903R84003
Regional C enter *<,r hmironmentnl Inform.flifii,
I'STPA Region III
1650 Anli SI
Information .QT(, .r^
1650 Arch Street (3PM52)
Philadelphia, PA 19103
VOLATILE ORGANIC COMPOUND EMISSION CONTROLS
FOR TABLET COATING AT PHARMACEUTICAL PLANTS
by
PEDCo Environmental, Inc.
1006 N. Bowen Road
Arlington, Texas 76012
Contract No. 68-02-3512
Task Order No. 43
Project Officer
Eileen Glen
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION III
PHILADELPHIA, PENNSYLVANIA 19106
January 1984
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CONTENTS
Paqe
Tables iii
Summary iv
1. Introduction 1
1.1 Source Description and Types of VOC Emissions 1
2. Emission Control Techniques 5
3. Cost Analysis 7
3.1 Model plants 7
3.2 Assumptions 7
3.3 Capital and annual costs 8
3.4 Cost-effectiveness 10
4. Regulatory Analysis 15
4.1 Draft regulation 15
4.2 Regulation in other areas 18
4.3 Compliance and monitoring techniques 18
4.4 Potential problem areas 20
References 21
Appendix
A List of Pharmaceutical Manufacturing Plants in the
Philadelphia AQCR A-l
B Calculations and Material Balances Around Carbon Adsorbers
Used to Control VOC Emissions During Tablet Coating B-l
C Texas Air Control Board Regulation V, Control of Air Pollu-
tion From Volatile Organic Compounds, Sections 115.231,
115.232, and 115.233 C-l
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TABLES
Number Page
1 Cost of Carbon Adsorber As VOC Control Technique for
Pharmaceutical Tablet Coating Operations 11
2 Costs of A 1000-cfm Adsorber As A VOC Control Technique
At Various Utilization Rates . 12
3 Costs of Catalytic Incinerator-Scrubber Control As VOC
Control Technique for Pharmaceutical Tablet Coating
Operations 14
4 Costs of Refrigerated Vapor Recovery As A VOC Control
Technique for Pharmaceutical Tablet Coating Operations 15
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SUMMARY
Pharmaceutical plants coat tablets with either a water-based or organic-
based material in a batch operation that uses rotating open-ended pans. After
being coated, the tablets are dried by hot air. Most tablets are coated with
sugar, methyl cellulose, or ethyl cellulose. Because sugar coatings are
water-based, they are not a source of volatile organic compound (VOC), emis-
sions. Cellulose coatings can be applied either in water or in an organic
media. An organic solvent is used if faster drying is required or if the
tablet is sensitive to water and/or heat. This process is often referred to
as film coating. A typical organic spray is 80 to 85 percent methylene chlo-
ride, 10 percent denatured alcohol or isopropanol, and 5 to 10 percent solids
(methyl or ethyl cellulose). Chloroform is frequently used in place of methy-
lene chloride.
The most practical VOC emission control method is adsorption,, of the VOC
stream onto activated carbon. The pharmaceutical industry currently uses this
method to control VOC emissions from tablet coating operations. Carbon ad-
sorbers are rugged and simple to operate, and the recovered methylene chloride
or chloroform is suitable for reuse without further treatment. Ethanol and
isopropanol are recovered in dilute aqueous solutions that can be processed in
the plant wastewater treatment facility. Incineration and refrigeration
control methods are technically feasible, but uneconomic. Also, the incinera-
tor exhaust is a potential source of poisonous and corrosive emissions.
This report includes a draft regulation for tablet coating processes that
emit 33 pounds or more VOC per day. This regulation requires the plant to
maintain purchasing and inventory records of solvents, production equipment
schedules, and operating schedules of all control devices, and to have those
records available for examination. It also includes a 2-year compliance
schedule, with the understanding that some flexibility may be required for
specific plants to obtain Food and Drug Administration (FDA) approval of
process modifications.
i v
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SECTION 1
INTRODUCTION
Over the past several years the Office of Air Quality Planning and Stand-
ards (OAQPS) has developed a series of Control Techniques Guidelines (CTGs)
covering volatile organic compounds (VOC) to assist state and local agencies
in developing regulations for VOC control. Although these CTGs have covered
major VOC source categories from an overall nationwide perspective, they do
not cover several VOC source categories that are major contributors to ozone
problems within given areas.
Air pollution control agencies in the Philadelphia Air Quality Control
Region (AQCR) have requested guidance in determining whether VOC controls are
available for non-CTG sources so they can develop appropriate regulations.
One VOC source category under investigation is tablet coating at pharmaceuti-
cal plants. The pharmaceutical industry includes three SIC codes: 2831-
Biological Products; 2833-Medicinal Chemicals and Botanical Products; and
2834-Pharmaceutical Preparations. Appendix A contains a list of the pharma-
ceutical plants in the Philadelphia AQCR.
1.1 SOURCE DESCRIPTION AND TYPES OF VOC EMISSIONS
In contrast with most other chemical manufacturing operations, the pharm-
aceutical industry generally produces small quantities of very expensive
materials. For example, the price per pound of a 59-cent bottle of 100 aspi-
rins is about $8; prescription drugs generally cost one or two orders of
magnitude more. Production is normally in small-scale batch operations and
800 pounds is considered a large run. After one product has been made, the
equipment often is cleaned and used to make a different product.
Tablets are coated in rotating open-ended pans that range from 36 to 60
inches in diameter. The coating is sprayed on the tablets in the pan while
warm air (100°F) flows across the pan at a typical rate of 1000 cubic feet per
minute. Spray coating and drying takes 2 to 3 hours per batch. Figure 1
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presents a flow diagram of this tablet coating operation. A large plant might
have 20 pans; a small plant might have only two. Any number of pans can be in
use at any given time. The pans are usually cleaned after each batch, even if
multiple batches of the same material are made.
