1 Final Staff Report with Appendices for 

 Revised Proposed Amendments to Rule 4682 

SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT 

FINAL STAFF REPORT 

Revised Proposed Amendments to Rule 4682 

(Polystyrene, Polyethylene, and Polypropylene Products Manufacturing) 

December 15, 2011 

Prepared by: Chelsea Gonzales, Air Quality Specialist 

 Anna Myers, Senior Air Quality Specialist 

 

Reviewed by: Dustin Brown, Senior Air Quality Engineer 

 Kathi Crump, Senior Air Quality Inspector 

 Jessi Fierro, Rule Development Supervisor 

Errol Villegas, Strategies and Incentives Manager 

 Samir Sheikh, Director of Strategies and Incentives 

I. SUMMARY 

The San Joaquin Valley Unified Air Pollution Control District’s (District) Governing Board 

(Board) last amended Rule 4682 (Polystyrene, Polyethylene, and Polypropylene Products 

Manufacturing) on September 20, 2007, after the Ozone Rate of Progress Plan included 

this rule amendment as a feasible measure, as suggested by the Environmental 

Protection Agency (EPA). The Rule 4682 amendment was designed to reduce 

emissions of volatile organic compounds (VOC), trichlorofluoromethane (CFC-11), and 

dichlorofluoromethane from manufacturing polymeric foam and foam products by 

specifying VOC emission limits and emission control devices. The District submitted the 

2007 amended rule to the California Air Resources Board (ARB) for forwarding to the 

EPA as an amendment to the State Implementation Plan (SIP) in 2008. 

Upon evaluation of Rule 4682, EPA proposed a limited approval and limited disapproval 

of the rule as an amendment to the District portion of the SIP (Revisions to the 

California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control 

District, 2011, 41745-41747). A copy of the Federal Register and the Technical Support 

Document (EPA’s Analysis of San Joaquin Valley Air Pollution Control District’s Rule 

4682, Polystyrene, Polyethylene, and Polypropylene Products Manufacturing [TSD], 

2011) publication is included as Appendix C of this final staff report. 

Pursuant to §179 of the Clean Air Act (CAA), unless the rule has been updated and 

approved into the SIP within 18 months after the limited disapproval, one or more 

sanctions shall be imposed until EPA determines that the State has come into compliance. 
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The purpose of this project is to update Rule 4682 to address EPA comments, satisfy 

CAA requirements, and end the sanctions clock. 

This rule addresses VOC emissions from a source category that is relatively small. 

VOC emissions reductions are generally far less important to the Valley’s long-term 

attainment goals than are NOx emissions reductions. As such, the Valley’s attainment 

strategies generally emphasize NOx reductions. The District will continue to seek as 

much VOC reductions as expeditiously practical, technologically feasible, and as 

economically reasonable as determined by the Governing Board. 

II. RULE DEVELOPMENT PROCESS 

This rule development process is principally focused on ensuring that Rule 4682 meets 

requirements for Reasonably Available Control Technology (RACT). The District has 

conducted a thorough analysis and is proposing amendments that are expected to 

result in full EPA approval of Rule 4682. The District proposes to make some 

administrative changes to the rule and to bifurcate the VOC limits of Section 5.2.1. 

Based on the District’s evaluation of sources subject to Rule 4682, this rule amendment 

is not expected to impact Valley facilities, given their current methods of compliance. 

As part of the rule development process, District staff hosted a public workshop on 

November 17, 2011. Staff solicited comments from the public, stakeholders, ARB, and 

EPA at the workshop and during a 12 day commenting period after the workshop. 

Comments received during this period were evaluated and incorporated into the rule as 

appropriate. 

Per the District’s new socioeconomic policy, adopted by the District Governing Board in 

October 2011, staff solicited feedback from stakeholders at the November 17th

workshop on trade organizations effected by the rule amendment. The Expandable 

Polystyrene (EPS) Air Quality Coalition has been identified as an effected trade 

organization as a result of this effort. 

The revised proposed rule and final draft staff report will be published and made 

available to affected sources and interested parties prior to a public hearing of the 

Board to consider adoption of the proposed rule amendments. Proposed amendments 

are scheduled to be presented to the Board during the public hearing on December 15, 

2011. 

III. BACKGROUND 

The two major categories of processes regulated in Rule 4682 are extrusion foam 

production and expansion foam production. Each process employs a blowing agent to 
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create spaces in the plastic structure and to produce a strong, but lightweight material 

with good thermal insolating properties. The key difference between the two processes 

is that the expansion foam production facilities create most of their products in batches 

and are able to determine daily emissions, whereas the extrusion facilities create all 

final products through a continuous process where daily emissions are very difficult to 

determine. The following sections will elaborate on extrusion, expandable polystyrene 

(EPS) molding, and the control technologies available to offset VOC emissions from 

these production processes. 

A. Extrusion 

Extrusion is a multi-day process that begins with plastic beads that typically contain little 

or no VOC content. A VOC blowing agent is added to the plastic beads in the 

manufacturing process to create the final product. The extrusion process is detailed as 

follows: 

1. The plastic beads, which typically contain little or no VOC content, are delivered 

in bulk and pneumatically transferred to storage silos until needed. 

2. The beads are moved from the storage silos and heated with a VOC-containing 

blowing agent, under pressure in an auger. 

3. As the materials mix, the blowing agent expands and forms bubbles in the plastic 

which is then extruded through a forming die to form a continuous foam sheet of 

a desired thickness. 

4. The sheet of foam is cooled, cut to the needed width, and moved to a storage 

area for aging for 3-7 days because the cell structures within the foam need to 

stabilize for manufacturing purposes. 

5. After aging, the foam sheets are moved to the thermoforming machines. These 

machines use a combination of heat and pressure to produce a variety of 

products. 

