64532 Federal Register / Vol. 62, No. 235 / Monday, December 8, 1997 / Proposed Rules

indexed securities are different from

interest components stripped from

fixed-principal securities and,

accordingly, are not interchangeable for

reconstitution purposes.

(e) Applicable regulations. Unless

otherwise provided in this part, notes

and bonds stripped into their STRIPS

components are governed by subparts A,

B, and D of part 357 of this chapter.

4. Appendix B to part 356 is amended

by revising the list of section headings

at the beginning of the appendix to read

as follows:

Appendix B to Part 356—Formulas and

Tables

I. Computation of Interest on Treasury Bonds

and Notes.

II. Formulas for Conversion of FixedPrincipal Security Yields to Equivalent

Prices.

III. Formulas for Conversion of InflationIndexed Security Yields to Equivalent

Prices.

IV. Computation of Adjusted Values and

Payment Amounts for Stripped InflationIndexed Interest Components.

V. Computation of Purchase Price, Discount

Rate, and Investment Rate (CouponEquivalent Yield) for Treasury Bills.

* * * * *

5. Appendix B to Part 356 is amended

by redesignating Section IV as Section V

and adding a new Section IV to read as

follows:

* * * * *

IV. Computation of Adjusted Values and

Payment Amounts for Stripped InflationIndexed Interest Components

Note: Valuing an interest component

stripped from an inflation-indexed security at

its adjusted value enables this interest

component to be interchangeable (fungible)

with other interest components that have the

same maturity date, regardless of the

underlying inflation-indexed security from

which the interest components were

stripped. The adjusted value provides for

fungibility of these various interest

components when buying, selling, or

transferring them, or when reconstituting an

inflation-indexed security.

Definitions

C=the regular annual interest rate, payable

semiannually, e.g., 3.625% (the decimal

equivalent of a 3–5⁄8% interest rate)

Par=par amount of the security to be stripped

Ref CPIIssue Date=reference CPI for the original

issue date (or dated date, when the dated

date is different from the original issue

date) of the underlying (unstripped)

security

Ref CPIDate=reference CPI for the maturity

date of the interest component

AV=adjusted value of the interest component

PA=payment amount at maturity by Treasury

Formulas

AV=Par (C/2)(100/Ref CPIIssue Date) (rounded

to 2 decimals with no intermediate

rounding)

PA=AV (Ref CPIDate/100) (rounded to 2

decimals with no intermediate rounding)

Example. A 10-year inflation-indexed note

paying 31⁄2% interest is issued on January 15,

1999, with the second interest payment on

January 15, 2000. The Ref CPI on January 15,

1999 (Ref CPIIssue Date) is 174.62783, and the

Ref CPI on January 15, 2000 (Ref CPIDate) is

179.86159. Calculate the adjusted value and

the payment amount at maturity of the

interest component.

Definitions

C=3.50%

Par=$1,000,000

Ref CPIIssue Date=174.62783

Ref CPIDate=179.86159

Resolution

For a par amount of $1 million, the

adjusted value of each stripped interest

component is $1,000,000 (.035/2)(100/

174.62783), or $10,021.31 (no intermediate

rounding).

For an interest component maturing on

January 15, 2000, the payment amount is

$10,021.31×(179.86159/100), or $18,024.49

(no intermediate rounding).

* * * * *

6. Exhibit C to Part 356 is amended

by revising the heading to read as

follows:

Exhibit C to Part 356—Minimum Par

Amounts for Fixed-Principal STRIPS

* * * * *

[FR Doc. 97–31953 Filed 12–5–97; 8:45 am]

BILLING CODE 4810–39–P

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Part 51

[FRL–5930–6]

RIN 2060–AG88

Preparation, Adoption, and Submittal

of State Implementation Plans;

Appendix M, Test Method 207

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Proposed rule and notice of

public hearing.

SUMMARY: The purpose of this proposed

rule is to add a validated stationary

source test method for the measurement

of isocyanate emissions from stationary

sources to the Code of Federal

Regulations. This method, validated

according to EPA Method 301 criteria,

would be used to reliably collect and

analyze gaseous isocyanate emissions

from stationary sources such as flexible

foam manufacturers, automobile paint

spray booths, and the pressed board

industry. Specifically, methylene

diphenyl diisocyanate (MDI), methyl

isocyanate (MI), hexamethylene 1,6-

diisocyanate (HDI), and 2,4-toluene

diisocyanate (TDI) are the gaseous

pollutants in source emissions to be

measured. The test method is entitled,

‘‘A Method for Measuring Isocyanates in

Stationary Source Emissions,’’ and will

be added to 40 CFR Part 51, Appendix

M, as Test Method 207. This method

will provide a tool for state and local

governments, representatives of private

industry, and the U.S. Government to

reliably monitor stationary sources for

isocyanate emissions with a validated

stationary source method. Additionally,

this method will allow the U.S.

Environmental Protection Agency to

comply with the requirements of the

Clean Air Act Amendments of 1990 for

monitoring these hazardous air

pollutants. Prior to the development of

this method, no other ‘‘validated’’

method has been available to monitor

these highly reactive hazardous

emissions. Isocyanates are used

extensively in the production of

polyurethane materials such as flexible

foam, enamel wire coatings, paint

formulations, and in binders for the

pressed board industry. A public

hearing will be held, if requested, to

provide interested persons an

opportunity for oral presentation of

data, views, or arguments concerning

the proposed method.

DATES: Comments. Comments must be

received on or before February 23, 1998.

Public Hearing. If anyone contacts

EPA requesting to speak at a public

hearing by December 29, 1997, a public

hearing will be held January 22, 1998

beginning at 10:00 a.m. Persons

interested in attending the hearing

should call the contact mentioned under

ADDRESSES to verify that a meeting will

be held.