Pharmaceutical products also may be coated by the Wurster process. As
shown in Figure 2, in this process the tablets or pellets are suspended in a
fluidized bed while the spray solution is applied. This method is used most
often for coating pellets (smaller particles that are later encapulated),
whereas coating pans are used most often for coating tablets (standard dos-
ages). A good example of pellet coating would be the contents of over-the-
counter 12-hour cold capsules. Tablet coating by the Wurster process requires
a much higher air flow rate than that required for tablet coating in pans.
For a 800-pound batch, the Wurster process typically requires 5000 cfm as
compared to 1000 cfm for pan coating, even though both processes emit equal
amounts of VOCs.
Most tablets are coated with sugar, methyl cellulose, or ethyl cellulose.
Sugar-water solutions are not a source of VOC emissions. Cellulose coatings
may use either a water or an organic solvent. The use of water as a solvent
or solvent component reduces VOC emissions, but more time and heat are re-
quired to evaporate the water than an organic medium. This is a production
consideration. Also, products that are sensitive to water and/or heat may
preclude the use of aqueous coatings. The use of heat or vacuum can expedite
evaporation, but this rapid evaporation can peel or roughen the coating.
A typical organic coating solution consists of 80 to 85 percent methylene
chloride, 10 percent denatured ethanol or isopropanol, and 5 to 10 percent
solids (methyl or ethyl cellulose), (D. Burkit, PEDCo, Inc., personal communi-
cation, September 28, 1983 and J. Jefferson, PEDCo, Inc., personal communica-
tion, December 14, 1983). Chloroform can be used in place of methylene chlo-
ride. One gallon of coating solution will generally process 25 pounds of
tablets.
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TABLET COATING
SOLUTION (SPRAY)
..
AIR, VOC
WARM AIR
FLUIDIZED BED OF .'.
.'• TABLETS OR PELLETS ;.'-
Figure 2. Tablet coati'ng by the Wurster Process.
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SECTION 2
EMISSION CONTROL TECHNIQUES
The most practical method by which to control VOC emissions from the
tablet coating process entails the use of activated carbon adsorption. The
pharmaceutical industry already uses this method, especially to recover methy-
lene chloride solvent (N. R. Shaw, Vic Manufacturing Company, personal commun-
ication, December 6, 1982). Although methylene chloride is not regulated as a
VOC, it meets the definition of a volatile organic compound and is a good
example.
In this control method, the VOC-contaminated air from the dryer is passed
through a bed of activated carbon. When the carbon bed becomes loaded with
organic compounds, it is stripped with low-pressure steam. Because methylene
chloride is insoluble in water, it is easy to separate from the steam conden-
sate for reuse. Any ethanol that is captured is miscible with the steam
condensate and is impractical to salvage. The condensate, which contains 1 to
2 percent alcohol, is usually discarded to the sewer. In a large pharmaceuti-
cal plant, this waste water stream is processed in the plant wastewater treat-
ment system. Discharges from such streams are subject to all applicable
Federal, State, and local wastewater regulations.
Carbon adsorbers are especially suitable for recovering water-insoluble
chlorinated hydrocarbons from dilute air streams. Methylene chloride is
recoverable at a purity that makes it suitable for reuse. Standard designs of
these adsorbers are commercially available, and they are rugged and simple to
operate. They are constructed of stainless steel to withstand the methylene
chloride, and a particulate filter is placed upstream to remove suspended
solids. An adsorber should operate at an efficiency of 90 percent.
Incineration is a technically feasible method of controlling VOC emis-
sions; however, when methylene chloride is burned, it produces chlorine,
hydrogen chloride, and phosgene, which are all corrosive and toxic materials.
An incinerator for organic chlorides also requires special construction mate-
rials and a caustic scrubber to treat the incinerator exhaust. Inasmuch as
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the overall control efficiency of such an incinerator-scrubber system is only
80 percent, incineration does not appear to be a practical VOC control method.
This opinion is shared by California's South Coast Air Quality Management
District (Los Angeles area), (G. Rhett, Senior Air Quality Engineer, South
Coast Air Quality Management District, personal communication, November 29,
1982).
Refrigeration also is a technically feasible method of controlling VOC
emissions from tablet coating operations; however, the high cost of cooling
the dilute air stream to achieve a 90 percent system efficiency makes the
method economically prohibitive. The vapor pressure of methylene chloride is
1 mm Hg at -94°F. With 100°F inlet air at 10 percent relative humidity,
cooling 1000 cfm of air from one large pan would require 58 tons of refrigera-
tion. l
A potential VOC control strategy is either to substitute water-based
coatings for organic-based coatings or to leave the tablets uncoated. The
high costs of organic solvents have already led most manufacturers to use
these two options. For tablets that are susceptible to heat or water, how-
ever, solvent-based coatings seem to be the only feasible coating method.
Consequently, substantial further reductions in emissions as a result of
additional conversion to water-based coatings do not seem likely.
Reformulation of coatings to contain smaller percentages of VOC is not
considered a feasible strategy because all new coatings have to be approved by
the FDA, which would take a long time.
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3. COST ANALYSIS
Although cost estimates have been developed for VOC control of methylene
chloride by carbon adsorption, incineration, and refrigeration, these same VOC
controls and costs apply to chloroform. Only the economics of coating pan
operations are considered in these estimates. Because the Wurster Process has
a much greater air volume, the economics for VOC control would be much less
favorable with this process. All of these control methods are technically
feasible, but incineration and refrigeration are prohibitively expensive.
Therefore, this report focuses on VOC control by carbon adsorption. For the
Wurster process only carbon adsorption was considered.