6. The completed products are packaged and sent to storage areas to continue the 

off-gassing of blowing agents and to await shipping for a minimum of 4 days. 

7. Excess material that is trimmed off during manufacturing is recovered and 

recycled either on-site or off-site at the bead manufacturing facility. 

Many aspects of the manufacturing operation are variable. This includes: 

• Property fluctuations of the liquids and gases used depending on the prevailing 

temperature and humidity in the manufacturing plant 
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• Property variations between the colored dyes utilized 

• The variety of products and product sizes manufactured, requiring different levels 

of blowing agent 

• Inconsistent amounts of recycled material affecting the changeability in the 

amount of virgin material needed 

Since the complete extrusion process is extensive, VOC emissions come from many 

phases, including: 

• Extrusion and sheet forming processes 

• Aging of the rolls 

• Thermoforming 

• Finished goods storage 

• Continual VOC release from the residual blowing agent contained in the air 

pockets 

The variability of process times combined with multiple emissions sources contributes to 

the complexity of determining emissions. 

B. Expandable Polystyrene Molding 

In contrast to extrusion, the EPS molding process uses raw beads that already contain 

the needed blowing agent. In certain cases where the EPS facilities utilize continuous 

expanders, the complete production process can extend beyond 24 hours. The EPS 

molding process is detailed as follows: 

1. Prior to molding, the beads are pre-expanded using heat to slightly expand the 

blowing agent and puff the beads. 

2. Beads are cooled and stored in emission-controlled containers for intermediate 

aging and stabilization. 

3. Products are molded: 

a. The mold is filled with puffed beads 

b. The beads are heated to complete their expansion

c. The molded product is released 

d. Sometimes, depending on the product, a vacuum is used to better fill the 

mold 

4. Finished products may require trimming to reduce flashing or seam material that 

escapes at mold joints or pour points. Any waste materials are collected for 

recycling. 
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5. Finished materials are packaged and moved to storage until shipping. 

There are three types of EPS molding encompassed within the above process: 

• Block molders produce large blocks of foam which are cut into sheets such as 

building insulation, or other desired shapes after molding. There are currently no 

block molders in the Valley. 

• Shape molders make custom foam shapes such as grape shipping boxes or 

packing inserts to protect electronic equipment during shipment. Three of the 

four EPS facilities subject to Rule 4682 are shape molders. 

• Cup molders make cups, bowls, and other similar foam containers. There is 

currently only one cup molder in the Valley. 

In all three types of molding, the two primary phases that allow for emissions losses are 

during pre-expansion and molding steps; in both steps, steam is used to vaporize the 

blowing agent and puff the bead. However, methods for capturing these emissions 

differ based on the type of molding facility. 

Cup molding operators have methods for capturing emissions from the pre-expansion 

step, but to date they have not been able to find a way to capture the molding 

emissions. Cup molders are unique in that there is no vacuum step in the cup molding 

process. Facilities do not have the option of tying into the vacuum line to collect 

emissions directly off the machine. Using individual hoods to enclose the manufacturing 

operation is not a feasible option because they would interfere with the air flow required 

for product handling, which is critical to product efficiency. It is not possible to capture 

the cup molding emissions unless the facility were to enclose the entire manufacturing 

operation using a permanent total enclosure (PTE), which is a costly alternative, and 

may also interfere with the air required for product handling. 

C. Control Technologies 

There are three control systems available for facilitating emissions reductions for 

extrusion and EPS facilities. The District researched the applicability of each option to 

Valley businesses. 

1. Thermal Oxidation (Incineration): A thermal oxidizer destroys VOCs through 

combustion. The systems can be divided into two categories: 

• Recuperative systems increase fuel efficiency by the use of a gas pre-heating 

section and a heat recovery section to capture waste heat to preheat incoming 

air. PM10 and VOC conversion efficiencies range from 97% to 99.9%. 
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• Regenerative systems use a ceramic heat-exchange bed to preheat processed 

air to within 5% of the oxidation temperature. PM 10 and VOC conversion 

efficiencies range from 95% to 99%. 

Four extrusion and three EPS shape molding facilities in the Valley utilize 

regenerative thermal oxidizer (RTO) systems. However, the cost per ton of VOC 

removed in RTO systems is high due to the large exhaust flow rates and low VOC 

concentrations of the exhaust stream so this is not a viable option for all companies. 

For the 2007 rule amendment, the District estimated that the installation of a RTO 

would cost each of the three EPS shape molding facilities $27,235/ton of VOC 

emissions reductions and $24,958/ton of reductions for the EPS cup molding facility. 

However, although it was a costly endeavor, in an effort to reduce emissions the 

shape molders still went through with the addition of this control technology. 

2. Adsorption Vapor Recovery: This is accomplished by passing the VOC-laden gas 

through beds containing adsorbents that have a high surface area to weight ratio. 

Adsorption of the hydrocarbon molecules proceeds until the available surface area is 

filled or saturated with VOC molecules. The VOC molecules are retained until the 

regeneration step, or disposal of the spent adsorbent. 

There are three basic types of adsorption systems available: 

• Pressure Swing Regenerated Systems and Thermally Regenerated 

Systems regenerate the adsorbent in-situ for reuse. 

• Canister systems require removal of the adsorbent to another site for 

regeneration. While canister systems can be purchased directly from the 

manufacturer, the high volume of the exhaust stream and the amount of 

emissions to be controlled make this less practical than the other two 

systems. 

Currently, none of the facilities subject to Rule 4682 use these systems. The main 

reasons are due to high costs and better results from other systems and 

technologies. As previously discussed, most extrusion facilities in the Valley use 

RTOs as their control technology of choice. For EPS cup molding facilities, this is 

not a viable option because, as previously stated, they cannot capture the emissions 

from molding unless PTE is employed. If the VOC gas cannot be contained, then it 

cannot be sent through adsorbent beds to eliminate emissions. 