Request to Speak at Hearing. Persons

wishing to present oral testimony must

contact EPA by December 29, 1997.

ADDRESSES: Comments. Comments

should be submitted (in duplicate if

possible) to: Central Docket Section

(Mail Code: 6102), Attention: Docket

Number A–96–06, U.S. Environmental

Protection Agency, Room M–1500, First

Floor, Waterside Mall, 401 M Street,

S.W., Washington, D.C. 20460.

Public Hearing. If anyone contacts

EPA requesting a public hearing, it will

be held at EPA’s Emission Measurement

Center, Research Triangle Park, North

Carolina. Persons interested in attending

the hearing or wishing to present oral

testimony should notify Frank Wilshire,

Methods Branch (MD–44), Air
Federal Register / Vol. 62, No. 235 / Monday, December 8, 1997 / Proposed Rules 64533

Measurements Research Division,

National Exposure Research Laboratory,

U.S. Environmental Protection Agency,

Research Triangle Park, North Carolina

27711, telephone number (919) 541–

2785.

Docket. Docket No. A–96–06,

containing materials relevant to this

rulemaking, is available for public

inspection and copying between 8:00

a.m. and 5:30 p.m., Monday through

Friday, at EPA’s Air Docket Section,

Room M–1500, First Floor, Waterside

Mall, 401 M Street, S.W., Washington,

D.C. 20460. A reasonable fee may be

charged for copying.

FOR FURTHER INFORMATION CONTACT:

Frank Wilshire, at the address listed

under Public Hearing, or Gary

McAlister, Source Characterization

Group B (MD–19), Emissions

Monitoring and Analysis Division, U.S.

Environmental Protection Agency,

Research Triangle Park, North Carolina

27711, telephone number (919) 541–

1062.

SUPPLEMENTARY INFORMATION:

I. The Rulemaking

A. Summary of Proposed Method

The U.S. Environmental Protection

Agency, under the authority of Title III

of the Clean Air Act Amendments of

1990, requires the development of a

validated (per EPA Method 301 criteria)

stationary source sampling and analysis

method for the following isocyanates:

methyl isocyanate, methylene diphenyl

diisocyanate, hexamethylene 1,6-

diisocyanate, and 2,4-toluene

diisocyanate. The isocyanate sampling

method developed is a modification of

the EPA Method 5 sampling train (no

filter and the addition of impingers),

employing impingers and a derivatizing

reagent [1-(2-pyridyl)piperazine in

toluene] to immediately stabilize the

isocyanates upon collection. Collected

samples are analyzed under laboratory

conditions sufficient to separate and

quantify the isocyanates, using high

performance liquid chromatography

with ultra violet detection.

B. Comments and Responses on Draft

The proposed method is available by

request. Requests should be made to:

Frank Wilshire (MD–44), Methods

Branch, U.S. Environmental Protection

Agency, Research Triangle Park, NC

27711. To date, over thirty-five copies of

the isocyanate method have been

requested by representatives of the

private sector, state and local

governments, industry trade

associations, and the Canadian

Government.

On June 7, 1995 a presentation was

made before members of the Analytical

and Environmental Subcommittee of the

International Isocyanate Institute to

review the method and address the

timetable and procedure for including

the isocyanate method in the Code of

Federal Regulations (CFR). Members of

the Subcommittee were enthusiastic

about the method and inquired when it

might be included in the Code of

Federal Regulations. To date, no

technical comments have been received

from other sources. Oral comments have

been received by many of those

requesting copies of the method,

suggesting publication of the method in

the CFR. This action would establish a

reference method for the collection and

analysis of isocyanates from stationary

sources and aid in standardizing

monitoring of isocyanate emissions from

these sources.

II. Administrative Requirements

A. Public Hearing

A public hearing will be held, if

requested, to discuss the proposed

rulemaking in accordance with Section

307(d)(5) of the Clean Air Act. Persons

wishing to make oral presentations

should contact EPA at the address given

in the ADDRESSES section of this

preamble. Oral presentation will be

limited to 15 minutes each. Any

member of the public may file a written

statement with the EPA before, during,

or within 30 days after the hearing.

Written statements should be addressed

to the Central Air Docket Section

address given in the ADDRESSES section

of this preamble.

A verbatim transcript of the hearing

and written statements will be available

for public inspection and copying

during normal working hours at EPA’s

Central Air Docket Section in

Washington, D.C. (see ADDRESSES

section of this preamble).

B. Docket

The docket is an organized and

complete file of all the information

submitted to or otherwise considered by

the EPA in the development of this

proposed rulemaking. The principal

purposes of the docket are to: (1) Allow

interested parties to identify and locate

documents so that they can effectively

participate in the rulemaking process,

and (2) serve as the record in case of

judicial review except for interagency

review materials [Section 307(d)(7)(A)].

C. Office of Management and Budget

Review

Under Executive Order 12866 (58 FR

51735, October 4, 1993), the EPA is

required to judge whether a regulation

is ‘‘significant’’ and therefore subject to

Office of Management and Budget

(OMB) review and the requirements of

this Executive Order to prepare a

regulatory impact analysis. The Order

defines ‘‘significant regulatory action’’

as one that is likely to result in a rule

that may: (1) Have an annual effect on

the economy of $100 million or more or

adversely affect in a material way the

economy, a sector of the economy,

productivity, competition, jobs, the

environment, public health or safety, or

State, local, or tribal governments or

communities; (2) create a serious

inconsistency or otherwise interfere

with an action taken or planned by

another agency; (3) materially alter the

budgetary impact of entitlements,

grants, user fees, or loan programs, or

the rights and obligation of recipients

thereof; or (4) raise novel legal or policy

issues arising out of legal mandates, the

President’s priorities, or the principles

set forth in the Executive Order.