3.1 MODEL PLANTS
For the Wurster process, costs are based on an adsorber capacity of 5000
cfm drying an 800-pound batch. Costs in pan coating operations have been
developed for plants having adsorber capacities of 1,000, 2,000, 5,000, and
10,000 cfm of VOC-laden air. Each 1,000 cfm of adsorber capacity controls
emissions from a single large tablet coating pan or an equivalent amount of
emissions from a number of smaller pans. An absorber with a capacity of 1,000
cfm will usually serve a small plant; one with a capacity of 2,000 or 5,000
cfm, a medium-sized plant; and one with a capacity of 10,000 cfm, a large
plant. A small plant that uses organic-based coatings exclusively, however,
might be a larger VOC source than a much larger plant that uses numerous
water-based coatings.
3.2 ASSUMPTIONS
A base case adsorber capacity of 1000 cfm is assumed, to correspond with
the air flow required to dry an 800-pound batch of tablets. One gallon of
coating material is used for each 25 pounds of tablets; thus, each batch
requires 32 gallons of coating material. The coating material is 80 volume
7
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percent methylene chloride, 10 volume percent ethanol or isopropanol, and 10
volume percent solids. An air temperature of 100°F, and a required drying
time of 2 hours are assumed (J. Jefferson, PEDCo, Inc., personal communica-
tion, November 24, 1982). Vic Manufacturing Company estimates that 90 percent
of the solvent evaporates in the first 30 minutes and 99, percent in the first
60 minutes (N. R. Shaw, Vic Manufacturing Company, personal communication,
December 6, 1982). After I hour, the carbon adsorber is regenerated with
low-pressure steam.
Proper sizing of the carbon adsorber requires an estimation of the
amounts and concentrations of the solvents in the carrier air stream during
the adsorption cycle. Because the volume of ethanol or isopropanol is small,
the alcohol concentration is always less than 25 percent of the lower explo-
sive limit.2 The combined methylene chloride and alcohol load is about 300
pounds for each adsorber cycle, which requires the use of about 6000 pounds of
activated carbon in the adsorber. Low-pressure steam is used to regenerate
the bed, and about 5 pounds of steam is required to remove 1 pound of organic
material (J. Jefferson, PEDCo, Inc. , personal communication, November 24,
1982). With this information, the ethanol or isopropanol concentrations in
the wastewater stream can then be determined. Step-by-step calculations are
presented in Appendix B.
3.3 CAPITAL AND ANNUAL COSTS
Vic Manufacturing Company has estimated equipment costs for 1,800-,
5,000-, and 10,000-cfm units (N. R. Shaw, Vic Manufacturing Company, personal
communication, December 6, 1982). These estimates suggest that a 0.6 power
rule is appropriate for estimating costs for units of various sizes, and the
0.6 power rule was used to develop the costs for the model plants. The Vic
estimates provide for materials of construction that will withstand prolonged
exposure to methylene chloride. Vic estimated installation costs to be 70
percent of equipment costs (T. Cannon, Vic Manufacturing Company, personal
communication, December 20, 1982).
A comparison of the Vic cost estimates (N. R. Shaw, Vic Manufacturing
Company, personal communication, December 6, 1982) for a 1000-cfm absorber
with estimated costs from the Card report8 showed that the Vic estimate was
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approximately 80 percent of the latter, which is a favorable comparison. The
Vic estimates were used because they are specifically for handling chlorinated
hydrocarbons.
The capital recovery factor for carbon adsorber systems is based on a
20-year life and a 10 percent interest rate. This factor (11.75 percent),
nonvariable operating and maintenance costs (estimated at 4.75 percent), and
property taxes and insurance (estimated at 4.0 percent) add up to 20.5 percent
of the total capital cost. Low-pressure steam is estimated to cost $3.50/1000
pounds (L. Nisbet, PEDCo, Inc., personal communication, December 1, 1982).
Vic estimated that 3 to 4 pounds of steam would be needed to strip 1 pound of
methylene chloride (N. R. Shaw, Vic Manufacturing Company, personal communica-
tion, December 6, 1982). Five pounds of steam per pound of organic compound
was used in this report because alcohol is also present.
The plant is assumed to operate 8 hours per day, 5 days per week, 52
weeks per year (2080 hours per year). Solvent credits are based on 90 percent
recovery (fraction of VOC entering adsorber x adsorber efficiency) and a
quoted solvent price of 26.5 cents per pound of methylene chloride.3
For calculation of the control costs, the adsorber was estimated to
operate 50 percent of the time (1040 hours per year). The tablet coating
operation was estimated to take 2 hours, with 99 percent of the solvent being
evaporated in the first 60 minutes (N. R. Shaw, Vic Manufacturing Company,
personal communication, December 6, 1982). The adsorber operates only'during
the first hour of the tablet coating operation; it is regenerated during the
second hour. There is little advantage to running the very dilute solvent
stream through the adsorber during the second hour; the concentration is so
low that it will actually strip methylene chloride from the adsorber.
Capital costs of catalytic incinerators and scrubbers were obtained from
a published report1 and updated to September 1982 dollars by use of cost
indices published in Chemical Engineering. The economics for catalytic incin-
erators were presented because they represent the lowest-cost incineration
option. The capital recovery factor is based on a 10 percent interest rate
and a 10-year equipment life, which is appropriate for a system that handles
hydrogen chloride, chlorine, and phosgene (combustion reaction products) at
high temperatures.
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Property taxes and insurance were assumed to be 4 percent of total capi-
tal cost, the same as for the carbon adsorber systems. Forty-two percent of
the total capital cost was used for annual operating, maintenance, and materi-
al costs. This value is based on 46 percent of capital costs for a catalytic
incinerator in an EPA report4 and 37 percent for a larger incinerator-scrubber
system used to control emissions at a chemical plant.5 The 90 percent avail-
ability factor was based on 9 years of operating experience at this plant.