3. Boilers: Boilers can be used as a VOC control technology because they provide 

necessary process steam for the operation and control of VOC emissions. Boilers 

can be modified or designed to burn the collected vapors via direct combustion and 

decrease the boiler’s fuel consumption. Boilers at these types of facilities have 

demonstrated VOC destruction efficiencies of at least 95% by weight. Multiple valley 
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facilities transport pentane emissions from the raw bead handling system and preexpansion phase to a boiler system that reduces at least 95% of the pentane. 

RTOS are the most effective control systems for handling VOC emissions; however 

issues of cost effectiveness can halt their installation. While adsorption vapor recovery 

systems are effective, implementation of these systems comes secondary to RTOs and 

boilers for Valley facilities. Lastly, while boilers serve as the most cost-effective solution 

extrusion and EPS facilities cannot solely rely on these systems to reach compliance 

goals. 

IV. DISCUSSION 

EPA analyzed District Rule 4682 and commented that requirements should be 

strengthened to implement Reasonably Available Control Technology (RACT) and 

allow EPA to approve the rule into the SIP. 

The following is a summary of EPA comments with the District’s responses; refer to 

Appendix C to review the TSD in its entirety. 

A. Section 3.0 – Definitions 

To improve rule clarity of Section 5.0, the following definitions were added to the 

rule: 

Expandable Polystyrene Molding: A series of processes where expandable 

polystyrene beads, which are polystyrene resin particles impregnated with 

blowing agent, undergo expansion, aging and then cup, shape, or block 

molding to form a low-density foam product. During expansion, the beads are 

expanded to the appropriate desired density by exposure to steam or hot air 

in a pre-expander. During aging, the expanded beads (or pre-puff) are 

transferred to storage silos or mesh bags to stabilize and dry. During molding, 

the aged pre-puff is exposed to heat in a closed mold that causes the beads 

to soften, re-expand, and fuse together to form the shaped product. 

Extrusion: the process in which a plastic resin is melted in an extruder and 

continuously forced through a die opening shaped like the finished product. 

As it leaves the die opening, the extruded plastic melt partially expands and is 

then drawn by a puller through forming equipment that sizes, cools, and cuts 

the product to length or winds it into a roll. With extruded foam products, 

blowing agent is injected under pressure directly into the extruder where it 

mixes with the plastic melt. 
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Operator: includes but is not limited to any person who owns, leases, 

supervises, or operates a facility and/or equipment. 

Total Product Emissions: includes emissions from the manufacturing 

operation, after controls, plus the residual blowing agent in the finished 

product. 

The definitions of expandable polystyrene molding and extrusion were derived from the 

Bay Area Air Quality Management District (Bay Area) Rule 8-52 and the definition of 

operator was taken from District Rule 4566. For clarity purposes, the definition of total 

product emissions was moved from Section 5.2.1 to the definitions section of the 

revised proposed rule. 

B. Section 5.0 – Requirements 

Section 5.1 

After reviewing the previously amended rule, the District proposes to delete Section 5.1 

since the requirements of the section are no longer valid. 

Section 5.2.1 

EPA Comment: Section 5.2.1 establishes an emission limit of 2.4 pounds of VOC per 

100 pounds of total material processed, calculated over a monthly period. EPA 

generally cannot approve compliance periods exceeding 24 hours unless specific 

criteria are met. These criteria are discussed in the O’Connor memo1

, which is included 

as Appendix C of the staff report. The O’Connor memo states that longer averaging 

times may be permitted under certain conditions. The 2007 staff report for Rule 4682 

does not provide a clear explanation of why daily emissions cannot be determined. 

Additionally, South Coast Air Quality Management District (SCAQMD) Rule 1175 and 

Maricopa County (Arizona) Rule 358 contain similar limits without monthly averaging. 

The District needs to demonstrate why an emission limit that appears to have been 

achieved in practice by existing operations in other districts cannot be met on a daily 

basis in the District. If needed, the District could consider creating distinct limits based 

on the type of facility. 

District Response: To address EPA concerns, District staff reviewed the facilities 

subject to Rule 4682 and identified three affected categories: extrusion facilities, 

expandable polystyrene (EPS) cup molding facilities, and EPS shape molding facilities. 

The production processes of extrusion and EPS facilities differ significantly and thus 

required separate evaluations of the effects of a daily limit. To address differences in 

these operations, District staff proposes to bifurcate the requirements for extrusion and 

EPS facilities. These would become effective January 1, 2013. As explained in detail 

 

1

 O’Connor, John. (January 1984). Averaging Times for Compliance with VOC Emissions 

Limits—SIP Revision Policy. 
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below, Section 5.2.2 (which will apply to extrusion facilities) proposes to maintain the 

2.4 pounds of VOC per 100 pounds of throughput limit, calculated monthly and Section 

5.2.3 (for EPS facilities), proposes a daily limit of 3.4 pounds of VOC per 100 pounds of 

throughput while maintaining the current monthly limit of 2.4 pounds of VOC per 100 

pounds of throughput. 

Extrusion Facilities 

As explained in the TSD, longer averaging times may be permitted under certain 

conditions in cases where daily emissions cannot be determined. Section 5.2.2 

maintains existing monthly standards for extrusion facilities because the District 

determined that some extrusion facilities would be unable to comply with the daily limit. 

The O’Connor memo provides five criteria that must be fulfilled in order to maintain the 

monthly averaging time for compliance. The five conditions and the District analysis of 

existing Rule 4682 are as follows. 

1. The VOC limits specified in an enforceable form with appropriate compliance 

dates. 