Pursuant to the terms of the Executive

Order, this action has been determined

to be ‘‘not significant.’’

D. Regulatory Flexibility Act

Compliance

The Regulatory Flexibility Act (RFA)

generally requires an agency to conduct

a regulatory flexibility analysis of any

rule subject to notice and comment

rulemaking requirements unless that

Agency certifies that the rule will not

have a significant economic impact on

a substantial number of small entities.

Small entities include small businesses,

small not-for-profit enterprises, and

small governmental jurisdictions. This

proposed rule would not have a

significant impact on a substantial

number of small entities because the

overall impact of these amendments is

a net decrease in requirements on all

entities including small entities.

Therefore, I certify that this action will

not have a significant economic impact

on a substantial number of small

entities.

E. Paperwork Reduction Act

The rule does not change any

information collection requirements

subject of Office of Management and

Budget review under the Paperwork

Reduction Act of 1980, 44 U.S.C. 3501

et seq.

F. Unfunded Mandates

Under Section 202 of the Unfunded

Mandates Reform Act of 1995

(‘‘Unfunded Mandates Act’’), signed

into law on March 22, 1995, EPA must

prepare a budgetary impact statement to

accompany any proposed or final rule
64534 Federal Register / Vol. 62, No. 235 / Monday, December 8, 1997 / Proposed Rules

that includes a Federal mandate that

may result in estimated costs to State,

local, or tribal governments in the

aggregate; or to the private sector, of

$100 million or more. Under Section

205, EPA must select the most costeffective and least burdensome

alternative that achieves the objectives

of the rule and is consistent with

statutory requirements. Section 203

requires EPA to establish a plan for

significantly or uniquely impacted by

the rule.

EPA has determined that the action

proposed today does not include a

Federal mandate that may result in

estimated costs of $100 million or more

to either State, local, or tribal

governments in the aggregate, or to the

private sector, nor does this action

significantly or uniquely impact small

governments, because this action

contains no requirements that apply to

such governments or impose obligations

upon them. Therefore, the requirements

of the Unfunded Mandates Act do not

apply to this action.

List of Subjects in 40 CFR Part 51

Environmental protection, Air

pollution control, Hazardous air

pollutants, Polyurethane production,

Flexible foam manufacturing, Enamel

wire coatings, Manufactured wood

products, Isocyanates.

Dated: November 25, 1997.

Carol M. Browner,

Administrator.

It is proposed that 40 CFR part 51 be

amended to read as follows:

1. The authority citation for part 51

continues to read as follows:

Authority: 42 U.S.C. 7401, 7411, 7412,

7413, 7414, 7470–7479, 7501–7508, 7601,

and 7602.

2. Appendix M to part 51 is amended

by adding Method 207 in numerical

order to read as follows:

Appendix M to Part 51—Recommended

Test Methods for State Implementation

Plans

* * * * *

Method 207—A Method for

Measuring Isocyanates in Stationary

Source Emissions.

Note: This method is not inclusive with

respect to specifications (e.g., equipment and

supplies) and sampling procedures essential

to its performance. Some material is

incorporated by reference from other EPA

methods. Therefore, to obtain reliable results,

persons using this method should have a

thorough knowledge of at least Method 1,

Method 2, Method 3, and Method 5 found in

Part 60 of this title.

1.0 Scope and Application.

1.1 This method is applicable to the

collection and analysis of isocyanate

compounds from the emissions associated

with manufacturing processes. The following

is a list of the isocyanates and the

manufacturing process at which the method

has been evaluated:

Compound name CAS No.

Detection

limits a (ng/

m3)

Manufacturing process

2,4-Toluene Diisocyanate (TDI) ............................................................................. 584–8

4–9

106 Flexible Foam Production.

1,6-Hexamethylene Diisocyanate (HDI) ................................................................. 822–0

6–0

396 Paint Spray Booth.

Methylene Diphenyl Diisocyanate (MDI) ................................................................ 101–6

8–8

112 Pressed Board Production.

Methyl Isocyanate (MI) ........................................................................................... 624–8

3–9

228 Not used in production.

aEstimated detection limits are based on a sample volume of 1 m3 and a 10-ml sample extraction volume.

2.0 Summary of Method.

2.1 Gaseous and/or aerosol isocyanates

are withdrawn from an emission source at an

isokinetic sampling rate and are collected in

a multicomponent sampling train. The

primary components of the train include a

heated probe, three impingers containing the

derivatizing reagent in toluene, an empty

impinger, an impinger containing charcoal

and an impinger containing silica gel.

2.2 The impinger contents are

concentrated to dryness under vacuum,

brought to volume with acetonitrile (ACN)

and analyzed with a high pressure liquid

chromatograph (HPLC).

3.0 Definitions. Not Applicable.

4.0 Interferences.

4.1 The greatest potential for interference

comes from an impurity in the derivatizing

reagent, 1-(2-pyridyl)piperazine (1,2-PP).

This compound may interfere with the

resolution of MI from the peak attributed to

unreacted 1,2-PP.

4.2 Other interferences that could result

in positive or negative bias are; (1) alcohols

that could compete with the 1,2-PP for

reaction with an isocyanate; and (2) other

compounds that may coelute with one or

more of the derivatized isocyanates.

4.3 Method interferences may be caused

by contaminants in solvents, reagents,

glassware, and other sample processing

hardware. All these materials must be

routinely shown to be free from interferences

under conditions of the analysis by preparing

and analyzing laboratory method (or reagent)

blanks.

4.3.1 Glassware must be cleaned

thoroughly before using. The glassware

should be washed with laboratory detergent

in hot water followed by rinsing with tap

water and distilled water. The glassware may

be cleaned by baking in a glassware oven at

400 °C for at least one hour. After the

glassware has cooled, the glassware should

be rinsed three times with methylene

chloride and three times with acetonitrile.