Capital and operating costs for VOC control by refrigeration were ob-
tained from a published report1 and updated to September 1982 dollars by using
cost indices published in Chemical Engineering. The capital recovery charge
is based on a 10 percent interest rate and a 12-year equipment life.1 Oper-
ating, maintenance, and material costs are 2.4 percent of capital costs.1
Property taxes and insurance are 4 percent of capital costs. To achieve a 90
percent system efficiency requires that the temperature of the air-methylene
chloride stream be cooled to at least -90°F. This would require 58 tons of
refrigeration for the 1000-cfm stream from one large drying pan.
3.5 COST-EFFECTIVENESS
Capital and annual cost data for the carbon adsorption control technique
are summarized in Tables 1 and 2. Methylene chloride recovery by carbon
adsorption for tablet coating in pans is potentially profitable, and this
profitability is enhanced as the equipment size increases and as the percent
utilization increases. Table 1 shows that for 50 percent equipment utiliza-
tion, a 1000 cfm adsorber has an annual credit of $1900 and a 10,000 cfm
adsorber has an annual credit of $171,000. Table 2 shows that the net credit
for the 1000 cfm adsorber increases as the percent utilization increases. For
obvious reasons, carbon adsorption is extensively used in the pharmaceutical
industry to recover methylene chloride from tablet coating and drying opera-
tions (J. Jefferson, PEDCo, Inc., personal communication, December 14, 1982,
N. R. Shaw, Vic Manufacturing Company, personal communication, December 6,
1982, and L. Nisbet, PEDCo, Inc. , personal communication, December 1, 1982).
The economics for VOC control in the Wurster process are less favorable
due to the higher air consumption. A 5000 cfm adsorber would control emis-
sions from one 800-pound batch in the Wurster process as compared with five
10
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TABLE 1. COSTS OF CARBON ADSORBER AS VOC CONTROL
TECHNIQUE FOR PHARMACEUTICAL TABLET COATING OPERATIONS
(September 1982 dollars)
Equipment cost
Installation costs (70% of
equipment cost)
Total capital cost
Capital recovery factor
Operating and maintenance
costs
Property taxes and insurance
Steam cost
Total annual cost
Solvent credit
Net cost (credit)
Tons of VOC controlled
(ethanol case)
Cost (credit) per ton of
VOC controlled
Carbon adsorption unit capacity, cfm
Coating in pans
1,000
88,000
62,000
150,000
17,600
7,100
6,000
2,500
33,200
35,100
(1,900)
72.0
(26)
2,000
133,000
93,000
226,000
26,600
10,700
9,000
5,000
51,300
70,300
(19,000)
144.1
(132)
5,000
230,000
161,000
391,000
45,900
18,600
15,600
12.600
92,700
175,700
(83,100)
360.2
(231)
10,000
365,000
256,000
621,000
73,000
29,500
24,800
25,200
152,500
351,500
(199,100)
720.5
(276)
Wurster
process
5,000
230,000
161,000
391,000
45,900
18,600
15,600
2,500
82,600
35,100
(47,500
72.0
(660)
Flow rate calculations are based on the molecular weight and density of
ethanol.
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TABLE 2. COSTS OF A 1000-CFM ADSORBER AS A VOC
CONTROL TECHNIQUE AT VARIOUS UTILIZATION RATES
(September 1982 dollars)
Total capital cost
Capital recovery cost
Operating and maintenance
costs
Property taxes and
insurance
Steam cost
Total annual cost
Solvent credit
Net cost (credit)
Tons of VOC controlled
(ethanol case)3
Cost (credit) per ton of
VOC controlled
Annual hours of operation (percent utilization)
416
(20%)
150,000
17,600
7,100
6,000
1,000
31,700
14,100
17,600
28.8
610
832
(40%)
150,000
17,600
7,100
6,000
2,000
32,700
28,100
46,000
57.6
80
1248
(60%)
150,000
17,600
7,100
6,000
3,000
33,700
42,200
(8,500)
86.5
(100)
1664
(80%)
150,000 .
17,600
7,100
6,000
4,000
34,700
56,200
(21,500)
115.3
(190-)
2080
(100%)
150,000
17,600
7,100
6,000
5,000
35,700
70,300
(34,600
144.1
(240)
Flow rate of calculations are based upon the molecular weight and density of
ethanol.
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800-pound batches in coating pans. As seen in Table 1, the costs for VOC
control in the Wurster process are considerably higher than those for emission
control in coating pans.
Capital and annual costs for a catalytic incinerator-scrubber system are
summarized in Table 3. (A scrubber is necessary because combustion of methyl-
ene chloride produces hydrogen chloride.) With the catalytic incinerator-
scrubber, VOC control costs range from $170 to $940 per ton of VOC controlled
compared with a credit of $26 to $276 per ton of VOC controlled with the
carbon adsorber. Table 4 presents the costs for a refrigerated vapor recovery
system. System costs for refrigeration range from $1740 to $2000 per ton of
VOC controlled. Both of these systems are more expensive than the carbon
adsorber. In addition, the overall control efficiency for the incinerator-
scrubber is only 80 percent (it is available only 90 percent of the time at a
90 percent system efficiency). Shutdowns for repairs and maintenance would
require about 10 percent of available operating time.
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TABLE 3. COSTS OF CATALYTIC INCINERATOR-SCRUBBER AS VOC
CONTROL TECHNIQUE FOR PHARMACEUTICAL TABLET COATING OPERATIONS
(September 1982 dollars)
Catalytic incinerator-scrubber capacity, cfm
1,000
Incinerator
Scrubber
Installation costs (100% of
equipment cost)
Total capital cost
Capital recovery cost
Operating, maintenance, and
material costs
Property taxes and insurance
Total annual cost
Tons of VOC controlled (ethanol case)3
Cost per ton of VOC controlled
36,900
12,300
49,200
98,400
16,000
41,300
3,900
61,200
64.8
940
2,000
39,800
13,600
53,400
106,800
17,400
44,900
4,300
66,600
130
510
5,000
49,700
16,000
65,700
131,400
21,400
55,200
5,300
81,900
324
250
10,000
66,700
20,100
86,800
173,600
28,400
72,900
6,900
108,100
649
170
Flow rate calculations are based on the molecular weight and density of
ethanol.