Rule 4682 is intended to reduce VOC emissions from manufacturing polymeric foam 

and foam products by specifying VOC emission limits and approved emission control 

devices. The existing rule contains a volatile organic compound (VOC) product 

emissions limit of 2.4 pounds per 100 pounds of total material processed. The 

product emissions include emissions from the manufacturing operation, after 

controls, and the residual blowing agent in the finished product. Proposed 

amendments will bifurcate Section 5.2.1 of the rule to Section 5.2.2 for extrusion and 

Section 5.2.3 for expansion facilities. Sections 5.2.4 - 5.2.7 identify four other 

methods for compliance via emission control systems or technologies. Proposed 

amendments will have a compliance deadline of January 1, 2013. Therefore, Rule 

4682 does contain VOC limits in an enforceable form with appropriate compliance 

dates. 

2. A description of the affected processes and associated historical production 

and operating rates. 

The length of the extrusion process and previously mentioned manufacturing 

variations foster inconsistencies in process time, the amount of materials used, and 

subsequent VOC emissions. The inherent lack of predictability in these conditions 

creates difficulties for extruders to accurately estimate emissions on a daily basis. 

There are a variety of products needed from these facilities that require beads with a 

higher VOC content. One key company’s biggest account is producing meat trays 

for two large poultry companies. However, meat trays require increased levels of 

blowing agent in order to improve durability and leak-resistance. This increases total 
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product emissions from the facility and the likelihood of exceeding the VOC limit. In 

order to comply daily, the company would have to eliminate production of high VOC 

products such as these and take a significant cut in profits. The companies currently 

order 70% of their foam trays from the business, which constitutes about 40% of 

total profits. A 40% loss would result in company cutbacks and job loss. In addition, 

the companies would start ordering out of state because of quality standards that 

cannot be met anywhere else in California. This would potentially increase 

transportation emissions to the Valley and make it questionable as to whether the 

reduced production of meat trays would create overall emissions reductions. 

Also, demand changes quickly for extrusion facilities based on customer needs. In 

the past, affected businesses have received last minute requests from their major 

accounts. For example, when a food packaging processer got chickens that were 

too big for the current containers, they requested an emergency shipment of large 

containers. The company’s flexibility to meet the ever-changing customer demands 

contributed towards a stronger business relationship and helped them receive larger 

order requests in the future. However, these production variations make it difficult 

for the facilities to comply on a daily basis. If forced to take daily emissions 

calculations, extruders would have to turn down last minute requests from their large 

accounts and risk losing a significant amount of business. 

3. A description of the control techniques to be applied to the affected processes 

such as low solvent and waterborne coating; technology and/or add-on 

controls. 

The District considered the feasibility of facilities complying via 5.2.2 to switch their 

compliance method to one of the other four options. 

Section 5.2.4 allows for compliance by the use of a non-VOC blowing agent; 

however, this option is not feasible for extrusion facilities. The affected companies 

currently use methyl formate (non-VOC) as a blowing agent for their plastic foam 

products manufacturing process. This is a costly effort for the companies because 

the use of non-VOC blowing agents requires reconstruction and modification of the 

polystyrene extrusion lines. The companies have recently proposed to increase the 

use of methyl formate to further reduce emissions. While the agent can be used for 

a good portion of products, it cannot be used to produce everything due to durability 

requirements of certain items like meat trays. Thus, the second option is unavailable 

to them. 

The next three options (Sections 5.2.5 -5.2.7) require that at minimum, an emission 

capture system must collect 90% of emissions by weight and shall reduce emissions 

from the capture system at 95% by weight. All affected extrusion facilities currently 

use extensive capture and control systems, but it is impossible for them to reach 
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90% emission capture efficiency. One business provides a good example of how a 

thorough control system falls short of meeting this compliance option. 

The company currently controls the VOC emissions that result from the extrusion 

operations, thermoforming lines, and scrap reclaim systems with a 5.78 MMBtu/hr 

regenerative thermal oxidizer (RTO). The overall facility VOC capture efficiency from 

the extruders, thermoformers, grinders, reclaim extruders, fluff silos, and roll storage 

area is a minimum of 77.5%, as mandated by their current permit. The RTO controls 

the VOC emissions that are captured with a minimum destruction efficiency of 95%. 

However, the facility has trouble going too far beyond the minimum capture 

efficiency level due to numerous manufacturing emission sources and the longevity 

of the extrusion process. While the company achieves significant emissions 

reductions, their system cannot meet the minimum standards of the other three 

options. 

The other extrusion facilities also employ RTO’s with similar configurations. 

Likewise, their systems achieve excellent destruction efficiency, but find it impossible 

to meet the 90% capture efficiency. Compliance option 1 in Section 5.2.2 remains 

the only option for these facilities that have already fully extended company funds for 

efficient control technologies. 

4. The nature of the emission control program whether a bubble, a regulation 

change, a compliance schedule, or some other form of alternative control 

program. 

This control measure was listed in the Ozone Rate of Progress Plan as a feasible 

measure suggested by the EPA. Rule 4682 is intended to reduce VOC emissions 

from manufacturing polymeric foam and foam products by specifying VOC emission 

limits or emission control devices. Emission reductions requirements must be 

technologically and economically feasible for Valley sources. This is why the District 

provides facilities subject to Rule 4682 with multiple compliance options. 

However, variable circumstances coupled with a long production period create a 

unique disadvantage for extrusion facilities in the Valley. Despite the funding and 

construction of thorough control systems, these facilities can only achieve 

compliance with option 5.2.2. Furthermore, these same difficulties preventing 

compliance through another route make compliance with 5.2.2 next to impossible if 

daily limits are mandated. 

5. The method of record keeping and reporting to be employed to demonstrate 

compliance with the new emission limit requirement and to support the 

showing that the emission limit is consistent with RFP and the demonstration 

of attainment. 
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The recordkeeping verifying the 30-day average emissions limit is consistent with 

the District’s RFP (Reasonable Further Progress) and attainment demonstrations as 

adopted in District attainment plans, such as the 2007 Ozone Plan. For ozone RFP 

and attainment demonstrations, the District utilizes “summer average” (April through 

September) emissions expressed as an average tons per day. In any emissions 

category, there will be some fluctuation from day to day, but the emissions for the 

RFP and attainment calculations are meant to represent average days. The 30-day 

averaging in the Rule 4682 limit still allows for an average tons per day reduction 

contributing to the District’s RFP and attainment demonstrations. 

