                                National Institute for Occupational Safety and Health
National Toxicology Program
                                                International Agency for Research on Cancer                                       


            For Reproductive    U.S. Environmental Protection Agency
Toxicants:                 U.S. Food and Drug Administration
National Institute for Occupational Safety and Health
International Agency for Research on Cancer

Chemicals which are labeled by state or federal agencies as cancer causing can also be listed.

Companies with ten or more employees operating or selling products in California are subject to Prop 65 requirements.  Prop 65 prohibits businesses from knowingly discharging listed chemicals into sources of drinking water.  Businesses must also provide a “clear and reasonable” warning before knowingly and intentionally exposing anyone to the listed chemical.  The law requires businesses to give a warning unless a demonstration can be made that the exposure to the chemical poses no significant risk.

For carcinogens the “no significant risk” level is defined as no more than one excess case of cancer in 100,000 individuals exposed over a 70-year lifetime.  For reproductive toxicants, the no significant risk level is defined as the level of exposure which, even if multiplied by 1,000, will not produce birth defects or other reproductive harm.  That is, the level of exposure is below the “no observable effect level (NOEL),” divided by 1,000. The NOEL is the highest dose level which has not been associated with an observable reproductive harm in humans or test animals.

Since the Proposition 65 list must be updated every year, chemicals are frequently added to the list.  Sometimes chemicals are removed from the list. Effective December 1, 1999 two additional chemicals will be added pursuant to the administrative listing mechanism.  Methazole and Tributyltin Methacrylate will be considered known to the state to cause reproductive toxicity.

The costs of complying with Proposition 65 (i.e product reformulation, testing, providing warnings) offer an incentive for businesses to remove listed chemicals from their products.  The Office of Environmental Health Hazard Assessment credits Proposition 65 with providing “an effective mechanism for reducing certain exposures that may not have been adequately controlled under existing federal or state laws.”


Every three years, the South Coast Air Quality Management District (SCAQMD) adopts a plan (the AQMP) which outlines technical information relative to baseline emission inventories and control measures to achieve federal air quality standards.    Back in 1997, several environmental/community groups filed suit to compel enforcement of the emission control measures contained in the 1994 California Ozone State Implementation Plan (SIP).  On August 27, 1999, the U.S. District Court issued its intended decision on the litigation ordering the SCAQMD to implement 31 control measures from the 1994 Ozone SIP. Thus, the SCAQMD now proposes to amend the AQMP because in their view “the intervening years have brought new technology and new knowledge to bear on potential means of emissions control.”

The District has entered into a settlement agreement with the plaintiffs and adopted the revised plan at the monthly governing board meeting of December 10, 1999.  The amendment focuses on the ozone portion of the 1997 AQMP.  The proposal includes a revision of the 1997 plan stationary source control strategies and provides additional information on what SCAQMD considers “infeasible control measures.”  It does not change emission inventories.  The SCAQMD believes the amendments will address U.S. EPA’s proposed disapproval of the 1997 ozone SIP revision. At this point, emission reductions are proposed for:

. Solvent Cleaning Operations

. Architectural Coatings

. Industrial Coatings and Solvents

. Industrial Processes

. Large Solvent and Coating Sources

. Large Fugitive Sources

. Hydrogen Plant Process Vents

. Gasoline Dispensing Facilities

According to the staff’s emission reduction calculations, a total VOC reduction of 48.1 tons per day will be achieved by the year 2008.  Industry representatives have expressed concern that costly control measures will result in a negative socioeconomic impact. The staff faces the challenge of maintaining clean air goals while minimizing adverse effects on the local economy.


Title V of the 1990 federal Clean Air Act Amendments requires that the Environmental Protection Agency establish a national operating permit program.  Title V was intended to enhance air quality planning, emission controls, compliance and to improve existing emission inventories.  Under this program, EPA has authority to veto a local agency’s permit issuance.  There is also greater opportunity for federal and citizen enforcement and expanded public participation during the permitting process.

The SCAQMD Title V program has been administered under two phases: I and II.  Phase I was based on actual emissions.  Originally, just like in the phase I of the program, the applicability threshold for the phase II of the SCAQMD Title V program was to be based on facilities’ “Potential to emit.” The agency now plans to set the threshold for criteria pollutants at 5 tons/yr of actual emissions.  According to the AQMD Title V Group staff, the application packages are expected to be mailed to the phase II companies in June 2000.  Completed applications and forms will be due back at the AQMD within three months after receipt.  The application forms and the filing process for phase II companies are expected to be very similar to those of phase I applicants.

The AQMD is still negotiating with EPA about every aspect of the phase II of the program. Therefore, some of the information and dates stated above may be altered depending on the outcome of the SCAQMD/EPA discussions.

Best Available Control Technology (BACT) UPDATE

In accordance with the December 11, 1998 board policy to provide periodic BACT updates, District staff presented new BACT determinations/listings that were added to the guidelines Part B - Clearinghouse in the last quarter. Staff presented various new additions in the report to the Board, which was submitted as a “Receive and file” item.  The new BACT determinations involved the following source categories:

Source categories

BACT requirement


Nox emissions of 9 ppm or less, dry, at 3% oxygen

Circuit board photoresist developer

Low organic vapor pressure developing materials

Direct injection polystyrene manufacturing

Thermal oxidizer with a minimum of 98% VOC destruction efficiency

Dryer/oven - direct and indirect fired

NOx emissions at or below 30 ppm, dry, at 3% oxygen

Heater – refinery

NOx emissions at or below 7 ppm, dry, at 3% oxygen

Internal combustion engine; emergency compression ignition

NOx emissions at or below 6.9 grams/bhp-hr; PM10 emissions at or below 0.38 grams/bhp-hr

Internal combustion engine; emergency spark ignition

NOx emissions at or below 0.15 grams/bhp-hr; VOC emissions at or below 0.15 grams/bhp-hr, CO emissions at or below 0.60 grams/bhp-hr

Internal combustion engine; portable compression ignition

NOx emissions at or below 7.0 grams/bhp-hr; PM10 emissions at or below 0.38 grams/bhp-hr

Liquid transfer and handling; tank truck and/or rail car bulk loading, class A

Thermal oxidizer with overall efficiency of 95% VOC control

Lithographic or offset printing; non heatset

Regulation XI compliant materials

Mixer/blender; wet

Direct flame thermal oxidizer with overall efficiency of 95% VOC control

Rubber compounding; roll mill


Screen printing and drying

UV inks and small amount of water based inks

Spray booth

Regulation XI compliant materials

Storage; fixed roof

Thermal oxidizer with overall efficiency of 95% VOC control

The report also included a BACT/LAER determination for a boiler by the San Joaquin Valley Air Pollution Control District.  The boiler, located in Corcoran California, has NOx and CO emissions of 12 and 30 ppm respectively.  The emission rates were confirmed by source tests at 3% oxygen.