Volumetric glassware should not be heated to

400 °C. Instead, after washing and rinsing,

volumetric glassware may be rinsed with

ACN followed by methylene chloride and

allowed to dry in air.

4.3.2 The use of high purity reagents and

solvents helps to reduce interference

problems in sample analysis.

5.0 Safety.

5.1 The toxicity of each reagent has been

precisely defined. Each isocyanate can

produce dangerous levels of hydrogen

cyanide (HCN). The exposure to these

chemicals must be reduced to the lowest

possible level by whatever means available.

The laboratory is responsible for maintaining

a current awareness file of Occupational

Safety and Health Administration (OSHA)

regulations regarding safe handling of the

chemicals specified in this method. A

reference file of material safety data sheets

should also be made available to all

personnel involved in the chemical analysis.

Additional references to laboratory safety are

available.

6.0 Equipment and Supplies.

6.1 Sample Collection. The following

items are required for sample collection:

6.1.1 A schematic of the sampling train

used in this method is shown in Figure 207–

1. This sampling train configuration is

adapted from EPA Method 5 procedures, and,

as such, most of the required equipment is

identical to that used in EPA Method 5

determinations. The only new component

required is a condenser coil.

6.1.2 Construction details for the basic

train components are given in APTD–0581

(see Martin, 1971, in Section 16.0,

References); commercial models of this

equipment are also available. Additionally,

the following subsections list changes to

APTD–0581 and identify allowable train

configuration modifications.

6.1.3 Basic operating and maintenance

procedures for the sampling train are

described in APTD–0576 (see Rom, 1972, in

Section 16.0, References). As correct usage is

important in obtaining valid results, all users
Federal Register / Vol. 62, No. 235 / Monday, December 8, 1997 / Proposed Rules 64535

should refer to APTD–0576 and adopt the

operating and maintenance procedures

outlined therein unless otherwise specified.

The sampling train consists of the

components detailed below.

6.1.3.1 Probe Nozzle. Glass with sharp,

tapered (30° angle) leading edge. The taper

shall be on the outside to preserve a constant

internal diameter. The nozzle shall be

buttonhook or elbow design. A range of

nozzle sizes suitable for isokinetic sampling

should be available in increments of 0.16 cm

(1⁄16 in.), e.g., 0.32–1.27 cm (1⁄8–1⁄2 in.), or

larger if higher volume sampling trains are

used. Each nozzle shall be calibrated

according to the procedures outlined in

Paragraph 10.1.

6.1.3.2 Probe liner. Borosilicate or quartzglass tubing with a heating system capable of

maintaining a probe gas temperature of

120±14 °C (248±25 °F) at the exit end during

sampling. (The tester may opt to operate the

equipment at a temperature lower than that

specified.) Because the actual temperature at

the outlet of the probe is not usually

monitored during sampling, probes

constructed according to APTD–0581 and

using the calibration curves of APTD–0576

(or calibrated according to the procedure

outlined in APTD–0576) are considered

acceptable. Either borosilicate or quartz glass

probe liners may be used for stack

temperatures up to about 480 °C (900 °F).

Quartz glass liners shall be used for

temperatures between 480 and 900 °C (900

and 1650 °F). (The softening temperature for

borosilicate is 820 °C (1508 °F), and for

quartz glass 1500 °C (2732 °F).) Water-cooling

of the stainless steel sheath will be necessary

at temperatures approaching and exceeding

500 °C.

6.1.3.3 Pitot tube. Type S, as described in

Section 2.1 of promulgated EPA Method 2 or

other appropriate devices (see Vollaro, 1976

in Section 16.0, References). The pitot tube

shall be attached to the probe to allow

constant monitoring of the stack-gas velocity.

The impact (high-pressure) opening plane of

the pitot tube shall be even with or above the

nozzle entry plane (see EPA Method 2, Figure

2–6b) during sampling. The Type S pitot tube

assembly shall have a known coefficient,

determined as outlined in Section 4.0 of

promulgated EPA Method 2.

6.1.3.4 Differential Pressure Gauge.

Inclined manometer or equivalent device as

described in Section 2.2 of promulgated EPA

Method 2. One manometer shall be used for

velocity-head (delta P) readings and the other

for orifice differential pressure (delta H)

readings.

6.1.3.5 Impinger Train. Six 500 mL

impingers are connected in series with leakfree ground-glass joints following

immediately after the heated probe. The first

impinger shall be of the Greenburg-Smith

design with the standard tip. The remaining

five impingers shall be of the modified

Greenburg-Smith design, modified by

replacing the tip with a 1.3-cm (1⁄2-in.) I.D.

glass tube extending about 1.3 cm (1⁄2 in.)

from the bottom of the outer cylinder. The

first, second and third impingers shall

contain known quantities of the derivatizing

reagent in toluene with the first impinger

containing 300 mL and 200 mL in the second

and third. The fourth impinger remains

empty. The fifth impinger is filled with a

known amount (2⁄3 full) of activated charcoal

and the sixth with a known amount of

desiccant. A water-jacketed condenser is

placed between the outlet of the first

impinger and the inlet to the second

impinger to reduce the evaporation of

toluene from the first impinger.

6.1.3.6 Metering System. The necessary

components are a vacuum gauge, leak-free

pump, temperature sensors capable of

measuring temperature to within 3 °C (5.4

°F), dry-gas meter capable of measuring

volume to within 1%, and related equipment,

as shown in Figure 207–1. At a minimum,

the pump should be capable of four cubic

feet per minute (cfm) free flow, and the drygas meter should have a recording capacity

of 0–999.9 cubic feet (cu ft) with a resolution

of 0.005 cu ft. Other metering systems

capable of maintaining sampling rates within

10% of isokineticity and of determining

sample volumes to within 2% may be used.