Furthermore, the Valley’s nonattainment of the 8-hour ozone standard is 

characterized by persistent ozone concentrations, multi-day episodes of pollutant 

build-up, and many exceedance days each year. Under these circumstances, Rule 

4682’s 30-day averaging is sufficient to contribute to improvements in the Valley’s 

ozone concentrations. In contrast, in an area experiencing just a few days of peak 

ozone concentrations each year, a 24-hour limit could be essential to eliminating 

these peaks. This is not the case in the Valley for ozone. 

Implementing stringent recordkeeping guidelines is essential to the effective 

execution of Rule 4682. The District largely utilized EPA and ARB standards as the 

guideline for this section. 

The four requirements of recordkeeping are as follows: 

• All applicable facilities (including exempt facilities) must maintain at least monthly 

totals of the material processed, equipment used, and type of blowing agent 

used. 

• All facilities using an emissions control system to comply must maintain daily 

records of key operational characteristics to ensure compliance with the VOC 

emission requirements such as temperature, pressure, and flowrates. 

• Facilities choosing to comply via Section 5.2.1 must maintain records to show 

compliance with that section and shall calculate the daily average VOC 

emissions once a month. 

• Facilities must keep and maintain records for at least five years. 

Extrusion facilities consistently abide by the aforementioned guidelines and provide 

substantial documentation to prove monthly compliance. However, due to the 

necessity of the multi-day production process, anything shorter than monthly 

averaging will significantly deter the fluidity of their recordkeeping protocol. Most 

extrusion facilities have one Standard Accounting Program (SAP) to account for their 

processes continuously. This allows facilities to back calculate the monthly average 
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VOC emissions based on the usage of materials. It is a 10 hour process to 

complete the emissions calculations. This makes it impossible to conduct analyses 

daily with the current system. Furthermore, it is very costly for extrusion facilities to 

install a new recordkeeping system. Several devices would be needed in order to 

capture emissions data throughout the extrusion process on a daily basis and 

process the data into a new data acquisition system. Table-1 lists these devices and 

related costs for installation. 

TABLE – 1: Recordkeeping Equipment Needed for Daily Limits 

Item Item Cost Range of Items 

Needed 

Average Facility 

Cost (low estimate)

Tank Level Sensor $5,000 2 - 4 $10,000 

Fluff Silo Load Cells $75,000 6 - 11 $450,000 

Virgin/RPP Silo Level $20,000 9 - 14 $180,000 

Extruder Hopper 

Loader $57,655 4 - 10 $230,620 

Data Acquisition 

System $25,000 1 $25,000 

Micro Motion Flow 

Meter $20,000 4 - 5 $80,000 

Reclaim weigh scale $215,000 1 $215,000 

Average Total Cost $1,190,620 

Installing the equipment and new accounting system necessary for daily 

recordkeeping would result in an average facility cost of at least $1,190,620. These 

costs would be in addition to the $2.5 million dollars that affected businesses spent 

to install RTOs and comply with the 2007 rule revision. 

Even with the installation of a new system, daily instantaneous numbers would not 

accurately represent emissions for extruders. This number is never consistent 

because the company never makes and stores the same things at the same times. 

Also, facilities do not make the various containers at the same ratios on a constant 

basis. The extrusion process variations, previously mentioned, further complicate a 

daily recordkeeping process. Daily recordkeeping is neither feasible through current 

systems nor cost-effective in another system. 

As discussed above, the situation of the Valley’s extrusion facilities meet the five criteria 

of EPA’s O’Connor memo. The inherent multi-day production process necessitates 

monthly averaging for fluidity of recordkeeping, and daily instantaneous numbers would 

not accurately represent emissions. Also, these facilities produce a very wide range of 

products, some of which require beads with a higher VOC content. Demand can 

change quickly for extrusion facilities based on customer needs. Together, these 
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variable circumstances and long production periods create a unique disadvantage for 

Valley extrusion facilities. The District concludes that the 30-day averaging limit 

represents RACT for extrusion facilities based on these factors and the O’Connor 

analysis. The District will submit this analysis and documentation to EPA and request 

their approval of monthly averaging for extrusion as RACT. 

Expandable Polystyrene Facilities 

Cup Molding Facilities 

The District is proposing to add a daily VOC limit for EPS cup molding facilities. There 

is currently one EPS cup molding facility in the Valley complying with Section 5.2.1 

requirements. 

The affected facility currently calculates manufacturing emissions daily for their permit 

requirements, so extending the daily calculations to total product emissions will only 

create minor administrative changes. The District incorporated a new requirement into 

proposed Section 5.5 “Compliance Plan” to account for the new daily limit. Operators 

complying with Section 5.2.3 will be required to submit a Compliance Plan, which 

includes all necessary information to show the proposed method of compliance as of 

January 1, 2013. 

The District considered the daily limits imposed by other air districts. South Coast has a 

limit of 2.4 pounds of VOC per 100 pounds of throughput in their Rule 1175 and Bay 

Area has a limit of 2.8 pounds for EPS cup molding operations and 2.7 pounds for EPS 

shape and block molding operations in their Rule 8-52. However, these limits would 

push the affected Valley company out of compliance when producing certain products. 