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TABLE 4. COSTS OF REFRIGERATED VAPOR RECOVERY AS A VOC CONTROL
TECHNIQUE FOR PHARMACEUTICAL TABLET COATING OPERATIONS
(September 1982 dollars)
Capital cost
Installation cost (100% of
capital cost)
Total capital cost
Capital recovery cost
Operating, maintenance, and
material costs
Property taxes and insurance
Total annual cost
Credit for recovered solvent
Net cost
Tons of VOC controlled (ethanol
case)
Cost per ton of VOC controlled
Refrigerated vapor recovery system capacity, cfm
1,000
431,000
431,000
862,000
127,000
21,000
34,000
182,000
(38,000)
144,000
72.0
2,000
2,000
814,000
814,000
1,628,000
239,000
39,000
65,000
343,000
(76,000)
267,000
144.0
1,850
5,000
1,964,000
1,964,000
3,928,000
576,000
94,000
157,000
827,000
(191,000)
634,000
360.2
1,760
10,000
3,880,000
3,880,000
7,760,000
1,139,000
186,000
310,000
1,635,000
(382,000)
1,253,000
720.5
1,740
Flow rate calculations are based on the molecular weight and density of
ethanol.
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4. REGULATORY ANALYSIS
This section includes a draft regulation, a discussion of tablet coating
regulations in other areas, applicable compliance and monitoring techniques,
and a discussion of potential problem areas.
4.1 DRAFT REGULATION
A. Definitions--
1. For the purpose of this Regulation, the general definitions apply.
2. For the purpose of this Regulation, the following definitions also
apply.
a. "Control system" means any number of control devices that are
designed and operated to reduce the quantity of VOC emitted to
the atmosphere.
b. "Pharmaceutical manufacturing" means manufacturing of pharma-
ceutical products by any method.
c. "Tablet coating" means applying a coating that has no medicinal
value to a pharmaceutical product.
d. "Carbon adsorber" means a device that adsorbs VOC on activated
carbon in such a manner that VOC emissions to the atmosphere
are reduced to not less than 90 percent of the uncontrolled VOC
emission level.
B. Applicability--
This Regulation applies to all tablet coating facilities at pharma-
ceutical plants that have the potential to emit at least 33 pounds
of VOC per day. All tablet coating takes place at the pharmaceuti-
cal plant where the tablets are manufactured. The purpose of the
coating is to protect the product; therefore, it is applied as early
as possible in the manufacturing process.
C. Provisions for Specific Processes--
1. The owner or operator of a pharmaceutical tablet coating facility
subject to this regulation shall control VOC emissions from all
16
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process equipment that has a VOC potential to emit at least 33
pounds of VOC per day.
2. Carbon adsorbers or equivalent controls shall be used.
3. If equivalent controls are used, the VOC emissions must be reduced
by as much or more than they would be if a carbon adsorber were
used.
4. The owner or operator of a pharmaceutical tablet coating facility
subject to this regulation shall reduce the VOC emissions from all
process equipment:
a. By at least 90 percent if VOC emissions are at least 330 pounds
per day; or
b. To 33 pounds or less per day if VOC emissions are less than 330
pounds/day.
Compliance Schedules--
1. The owner or operator of a pharmaceutical tablet coating facility
subject to this regulation must meet the applicable increments of
progress shown in the following schedule:
a. Submit final plans for all emission control systems and process
equipment within 5 months after this regulation is in effect;
b. Award contracts or purchase orders for all emission control
systems and process equipment within 8 months after this regu-
lation is in effect;
c. Initiate onsite construction or installation of all emission
control and process equipment within 12 months after this
regulation is in effect;
d. Complete onsite construction or installation of the emission
control and process equipment within 18 months after this
regulation is in effect; and
e. Achieve final compliance, determined in accordance with E,
within 24 months after this regulation is in effect.
2. The owner or operator of a pharmaceutical tablet coating facility
subject to this regulation may submit to the Director, and the
Director may approve, a proposed alternative compliance schedule
provided:
a. The proposed alternative compliance schedule is submitted
within 3 months after this regulation is in effect;
b. The owner or operator submits information showing the need for
an alternative schedule;
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c. The alternative compliance schedule contains increments of
progress;
d. Sufficient documentation and certification from appropriate
suppliers, contractors, manufacturers, or fabricators is sub-
mitted by the owner or operator of the pharmaceutical tablet
coating facility to justify the dates proposed for the incre-
ments of progress; and
e. Final compliance is achieved as expeditiously as possible and
before the photochemical oxidant attainment date.
3. The owner or operator of a pharmaceutical tablet coating facility
subject to a compliance schedule of this section shall certify to
, the Director within 5 days after the deadline for each increment of
progress, whether the required increment of progress has been met.
E. Determining Compliance
1. The owner or operator of a VOC source subject to this regulation
shall demonstrate compliance by:
a. Certifying that the appropriate control equipment is in place
and in use;
b. Providing the Director with certified analyses of all tablet
coatings in place and in use. The analyses shall include
determinations of VOC content and solids content and any other
determinations requested by the Director. Analyses may be
provided by the owner-operator of the source, the manufacturer
of the coating solution, or an independent laboratory accept-
able to the Director;
c. Maintaining VOC purchasing, inventory, and consumption records
such that the Director can determine compliance;
d. Maintaining the appropriate control equipment in a manner
consistent with the manufacturer's recommendations; and
e. Maintaining operating and maintenance records on the appropri-
ate control equipment in such a manner that the Director can
determine compliance.