The metering system must be used with a

pitot tube to enable checks of isokinetic

sampling rates. Sampling trains using

metering systems designed for flow rates

higher than those described in APTD–0581

and APTD–0576 may be used, if the

specifications of this method are met.

6.1.3.7 Barometer. Mercury, aneroid, or

other barometer capable of measuring

atmospheric pressure to within 2.5 mm Hg

(0.1 in. Hg). Often the barometric reading

may be obtained from a nearby National

Weather Service station, in which case the

station value (which is the absolute

barometric pressure) is requested and an

adjustment for elevation differences between

the weather station and sampling point is

applied at a rate of minus 2.5 mm Hg (0.1 in.

Hg) per 30-m (100 ft) elevation increase (vice

versa for elevation decrease).

6.1.3.8 Gas density determination

equipment. Temperature sensor and pressure

gauge (as described in Sections 2.3 and 2.4

of EPA Method 2, and gas analyzer, if

necessary (as described in EPA Method 3).

The temperature sensor ideally should be

permanently attached to the pitot tube or

sampling probe in a fixed configuration such

that the tip of the sensor extends beyond the

leading edge of the probe sheath and does not

touch any metal. Alternatively, the sensor

may be attached just before use in the field.

Note, however, that if the temperature sensor

is attached in the field, the sensor must be

placed in an interference-free arrangement

with respect to the Type S pitot tube

openings (see promulgated EPA Method 2,

Figure 2–7. As a second alternative, if a

difference of no more than 1% in the average

velocity measurement is to be introduced, the

temperature sensor need not be attached to

the probe or pitot tube.

6.1.3.9 Calibration/Field-Preparation

Record. A permanent bound laboratory

notebook, in which duplicate copies of data

may be made as they are being recorded, is

required for documenting and recording

calibrations and preparation procedures (i.e.,

silica gel tare weights, quality assurance/

quality control check results, dry-gas meter,

and thermocouple calibrations, etc.). The

duplicate copies should be detachable and

should be stored separately in the test

program archives.

6.2 Sample Recovery. The following

items are required for sample recovery:

6.2.1 Probe Liner. Probe and nozzle

brushes; Teflon bristle brushes with

stainless steel wire or Teflon handles are

required. The probe brush shall have

extensions constructed of stainless steel,

Teflon, or inert material at least as long as

the probe. The brushes shall be properly

sized and shaped to brush out the probe liner

and the probe nozzle.

6.2.2 Wash Bottles. Three. Teflon or

glass wash bottles are recommended;

polyethylene wash bottles should not be used

because organic contaminants may be

extracted by exposure to organic solvents

used for sample recovery.

6.2.3 Glass Sample Storage Containers.

Chemically resistant, borosilicate amber glass

bottles, 500-mL or 1,000-mL. Bottles should

be tinted to prevent the action of light on the

sample. Screw-cap liners shall be either

Teflon or constructed to be leak-free and

resistant to chemical attack by organic

recovery solvents. Narrow-mouth glass

bottles have been found to leak less

frequently.

6.2.4 Graduated Cylinder and/or

Balances. To measure impinger contents to

the nearest 1 ml or 1 g. Graduated cylinders

shall have subdivisions not >2 mL.

Laboratory balances capable of weighing to

±0.5 g or better are required.

6.2.5 Plastic Storage Containers. Screwcap polypropylene or polyethylene

containers to store silica gel and charcoal.

6.2.6 Funnel and Rubber Policeman. To

aid in transfer of silica gel or charcoal to

container (not necessary if silica gel is

weighed in field).

6.2.7 Funnels. Glass, to aid in sample

recovery.

6.3 Crushed Ice. Quantities ranging from

10–50 lb may be necessary during a sampling

run, depending on ambient air temperature.

6.4 Stopcock Grease. The use of silicone

grease is not permitted. Silicone grease usage

is not necessary if screw-on connectors and

Teflon sleeves or ground-glass joints are

used.

6.5 Sample Analysis. The following items

are required for sample analysis.

6.5.1 Rotary Evaporator. Buchii Model

EL–130 or equivalent.

6.5.2 1000 ml round bottom flask for use

with a rotary evaporator.

6.5.3 Separatory Funnel. 500-ml or larger,

with Teflon Stopcock.

6.5.4 Glass Funnel. Short stemmed or

equivalent.

6.5.5 Vials. 15-ml capacity with Teflon

lined caps.

6.5.6 Class A Volumetric Flasks. 10-ml

for bringing samples to volume after

concentration.

6.5.7 Filter Paper. Scientific Products

Grade 370 Qualitative or equivalent.

6.5.8 Buchner Funnel. Porcelain with 100

mm ID or equivalent.

6.5.9 Erlenmeyer Flask. 500-ml with side

arm and vacuum source.

6.5.10 HPLC with at least a binary

pumping system capable of a programmed

gradient.
64536 Federal Register / Vol. 62, No. 235 / Monday, December 8, 1997 / Proposed Rules

6.5.11 Column. Alltech Altima C18, 250

mm × 4.6 mm ID, 5μm particle size (or

equivalent).

6.5.12 Guard Column. Alltech Hypersil

ODS C18, 10 mm × 4.6 mm ID, 5μm particle

size (or equivalent).

6.5.13 UV detector at 254 nm.

6.5.14 Data system for measuring peak

areas and retention times.

7.0 Reagents and Standards.

7.1 Sample Collection Reagents.

7.1.1 Charcoal. Activated, 6–16 mesh.

Used to absorb toluene vapors and prevent

them from entering the metering device. Use

once with each train and discard.

7.1.2 Silica Gel. Indicating type, 6–16

mesh. If previously used, dry at 175 °C (350

°F) for 2 hours before using. New silica gel

may be used as received. Alternatively, other

types of desiccants (equivalent or better) may

be used, subject to the approval of the

Administrator.