The Valley’s EPS cup molding facility must use higher VOC content beads for quality 

purposes specific to its product line. While 90% of the company’s products are 

produced using batch expanders with ultra-low pentane beads with a VOC content of 

3.2% or less, 10% of products require production on a continuous expander with regular 

pentane beads with a VOC content of 5.4%. These items are customized to print the 

customer’s logo on the cups and to provide increased resistance to leakage. Printing 

on cups made with ultra-low pentane beads results in poor graphic and material quality 

and thus, the limited use of regular pentane beads must be maintained. In South Coast, 

their only cup molding facility was forced to stop production of customized cups once a 

limit of 2.4 pounds of VOC per 100 pounds of throughput was implemented. If the 

Valley facility was forced to comply with the 2.4 limit daily, they would have to do the 

same and eliminate the production of these items because no other alternative exists. 

This would eliminate a major portion of the company’s profits, which could have 

significant economic impacts. 
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A higher daily limit also allows the company to utilize molds for the continuous 

expanders for multiple days to fill orders and to build inventory. Without a higher limit, 

the company would have to purchase additional capital equipment to keep the molds 

throughout the whole month and space out usage to a few hours each day. This type of 

systematic change would require the company to spread production of regular pentane 

bead cups to a small percentage of their production every day. This would decrease 

efficiency, increase natural gas costs, and increase the amount of scrap. The company 

would incur a significant loss of productivity or profits. The inability to fill orders in a 

timely fashion could result in the loss of clientele. 

District staff determined that a daily limit of 3.4 pounds of VOC per 100 pounds of 

throughput is the lowest possible limit that will still allow the facility to produce the 10% 

of products requiring regular pentane beads. By upholding the previous monthly limit 

and a new daily limit, the District is preventing backsliding and enforcing a stricter 

provision. Maintaining the monthly limit ensures that the reliance on the daily maximum 

limit of 3.4 lbs of VOC per 100 pounds of throughput will be kept to a minimum. 

The District’s two tier limit is more stringent than Bay Area’s limit because theoretically, 

a Bay Area EPS cup molding facility could release 2.8 pounds of VOC per 100 pounds 

of throughput every day within a month and still be compliant with the rule. This 

exceeds the 2.4 pounds of VOC monthly limit maintained by the District. Also, Bay 

Area’s rule does not specify a specific averaging time. The rule states that a facility 

cannot exceed the limits at any time. Therefore, the District’s rule maintains more 

stringent enforceability requirements. 

To thoroughly analyze all options available to the affected facilities, the District 

considered the feasibility of cup molders complying via Section 5.2.3 to switch to 

compliance with one of the other four options. 

Section 5.2.4 allows for compliance by the use of a non-VOC blowing agent; however, 

this compliance option is not available to the EPS cup molder. No current EPS 

technology exists using a non-VOC blowing agent and there is no non-VOC EPS 

alternative on the market. 

The next two options (Sections 5.2.5 and 5.2.6) require that at minimum, an emission 

capture system must collect 90% of emissions by weight and shall reduce emissions 

from the capture system at 95% by weight. As previously mentioned, molders have not 

been able to find a feasible, cost-effective method for capturing molding emissions. 

There is no vacuum step in cup molding and thus no vacuum line to collect emissions 

directly off the machine like there is in shape molding. It is impossible to capture the 

cup molding emissions at a 90% level unless the facility encloses the entire 

manufacturing operation. If permanent total enclosure (PTE) is used, the facility would 

need to use over 120,000 cubic feet/minute of captured air to ensure adequate face 

velocity at raw material and personnel entrances, as well as product and personnel exits 
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to keep the work environment adequate by removing the excess heat generated by the 

steam needed for molding. In addition, the use of PTE would have to be combined with 

the use of a RTO system to achieve the 95% control efficiency required by Sections 

5.2.5 and 5.2.6. 

Based on permit data, staff estimates that current practices and technology reduce 

manufacturing emissions from this facility by 66.3% or 57.7 tons per year (tpy). The 

potential manufacturing emissions without controls is 87.1 tpy so the installation of a 

PTE/RTO system at this facility would reduce manufacturing emissions by an additional 

23.3 tpy since RTO systems at other molding facilities achieve a minimum capture and 

control efficiency of 93%. District staff determined the annualized cost of utilizing a 

PTE/RTO system in their current warehouse to be $1,374,627/year, based on EPA 

Office of Air Quality Planning and Standards (OAQPS) guidelines. Therefore, District 

staff estimates the total cost effectiveness of a PTE/RTO system to be $58,997/ton of 

emission reductions. The calculations to support these cost effectiveness figures can 

be found in Appendix D of this final staff report. 

Following the 2007 revision of Rule 4682, the company made significant investments to 

comply. The company is currently paying in excess of $20,000/ton for these emission 

control measures. As a result, the addition of a PTE/RTO system would not be 

financially feasible. Installing a RTO would also be difficult because the company would 

need to relocate its current truck garage so that it could place the RTO in a safe area 

near the boilers and the bead preparation area. The use of the PTE and a RTO is 

neither practical nor economical and would produce NOx emissions from the destruction 

combustion. 

The fourth option, Section 5.2.7, requires the use of beads with an average VOC 

content of 4.2% or less by weight. As previously mentioned, Valley facilities have 

demonstrated a need for using the beads for the continuous expanders with a VOC 

content of 5.4% by weight. Therefore, this option is also unavailable as an alternative 

for the affected company. 

While the aforementioned compliance options and control technologies are effective, 

these do not serve as solutions to bringing the affected source into compliance. As the 

only cup molding facility in the Valley, the company is prone to unique disadvantages, in 

terms of implementing other control systems and having other compliance options. 

Therefore, the District proposes that the addition of a limit of 3.4 pounds of VOC per 100 

pounds of throughput daily to the current monthly limit is RACT for EPS cup molding 

facilities. 