2. The Director may require that the owner or operator of a VOC source
subject to this regulation demonstrate compliance by conducting
emission tests in a manner consistent with U.S. EPA standards. All
tests shall be made by or under the direction of a person qualified
by training and/or experience in the field of air pollution testing.
The Director shall receive at least 30 days advance notice of such
testing so that the Director and/or his authorized representative(s)
may witness the test.
18
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The EPA guidelines for synthesized pharmaceutical industry VOC sources
set a lower limit of 33 pounds per day for air dryers and production equipment
exhaust systems. The guidelines also allow an extension of the compliance
schedule, if necessary, to obtain Food and Drug Administration (FDA) permits.6
A similar guideline should apply to tablet coating operations in pharmaceuti-
cal plants because these are air drying operations.
4.2 REGULATION IN OTHER AREAS
No applicable BACT/LAER determinations, New Source Performance Standards,
or other regulations Were found that apply to tablet coating in the pharma-
ceutical industry. California's South Coast Air Quality Management District
(SCAQMD) and the Texas Air Control Board have regulations similar to those
proposed in EPA's CTG document. The applicability limits for California,
however, is 1 ton per year. A SCAQMD representative said that the regulation
covers tablet coating. A copy of the Texas regulations is included as Appen-
dix C. The SCAQMD and Texas regulations both follow EPA guidelines and are
the same with the exception of a lower cutoff limit in California. The Texas
regulations apply to tablet coating processes using air dryer and exhaust
systems.
4.3 COMPLIANCE AND MONITORING TECHNIQUES
Emissions can be estimated accurately from solvent inventories and pur-
chasing records, and these records can be verified by spot inspections. The
plant may also demonstate compliance by submitting monthly material balances
for tablet coating operations.
Because solvent recovery by carbon adsorption is potentially profitable,
many pharmaceutical companies already have carbon adsorbers in place. The
principal and most frequent monitoring activities are:
1. Determining that sufficient adsorber capacity exists to con-
trol VOC emissions at all times; and
2. Determining that all significant VOC emissions are routed
through control devices.
For maximum usage, an adsorber may be connected to several coating pans
and/or dryers. Because of the batch operations, it is possible for more
19
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equipment to be in operation than the adsorber can service at certain times,
and that some VOC emissions might bypass the adsorber during these periods.
The responsible agency should require assurance that this will not happen. It
may be necessary to write a conditional operating permit that allows only
those operating combinations that do not generate emissions that exceed
1imits.
4.4 POTENTIAL PROBLEM AREAS
If purchasing and inventory records indicate that VOC emissions are
excessive, the agency may find it necessary to examine production and oper-
ating schedules to determine whether the control equipment is adequate to
comply with regulations. This will necessitate obtaining the following infor-
mation:
1. Operating schedules for all equipment connected to the adsorber;
2. VOC quantities potentially routed to the adsorber; and
3. Operating capacity and schedule of the adsorber.
For example, if the adsorber is regenerated during the first hour that a
tablet coating pan is operating, VOC would bypass the adsorber. If the ad-
sorbers are used at or near capacity, small fluctuations in the schedule or
adsorber malfunctions could result in VOC emissions. Some reserve adsorber
capacity may be appropriate. The control agency should frequently examine a
company's solvent purchasing and inventory records and production schedules
and have a good understanding of the capabilities of the company's control
equipment.
20
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REFERENCES
1. Neveril, R. B. Capital and Operating Costs of Selected Air Pollution
Control Systems. Card, Inc. EPA 450/5-80-002, December 1978. pp. 5-65
to 5-73.
2. McDermott, H. J. Handbook of Ventilation for Contaminant Control. Ann
Arbor Science Publishers, Inc., Ann Arbor, Michigan. 1976. p. 49.
3. Price of NF Grade Methylene Chloride. Chemical Marketing Reporter,
November 22, 1982.
4. U.S. Environmental Protection Agency. Control Technique Guidelines for
the Control of Volatile Organic Emissions From Wood Furniture Coating.
(Draft) Office of Air and Waste Management, Office of Air Quality Plan-
ning and Standards, Research Triangle Park, North Carolina. April 1979.
5. Hall, F. D. Incineration System Summary Report. Inspection and Evalua-
tion of the Incinerator Scrubber System Used for Incinerating Organic
Chlorides at PPG Industries, Lake Charles, Louisiana Plant. April 28,
1982.
6. Capone, S. V., and M. Petroccia. Guidance to State and Local Agencies in
Preparing Regulations to Control Volatile Organic Compounds from Ten
Stationary Source Categories. EPA-450/2-79-004, September 1979.
21
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APPENDIX A
LIST OF PHARMACEUTICAL MANUFACTURING PLANTS
IN THE PHILADELPHIA AQCR
DELAWARE
ICI Americols, Inc.
Stuart Pharmaceuticals Division
Newark
Newark
NEW JERSEY
Elkins-Sinn, Inc.
Ganes Chemicals, Inc.
Heather Drug Co., Inc.
Cherry Hill
Pennsvi1le
Cherry Hill
PENNSYLVANIA
American Home Products Corp.
American Home Products Corp.
Carroll Products, Inc.
Certified Laboratories, Inc.
Gordon Laboratories
High Chemical Co.
Lannett Company, Inc.
McNeil Laboratories, Inc.
Merck, Sharpe and Dohme, Inc.
Moyco Industries, Inc.
William H. Rover, Inc.
Schuylkill Chemical Co.
Smith, Kline and French
Smith, Kline and French
Laboratories
Laboratories
Vicks Health Care Division
Wyeth Laboratories, Inc.