7.1.3 Impinger Solution. The impinger

solution is prepared in the laboratory by

mixing a known amount of 1-(2-pyridyl)

piperazine (purity 99.5+ %) in toluene (HPLC

grade or equivalent). The actual

concentration of 1,2-PP should be

approximately four times the amount needed

to ensure that the capacity of the derivatizing

solution is not exceeded. This amount shall

be calculated from the stoichiometric

relationship between 1,2-PP and the

isocyanate of interest and preliminary

information about the concentration of the

isocyanate in the stack emissions. A

concentration of 130 μg/ml of 1,2-PP in

toluene can be used as a reference point. This

solution should be prepared in the

laboratory, stored in a refrigerated area away

from light, and used within ten days of

preparation.

7.2 Sample Recovery Reagents.

7.2.1 Toluene. Distilled-in-glass grade is

required for sample recovery and cleanup

(see Note to 7.2.2 below).

7.2.2 Acetonitrile. Distilled-in-glass grade

is required for sample recovery and cleanup.

Note: Organic solvents from metal

containers may have a high residue blank

and should not be used. Sometimes suppliers

transfer solvents from metal to glass bottles;

thus blanks shall be run before field use and

only solvents with a low blank value

(<0.001%) shall be used.

7.3 Reagent grade chemicals should be

used in all tests. All reagents shall conform

to the specifications of the Committee on

Analytical Reagents of the American

Chemical Society, where such specifications

are available.

7.3.1 Toluene, C6H5CH3. HPLC Grade or

equivalent.

7.3.2 Acetonitrile, CH3CN (ACN). HPLC

Grade or equivalent.

7.3.3 Methylene Chloride, CH2CL2. HPLC

Grade or equivalent.

7.3.4 Hexane, C6H14. Pesticide Grade or

equivalent.

7.3.5 Water, H2O. HPLC Grade or

equivalent.

7.3.6 Ammonium Acetate, CH3CO2NH4.

7.3.7 Acetic Acid (glacial), CH3CO2H.

7.3.8 1-(2-Pyridyl) piperazine, (1,2-pp).

Aldrich, 99.5+% or equivalent.

7.3.9 Absorption Solution. Prepare a

solution of 1-(2-pyridyl) piperazine in

toluene at a concentration of 40 mg/300 ml.

This solution is used for method blanks and

method spikes.

7.3.10 Ammonium Acetate Buffer

Solution (AAB). Prepare a solution of

ammonium acetate in water at a

concentration of 0.1 M by transferring 7.705

g of ammonium acetate to a 1000 ml

volumetric flask and diluting to volume with

HPLC Grade water. Adjust pH to 6.2 with

glacial acetic acid.

8.0 Sample Collection, Preservation,

Storage and Transport.

8.1 Because of the complexity of this

method, field personnel should be trained in

and experienced with the test procedures in

order to obtain reliable results.

8.2 Preliminary Field Determinations.

8.2.1 Select the sampling site and the

minimum number of sampling points

according to EPA Method 1 or as specified

by the Administrator. Determine the stack

pressure, temperature, and range of velocity

heads using EPA Method 2. It is

recommended that a leak-check of the pitot

lines (see promulgated EPA Method 2,

Section 3.1) be performed. Determine the

stack gas moisture content using EPA

Approximation Method 4 or its alternatives

to establish estimates of isokinetic samplingrate settings. Determine the stack-gas dry

molecular weight, as described in

promulgated EPA Method 2, Section 3.6. If

integrated EPA Method 3 sampling is used

for molecular weight determination, the

integrated bag sample shall be taken

simultaneously with, and for the same total

length of time as, the sample run.

8.2.2 Select a nozzle size based on the

range of velocity heads so that changing the

nozzle size in order to maintain isokinetic

sampling rates is not necessary. During the

run, do not change the nozzle. Ensure that

the proper differential pressure gauge is

chosen for the range of velocity heads

encountered (see Section 2.2 of promulgated

EPA Method 2).

8.2.3 Select a suitable probe liner and

probe length so that all traverse points can

be sampled. For large stacks, to reduce the

length of the probe, consider sampling from

opposite sides of the stack.

8.2.4 A typical sample volume to be

collected is 1 dscm (35.31 dscf). The sample

volume can be adjusted as required by

analytical detection limit constraints and/or

estimated stack concentrations. A maximum

limit should be determined to avoid

exceeding the capacity of the reagent.

8.2.5 Determine the total length of

sampling time needed to obtain the identified

minimum volume by comparing the

anticipated average sampling rate with the

volume requirement. Allocate the same time

to all traverse points defined by EPA Method

1. To avoid timekeeping errors, the length of

time sampled at each traverse point should

be an integer or an integer plus one-half min.

8.2.6 In some circumstances (e.g., batch

cycles) sampling for shorter times at the

traverse points may be necessary and to

obtain smaller gas-sample volumes. In these

cases, the Administrator’s approval must first

be obtained.

8.3 Preparation of Sampling Train.

8.3.1 During preparation and assembly of

the sampling train, keep all openings where

contamination can occur covered with

Teflon film or aluminum foil until just

before assembly or until sampling is about to

begin.

8.3.2 Place 300 ml of the impinger

absorbing solution in the first impinger and

200 ml each in the second and third

impingers. The fourth impinger shall remain

empty. The fifth and sixth impingers shall

have 400 g of preweighed charcoal and 200–

300 g of silica gel, respectively.

8.3.3 When glass probe liners are used,

install the selected nozzle using a Viton-A

O-ring when stack temperatures are <260 °C

(500 °F) and a woven glass-fiber gasket when

temperatures are higher. See APTD–0576

(Rom, 1972) for details. Other connecting

systems using Teflon ferrules may be used.