Shape Molding Facilities 

There are currently three shape molding facilities in the Valley. One of the facilities is a 

custom shape molder that specializes in packaging, componentry, and proprietary items 
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production. The other two facilities primarily manufacture EPS table grape boxes that 

allow Valley table grape growers to store and ship grapes without loss of freshness, 

over extended periods of time. This allows the growers to extend their selling season 

domestically and also allows them to compete internationally in a $500,000,000 table 

grape export market that is extremely valuable to the nation and to California. Due to 

the importance of the shape molding industry in the Valley, the District gave thoughtful 

consideration to how these proposed amendments would affect the three facilities. 

Recognizing that there are some differences between the production processes of 

shape and cup molding, the District separately evaluated how shape molding facilities 

would be affected by the inclusion of a daily VOC limit. However, all three EPS shape 

molding facilities utilize one of the other compliance options in Sections 5.2.5-5.2.7 and 

employ an approved VOC control system. None of the facilities are choosing to comply 

with rule requirements with the monthly VOC limit option and as a result, they would not 

be subject to a daily VOC limit with this rule amendment. 

However, one affected shape molding facility has expressed concern with how this rule 

amendment could affect their company if they ever chose to switch compliance options. 

If one of the EPS shape molding facilities switched from their current compliance option 

of Rule 4682 to the requirements of proposed Rule 4682, Section 5.2.3, this would 

modify the facility’s daily potential to emit (PTE). As a result, Best Available Control 

Technology (BACT)/ Lowest Achievable Emissions Rate (LAER) requirements would 

likely be triggered if the adjusted increase in permitted emissions (AIPE) exceeded 2.0 

lb/day for VOC emissions. BACT requires the use of a capture and control system 

consisting of a thermal oxidizer. Since every shape molding facility currently uses a 

thermal oxidizer system, each facility would have to continue the use of this control 

system. 

Since shape molders already comply with a more stringent compliance option and 

cannot choose to comply by utilizing Section 5.2.3 for anti-backsliding purposes, the 

District finds separating the requirements of Section 5.2.3 for shape and cup molding 

facilities to be unnecessary. Therefore, the District proposes that Section 5.2.3 apply to 

all EPS facilities, at this time. 

Section 5.2.7.1 

The District is proposing to make some minor amendments to the proposed rule posted 

on November 15, 2011. The proposed version of the rule changed the language of 

Section 5.2.7.1, by inadvertently deleting annual-averaging provisions. However, 

multiple stakeholders voiced concerns at the public workshop about changing this 

language because allowing an annual-average for the VOC content of the beads is an 

important component of this section and deleting the language would have negative 

implications for Valley facilities. Therefore, in the revised proposed version of the rule, 

the District proposes to leave this section as it was originally. 
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Section 5.5 

In Section 5.5, the District originally proposed to delete the text “No later than March 20, 

2009,” to streamline rule requirements and remove outdated language. However, upon 

further review, the District proposes leaving the phrase in the text because it adds clarity 

to the section. 

C. Section 6.0: Administrative Requirements 

Section 6.1.4 

Section 6.1.4 originally stated that operators shall, “once every day, calculate the daily 

average VOC emissions, for the preceding 24 hour period.” District staff changed this 

section to read, “once every day, calculate the daily VOC emissions,” because the 

original text could be interpreted incorrectly and the District’s original intent was to 

require daily VOC emissions calculations. 

V. GLOBAL CLIMATE CHANGE AND GREENHOUSE GASES 

The California Global Warming Solutions Act of 2006 (AB 32) created a comprehensive, 

multi-year program to reduce greenhouse gas (GHG) emissions in California, with the 

overall goal of restoring emissions to 1990 levels by the year 2020. In the coming 

years, the Air Resources Board (ARB) and the Legislature will be developing policies 

and programs to implement AB 32. The District believes that the evidence and the 

rationale that climate change is occurring is compelling and convincing. In addition to 

the long-term consequences of climate change, the District is concerned with the 

potential ramifications of more moderate but imminent changes in weather patterns. 

The Valley depends heavily on agriculture for its economy and has developed 

agricultural practices based on the last several decades of weather patterns. 

Unanticipated and large fluctuations in these patterns could have a devastating effect 

on the Valley’s economy. 

While there are many win-win strategies that can reduce both GHG and criteria/toxic 

pollutant emissions, when faced with situations that involve tradeoffs between the two, 

District staff believes that the more immediate public health concerns that may arise 

from an increase in criteria or toxic pollutant emissions should take precedence. The 

San Joaquin Valley Air Pollution Control District’s Governing Board adopted the Climate 

Change Action Plan (CCAP) in August 2008. For California Environmental Quality Act 

(CEQA) requirements, one of the goals of the CCAP is to establish District processes 

for assessing the significance of greenhouse gas impacts. The District has developed a 

policy and guidance for addressing greenhouse gases under CEQA. 
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VI. HEALTH BENEFITS 

This rule contributes to the Valley’s progress towards federal health-based air quality 

standards (National Ambient Air Quality Standards, or NAAQS). Progressing the Valley 

towards attainment of the NAAQS helps reduce the Valley’s air pollution-related health 

impacts and health-related costs. The District periodically compiles attainment plans to 

quantify the amount of emissions reductions needed and identifies the individual control 

measures that will achieve these reductions. The control strategy as a whole has 

important public health benefits and health costs savings. 

However, for a number of reasons, it can be difficult or even misleading to attempt to 

subdivide this total plan benefit on a rule-by-rule basis. For example, photochemical 

reactions in the Valley’s atmosphere combine precursor emissions to generate ozone 

and particulate matter in the atmosphere, so it is not always appropriate to attribute the 

health and cost benefits to just one precursor. Also, considering the extensive 

emissions reductions that have already been achieved in the Valley over the past 

several years, some emissions sources may appear relatively small and 

inconsequential from a health perspective. In reality, all attainment plan rule 

commitments are important to the District’s overall strategy for reducing ambient air 

pollutant concentrations and the associated health impacts and costs. 