Wyeth Laboratories, Inc.-Green Valley
Radner
Paoli
Philadelphia
Warrington
Upper Darby
Philadelphia
Philadelphia
Fort Washington
West Point
Philadelphia
Fort Washington
Philadelphia
Philadelphia
Swedeland
Hatboro
West Chester
Maivern
A-l
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APPENDIX B
CALCULATIONS AND MATERIAL BALANCES AROUND CARBON ADSORBERS
USED TO CONTROL VOC EMISSIONS DURING TABLET COATING
DESIGN CONDITIONS
1. The batch is 800 pounds; 1 gallon of coating material is used per 25
pounds of tablets (32 gallons per batch).1
2. The coating material composition (in volume percent) is methylene
chloride, 80; ethanol or isopropanol, 10; and solids, 10. *
3. The air flow rate and temperature are 1000 cfm at 100°F (38°C).1
4. The drying period is 2 hours. Ninety percent of the solvent is eva-
porated in 30 minutes and 99 percent in 60 minutes.3 The carbon
adsorber is regenerated after 1 hour.
5. The lower explosion limit for ethanol is 4.3 percent; for isopropan-
ol, it is 2.0 percent.8
6. Liquid densities are ethanol, 0.9182 g/ml; isopropanol, 0.7812 g/ml;
and methylene chloride, 1.3266 g/ml.
VOC VOLUMES
1. Ethanol, 32 gal x 10% =3.2 gallons
3.2 gal x 3.785 liters/gal x 1000 ml/liter x 0.9182 g/ml -f 46.06
g/mole = 241.4 moles
Vapor volume
241.4 mole x 22.4 liters/mole x (311K/273K) x 0.03531 ftVliter
= 218 ft3
2. Isopropanol, 32 gal x 10% =3.2 gal
3.2 gal x 3.785 liters/gal x 1000 ml/liter x 0.7812 g/ml 4- 60.09
g/mole = 157.5 moles
B-l
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Vapor volume
157.5 moles x 22.4 liters/mole x (311K/273K) x 0.03531 ftVliter
= 142 ft3
3. Methylene chloride, 32 gal x 80% = 25.6 gal
25.6 gal x 3.785 liters/gal x 1000 ml/liters x'l.3266 g/ml + 84.93
g/mole = 1514 moles
Vapor volume
1514 moles x 22.4 liters/mole x (311K/273K) x 0.03531 ftVliter
= 1364 ft3
FLOW RATES THROUGH THE CARBON BED
Air flow rate = 1000 cubic feet per minute.
1. First 30 minutes - 90 percent of VOC evaporated.
a. Ethanol + methylene chloride
Total flow = (1000 ft3/min x 30 min) + 90% x (218 ft3 + 1364 ft3)
= 31,423 fts/30 min
= 1047 ftVmin
Ethanol concentration:
90% x 218 ft3/31,423 ft3 = 0.62%
Lower explosive limit (LEL) = 4.3%
% of LEL = (0.62/4.3) x 100% = 14%
Methylene chloride concentration
90% x 1364 ft3/31,423 ft3 = 3.91%
b. Isopropanol + methylene chloride:
Total flow = (1000 ft3/min x 30 min) + 90% x (142 ft3 + 1364 ft3)
= 31,355 ft3/30 min
= 1,045 ftVmin
B-2
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Isopropanol concentration:
90% x 142 ft3/31,355 ft3 =0.4%
LEL = 2%
% of LEL + (0.41/2) x 100% = 20%
Methylene chloride concentration:
90% x 1364 ft3/31,355 ft3 = 3.9%
2. Second 30 minutes - 9 percent of VOC evaporates
a. Ethanol + methylene chloride:
Total flow = (1000 ftVmin x 30 min) + 9% x (218 ft3 + 1364 ft3)
= 30,142 ft3/30 min
= 1005 ftVmin
Ethanol concentration:
9% x 218 ft3/30,142 ft3 = 0.07%
Methylene chloride concentration percent:
9% x 1364 ft3/30,142 ft3 =0.41%
b. Isopropanol + methylene chloride:
Total flow = (1000 ft3/min x 30 min) + 9% x (142 ft3 + 1364 ft3)
= 30,136 ft3/30 min
= 1005 ftVmin
Isopropanol concentration:
9% x 142 ft3/30,136 ft3 = 0.04%
Methylene chloride concentration:
9% x 1364 ft3/30,136 ft3 = 0.41%
UNCONTROLLED VOC EMISSIONS PER CYCLE
1. Ethanol = 3.2 gal x (0.9182 x 8.342) Ib/gal = 24.5 Ib
B-3
-------
2. Isopropanol = 3.2 gal x (0.7812 x 8.345) Ib/gal = 20.9 Ib
3. Methylene chloride = 25.6 gal x (1.3266 x 8.345) Ib/gal = 283.4 Ib
Total VOC (Ethanol + methylene chloride) = 283.4 Ib + 24.5 Ib = 308 Ib
Assuming a capacity of 1 pound of organic vapor per 10 pounds of carbon
and using a safety factor of 2.
Carbon requirement is 307.9 Ib organic vapor x 10 Ib carbon/lb organic
vapor x 2 = 6200 Ib carbon per bed
ALCOHOL CONCENTRATIONS IN WASTEWATER STREAMS
About 5 pounds of steam is required to remove 1 pound of organic vapor
Water = 308 Ib organic vapor x 5 Ib steam/lb organic vapor
= 1540 Ib steam
Ethanol concentration = 100% x 24.5 lb/1540 Ib = 1.6% in water
Isopropanol concentration = 100% x 20.9 lb/1540 Ib = 1.4%
B-4
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APPENDIX C
TEXAS AIR CONTROL BOARD
REGULATION V
CONTROL OF AIR POLLUTION FROM
VOLATILE ORGANIC COMPOUNDS
C-l
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TEXAS AIR COHTHOL BOARD
REGULATION V
(31 TAG CHAPTER 115)
COMTIROL OF AIR POLLUTION
FROM VOLATILE ORGANIC COMPOUNDS
RE¥ISED HARCH 20, 1981
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Texas Air Control Board
Control of Air Pollution
from Volatile Organic
Compounds
Regulation V
Page 60 of 79
(1) Facilities where an adsorber cannot be accommo-
dated because of inadequate space.