Mark the probe with heat-resistant tape or by

another method to denote the proper distance

into the stack or duct for each sampling

point.

8.3.4 Set up the train as shown in Figure

207–1. During assembly, do not use any

silicone grease on ground-glass joints.

Connect all temperature sensors to an

appropriate potentiometer/display unit.

Check all temperature sensors at ambient

temperature.

8.3.5 Place crushed ice around the

impingers.

8.3.6 Turn on the condenser coil coolant

recirculating pump and begin monitoring the

gas entry temperature. Ensure proper gas

entry temperature before proceeding and

again before any sampling is initiated. It is

important that the gas entry temperature not

exceed 50 °C (122 °F), thus reducing the loss

of toluene from the first impinger.

8.3.7 Turn on and set the probe heating

systems at the desired operating

temperatures. Allow time for the temperature

to stabilize.

8.4 Leak-Check Procedures.

8.4.1 Pre-test leak-check.

8.4.1.1 Because the additional connection

in the train (over the EPA Method 5 Train)

increases the possibility of leakage, a pre-test

leak-check is required.

8.4.1.2 After the sampling train has been

assembled, turn on and set the probe heating

systems at the desired operating

temperatures. Allow time for the

temperatures to stabilize. If a Viton A O-ring

or other leak-free connection is used in

assembling the probe nozzle to the probe

liner, leak-check the train at the sampling site

by plugging the nozzle and pulling a 381-mm

Hg (15-in. Hg) vacuum. Leakage rates greater

than 4% of the average sampling rate or

>0.00057 m3/min (0.020 cfm), whichever is

less, are unacceptable.

Note: A lower vacuum may be used, if it

is not exceeded during the test.

8.4.1.3 The following leak-check

instructions for the sampling train described

in APTD–0576 and APTD–0581 may be

helpful. Start the pump with the fine-adjust

valve fully open and the coarse-adjust valve

completely closed. Partially open the coarseadjust valve and slowly close the fine-adjust

valve until the desired vacuum is reached.

Do not reverse direction of the fine-adjust

valve; this will cause impinger contents to

back up in the train. If the desired vacuum

is exceeded, either leak-check at this higher
Federal Register / Vol. 62, No. 235 / Monday, December 8, 1997 / Proposed Rules 64537

vacuum or end the leak-check, as shown

below, and start over.

8.4.1.4 When the leak-check is

completed, first slowly remove the plug from

the inlet to the probe. When the vacuum

drops to 127 mm (5 in.) Hg or less,

immediately close the coarse-adjust valve.

Switch off the pumping system and reopen

the fine-adjust valve. Do not reopen the fineadjust valve until the coarse-adjust valve has

been closed. This prevents the reagent in the

impingers from being forced backward into

the probe and silica gel from being entrained

backward into the fifth impinger.

8.4.2 Leak-Checks During Sampling Run.

8.4.2.1 If, during the sampling run, a

component change becomes necessary, a

leak-check shall be conducted immediately

after the interruption of sampling and before

the change is made. The leak-check shall be

done according to the procedure outlined in

Paragraph 8.4.1, except that it shall be done

at a vacuum greater than or equal to the

maximum value recorded up to that point in

the test. If the leakage rate is no greater than

0.00057 m3/min (0.020 cfm) or 4% of the

average sampling rate (whichever is less), the

results are acceptable, and no correction will

need to be applied to the total volume of dry

gas metered. If a higher leakage rate is

obtained, the tester shall void the sampling

run.

Note: Any ‘‘correction’’ of the sample

volume by calculation reduces the integrity

of the pollutant concentration data generated

and must be avoided.

8.4.2.2 Immediately after a component

change, and before sampling is restarted, a

leak-check similar to a pre-test leak-check

must also be conducted.

8.4.3 Post-Test Leak-Check.

8.4.3.1 A leak-check of the sampling train

is mandatory at the conclusion of each

sampling run. The leak-check shall be

performed with the same procedures as those

with the pre-test leak-check, except that it

shall be conducted at a vacuum greater than

or equal to the maximum value reached

during the sampling run. If the leakage rate

is no greater than 0.00057 m3/min (0.020

cfm) or 4% of the average sampling rate

(whichever is less), the results are acceptable,

and no correction need be applied to the total

volume of dry gas metered. If, however, a

higher leakage rate is obtained, the tester

shall either record the leakage rate, correct

the sample volume (as shown in Section 6.3

of Method 5), and consider the data obtained

of questionable reliability, or void the

sampling run.

8.5 Sampling-Train Operation.

8.5.1 During the sampling run, maintain

an isokinetic sampling rate to within 10% of

true isokinetic, unless otherwise specified by

the Administrator.

8.5.2 For each run, record the data

required on a data sheet such as the one

shown in Figure 207–2. Be sure to record the

initial dry-gas meter reading. Record the drygas meter readings at the beginning and end

of each sampling time increment, when

changes in flow rates are made before and

after each leak-check, and when sampling is

halted. Take other readings shown by Figure

207–2 at least once at each sample point

during each time increment and additional

readings when significant changes (20%

variation in velocity-head readings) require

additional adjustments in flow rate. Level

and zero the manometer. Because the

manometer level and zero may drift due to

vibrations and temperature changes, make

periodic checks during the traverse.

8.5.3 Clean the stack access ports before

the test run to eliminate the chance of

collecting deposited material. To begin

sampling, verify that the probe heating

system is at the specified temperature,

remove the nozzle cap, and verify that the

pitot tube and probe are properly positioned.

Position the nozzle at the first traverse point,

with the tip pointing directly into the gas

stream. Immediately start the pump and

adjust the flow to isokinetic conditions.