VII. ANALYSES 

A. Emission Reduction Analysis 

The proposed rule amendments are intended to address the limited approval and 

limited disapproval from EPA concerning RACT. District staff reviewed all subjected 

facility’s permit data and determined units are already in compliance with the proposed 

amendments. Therefore, no emission reductions are expected from this rule-amending 

project. 

B. Cost Effectiveness Analysis 

Pursuant to California Health & Safety Code Section 40920.6(a), the District is required 

to analyze the cost effectiveness of new rules or rule amendments that implement Best 

Available Retrofit Control Technology (BARCT) or planning requirements to incorporate 

all feasible measures. The proposed amendments to this rule would only add federal 

RACT requirements but not BARCT or all feasible measures, and are therefore not 

subject to the cost effectiveness analysis mandate. Given that operators are generally 

complying with the new limits currently and there are no significant emission reductions 

or compliance costs expected from these rule changes, a cost effectiveness analysis 

has not been performed. 
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C. Socioeconomic Analysis 

Pursuant to CH&SC 40728.5(a), “Whenever a district intends to propose the adoption, 

amendment, or repeal of a rule or regulation that will significantly affect air quality or 

emissions limitations, that agency shall, to the extent data are available, perform an 

assessment of the socioeconomic impacts of the adoption, amendment, or repeal of the 

rule or regulation. This section does not apply to the adoption, amendment, or repeal of 

any rule or regulation that results in any less restrictive emissions limit if the action does 

not interfere with the district's adopted plan to attain ambient air quality standards, or 

does not result in any significant increase in emissions.” 

This rule-amending project does not significantly affect air quality and no significant 

emission reductions are expected or claimed. The EPS facility complying via Section 

5.2.3 could be impacted by increased inspection and recordkeeping practices, due to 

the addition of a daily VOC emissions limit. However, District staff has determined that 

the facility already calculates manufacturing emissions daily to meet permit 

requirements so this rule-amending project would primarily result in minor administrative 

changes. Based on discussions with other operators subject to Rule 4682, the changes 

do not create a change to their operations or economic situation since they utilize one of 

the other compliance options. Therefore, staff concludes that, if a detailed 

socioeconomic analysis were conducted, there would be no significant socioeconomic 

impact from this rule. 

D. Environmental Impact Analysis 

Pursuant to §15061 of the Guidelines for Implementation of the California Environmental 

Quality Act (CEQA), District staff investigated the possible environmental impacts of the 

proposed amendments to Rule 4682. Based on the lack of evidence to the contrary, 

District staff has concluded that the proposed amendments to this rule will not have any 

significant adverse effects on the environment. Staff recommends filing a Notice of 

Exemption under the provisions of Public Resource Code 15061(b)(3). 

E. Rule Consistency Analysis 

 

Pursuant to CH&SC §40727.2, District staff prepared a rule consistency analysis that 

compared the elements of amendments with the corresponding elements of other 

District rules and federal regulations. District staff found that none of the proposed 

amendments would conflict with other District rules, or federal rules, regulations, or 

policies covering similar stationary sources. That analysis is presented in Appendix B of 

this Final Staff Report. 
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F. Reasonably Available Control Technology Analysis

CAA §182(b)(2) states that ozone attainment plans shall assure that RACT for VOC is 

applied at certain sources. A RACT analysis requires an examination of a rule against 

Federal rules, regulations, and technology guidelines as well as comparing it against 

rules from other air districts in California. On July 15, 2011 EPA published in the 

Federal Register a RACT analysis of District Rule 4682. As documented in the Federal 

Register, EPA determined that Rule 4682 satisfies RACT with one exception. The 

purpose of this rule-amending project is to address the RACT deficiency as identified by 

EPA and as discussed in this Final Staff Report. As such, this rule satisfies RACT 

requirements. 

 
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VIII. REFERENCES 

Bay Area Air Quality Management District [BAAQMD]. (1999, July 7). Rule 8-52, 

Polystyrene, Polypropylene and Polyethylene Foam Product Manufacturing 

Operations. Retrieved from 

http://www.arb.ca.gov/DRDB/BA/CURHTML/R8-52.HTM 

Environmental Protection Agency [EPA]. (August 1990). Control of VOC Emissions 

From Polystyrene Foam Manufacturing. 

Environmental Protection Agency [EPA]. (January 2002). EPA Air Pollution Control 

Cost Manual. 

Environmental Protection Agency [EPA]. (June 2011). Technical Support Document. 

EPA’s Analysis of San Joaquin Valley Air Pollution Control District’s Rule 4682, 

Polystyrene Foam, Polyethylene & Polypropylene Manufacturing. 

O’Connor, John. (January 1984). Averaging Times for Compliance with VOC Emissions 

Limits—SIP Revision Policy. 

Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air 

Pollution Control District, 76 Fed. Reg. 136, pp 41745-41747. (2011, July 15). (to 

be codified at 40 CFR Part 52) 

San Joaquin Valley Unified Air Pollution Control District [District]. (2011, August 18). 

Rule 4566, Organic Material Composting Operations. Retrieved from 

http://www.valleyair.org/rules/currntrules/Rule4566CleanRule.pdf 

San Joaquin Valley Unified Air Pollution Control District [District]. (September 2007). 

Final Staff Report for Rule 4682, Polystyrene Foam, Polyethylene & 

Polypropylene Manufacturing. 

San Joaquin Valley Unified Air Pollution Control District [District]. (September 2007). 

Rule 4682, Polystyrene Foam, Polyethylene & Polypropylene Manufacturing. 

Retrieved from http://www.valleyair.org/rules/currntrules/r4682.pdf

South Coast Air Quality Management District [SCAQMD]. (2010, November 5). Rule 

1175, Control of Emissions from the Manufacture of Polymeric Cellular (Foam) 

Products. Retrieved from 

http://www.arb.ca.gov/DRDB/SC/CURHTML/R1175.PDF