(2) Facilities with insufficient steam capacity
to desorb adsorbers.
(c) Any perchloroethylene dry cleaning facility located
in Bexar, Brazoria, Dallas, El Paso, Galveston, Gregg, Jefferson,
Mueces, Orange, Tarrant , or Victoria County which when uncon-
trolled would emit a combined weight of volatile organic
compounds of less than 550 pounds (250 kg) in any consecutive
24-hour period is exempt from the provisions of §115.221
of this title (relating to Control Requirements).
§115.223. Coapliance Schedule and Counties.
The provisions of §115.221 of this title (relating to
Control Requirements) shall apply only within Bexar, Brazoria,
Dallas, El Paso, Galveston, Gregg, Harris, Jefferson, Nueces,
Orange, Tarrant, and Victoria Counties. All affected persons
shall submit to the Texas Air Control Board a control plan
for compliance with these provisions no later than December 31,
1980, and shall be in compliance as soon as practicable but
no later than December 31, 1982.
PHARMACEUTICAL HAiTOF&CTURIHG FACILITIES 12!
BEXAR, BRAZORIA, DALLAS, EL PASO, GALVESTOM,
GREGG, HARRIS, JEFFERSON, MUECES, ORAKGE,
TARRAMT, AMD VICTORIA COUNTIES
§115.231. Control Requirements,
July 11, 1980
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Texas Air Control Board Page 61 of 79
Control of Air Pollution
from Volatile Organic
Compounds
Regulation V
The owner or operator of a synthesized pharmaceutical
manufacturing facility shall provide the following specified
controls for the following specific sources in his facility:
(1) Reactors, distillation units, crystalli^erst cent-
rifuges, and vacuum dryers. The emission of volatile organic
compounds from these sources shall be controlled by means
of surface condensers or other equivalent controls.
(A) If surface condensers are used, the condenser
outlet gas temperature must not exceed the following:
When VOC Vapor Pressure Outlet gas
At 68 F (20 C) Exceeds Maximum Temperature
5.8 psia (40 kPa) -13°F (-25°C)
2.9 psia (20 kPa) 5°F (_15°C)
1.5 psia (10 kPa) 32°F ( 0°C)
1.0 psia ( 7 kPa) 50°F ( 10°C)
0.5 psia (3.5 kPa) 77°F ( 25°C)
(B) If equivalent controls are used, the volatile
organic compound emissions must be reduced by at least as
much as they would have been reduced by the use of a surface
condenser which meei-s the requirements in paragraph (1)(A)
of this section.
(2) Air dryers and exhaust systems. Volatile organic
compound emissions from all air dryers and production equip-
ment exhaust systems shall be reduced by at least 90 percent
of the uncontrolled emissions or to 33 Ib/day (15 kg/day)
whichever is the least stringent limit.
July 11, 1980
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Texas Air Control Board Page 62 of 79
Control of Air Pollution
from_ Volatile Organic
Compounds
Regulation V
(3) Loading Facilities. Emissions from truck or railcar
deliveries to storage tanks with capacities greater than
2,000 gallons (7,500 liters) that store volatile organic
compounds with vapor pressures greater than 4.1 psia (28
kPa) at 68°F (20°C) shall be reduced by at least 90% of the
uncontrolled emissions by means of a vapor balance system
or equivalent control.
(A) Tanks.
(A) All in-process tanks that contain volatile
organic compounds at any time shall be kept covered, except
when production, sampling, maintenance, or inspection pro-
cedures require operator access.
(B) All storage tanks that store volatile organic
compounds which have vapor pressures greater than 1.5 psia
(10.3 kPa) at 68°F (20°C) shall have pressure vacuum conserva-
tion vents installed which are set at ±0.8 inches of water
(±0.2 kPa), unless a more effective control system is used.
(5) Centrifuges and Filters. Centrifuges, rotary vacuum
filters and other filters having an exposed liquid surface
which process liquids containing volatile organic compounds
with vapor pressure equal to or greater than 0.5 psia (3.A kPa)
at 68°F (20°C) shall be enclosed.
iV. (6) Liquid Leaks. All leaks from which any liquid
kf containing volatile organic compound can be observed running
tf(v
i£te' or dripping shall be repaired the first time the equipment
"~" is off-line long enough to complete the repair.
July 11, 1980
-------
Texas Air Control Board Page 63 of 79
Control of Air Pollution
from Volatile Organic
Compounds
Regulation V
§115.232. Exe-ptlcns.
(a) Any facility in Bexar, Brazoria, Dallas, El Paso,
Galveston, Gregg, Jefferson, Nueces, Orange, Tarrant, or
Victoria County which, when uncontrolled, will emit a com-
bined weight of volatile organic compounds less than 550
pounds (250 kg) in any consecutive 24-hour period is exempt
from the provisions of §115.231 of this title (relating to
Control Requirements).
(b) Any facility located in Harris County which, when
uncontrolled, will emit a combined weight of volatile organic
compounds less than 15 pounds (6.8 kg) in any consecutive
24-hour period is exempted from the provisions of §115.231
of this title (relating to Control Requirements).
§115-233. Compliance Schedule and Counties.
The provisions of §115.231 of this title (relating to
Control Requirements) shall apply within Bexar, Brazoria,
Dallas, El Paso, Galveston, Gregg, Harris, Jefferson, Nueces,
Orange, Tarrant, and Victoria Counties. All affected persons
shall submit a final control plan to the Texas Air Control
Board no later than December 31, 1980, and shall be in compli.
ance with these rules as soon as practicable but no later
than December 31, 1982.
July 11, 1980
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