Nomographs, which aid in the rapid

adjustment of the isokinetic sampling rate

without excessive computations, are

available. These nomographs are designed for

use when the Type S pitot-tube coefficient is

0.84±0.02 and the stack-gas equivalent

density (dry molecular weight) is equal to

29±4. APTD–0576 details the procedure for

using the nomographs. If the stack-gas

molecular weight and the pitot-tube

coefficient are outside the above ranges, do

not use the nomographs unless appropriate

steps (Shigehara, 1974, in Section 16.0,

References) are taken to compensate for the

deviations.

8.5.4 When the stack is under significant

negative pressure (equivalent to the height of

the impinger stem), take care to close the

coarse-adjust valve before inserting the probe

into the stack, to prevent the impinger

solutions from backing into the probe. If

necessary, the pump may be turned on with

the coarse-adjust valve closed.

8.5.5 When the probe is in position, block

off the openings around the probe and stack

access port to prevent unrepresentative

dilution of the gas stream.

8.5.6 Traverse the stack cross section, as

required by EPA Method 1 or as specified by

the Administrator, being careful not to bump

the probe nozzle into the stack walls when

sampling near the walls or when removing or

inserting the probe through the access port,

in order to reduce the chance of extracting

deposited material.

8.5.7 During the test run, make periodic

adjustments to keep the temperature of the

condenser at the proper levels; add more ice

and, if necessary, salt to maintain the

temperature. Also, periodically check the

level and zero of the manometer.

8.5.8 A single train shall be used for the

entire sample run, except in cases where

simultaneous sampling is required in two or

more separate ducts or at two or more

different locations within the same duct, or

in cases where equipment failure requires a

change of trains. In all other situations, the

use of two or more trains will be subject to

the approval of the Administrator.

8.5.9 At the end of the sample run, close

the coarse-adjust valve, remove the probe and

nozzle from the stack, turn off the pump,

record the final dry-gas meter reading, and

conduct a post-test leak-check. Also, leakcheck the pitot lines as described in EPA

Method 2. The lines must pass this leakcheck in order to validate the velocity-head

data.

8.5.10 Calculate percent isokineticity (see

Section 6.11 of Method 5) to determine

whether the run was valid or another test run

should be performed.

8.6 Sample Recovery.

8.6.1 Preparation.

8.6.1.1 Proper cleanup procedure begins

as soon as the probe is removed from the

stack at the end of the sampling period.

Allow the probe to cool. When the probe can

be handled safely, wipe off all external

particulate matter near the tip of the probe

nozzle and place a cap over the tip to prevent

losing or gaining particulate matter. Do not

cap the probe tip tightly while the sampling

train is cooling down because this will create

a vacuum in the train.

8.6.1.2 Before moving the sample train to

the cleanup site, remove the probe from the

sample train and cap the open outlet, being

careful not to lose any condensate that might

be present. Cap the impinger inlet. Remove

the umbilical cord from the last impinger and

cap the impinger.

8.6.1.3 Transfer the probe and the

impinger/condenser assembly to the cleanup

area. This area should be clean and protected

from the weather to reduce sample

contamination or loss.

8.6.1.4 Save a portion of all washing

solutions (toluene/acetonitrile) used for the

cleanup as a blank. Transfer 200 ml of each

solution directly from the wash bottle being

used and place each in a separate, prelabeled

glass sample container.

8.6.1.5 Inspect the train prior to and

during disassembly and note any abnormal

conditions.

8.6.2 Sample Containers.

8.6.2.1 Container No. 1. With the aid of

an assistant, rinse the probe/nozzle first with

toluene and then with acetonitrile by tilting

and rotating the probe while squirting the

solvent into the upper end of the probe so

that all of the surfaces are wetted with

solvent. When using these solvents insure

that proper ventilation is available. Let the

solvent drain into the container. If particulate

is visible, use a Teflon brush to loosen/

remove the particulate and follow with a

second rinse of each solvent. After weighing

the contents of the first impinger, add it to

container No. 1 along with the toluene and

acetonitrile rinses of the impinger.

(Acetonitrile will always be the final rinse.)

If two liquid layers are present add both to

the container. After all components have

been collected in the container, seal the

container, mark the liquid level on the bottle

and add the proper label.

8.6.2.2 Container No. 2. After weighing

the contents of the second, third and fourth

impingers, add them to container No. 2 along

with the toluene and acetonitrile rinses of the

impingers, the condenser and all connecting

glassware. After all components have been

collected in the container, seal the container,

mark the liquid level on the bottle and add

the proper label.

8.6.3 The contents of the fifth and sixth

impingers (charcoal and silica gel) can be

discarded after they have been weighed.

8.6.4 Sample Preparation for Shipment.

Prior to shipment, recheck all sample

containers to ensure that the caps are well

secured. Seal the lids with Teflon tape. Ship
64538 Federal Register / Vol. 62, No. 235 / Monday, December 8, 1997 / Proposed Rules

all samples upright, packed in ice, using the

proper shipping materials as prescribed for

hazardous materials. The samples must be

stored at 4°C between the time of sampling

and concentration. Each sample should be

extracted and concentrated within 30 days

after collection and analyzed within 30 days

after extraction. The extracted sample must

be stored at 4°C.

9.0 Quality Control.

9.1 Sampling. See EPA Manual 600/4–

77–027b for Method 5 quality control.

9.1.1 Field Blanks. Field blanks must be

submitted with the samples collected at each

sampling site. The field blanks include the

sample bottles containing aliquots of sample

recovery solvents, and impinger solutions. At

a minimum, one complete sampling train

will be assembled in the field staging area,

taken to the sampling area, and leak-checked

at the beginning and end of the testing (or for

the same total number of times as the actual

test train). The probe of the blank train shall

be heated during the sample test. The train

will be recovered as if it were an actual test

sample. No gaseous sample will be passed

through the sampling train.

9.1.2 Reagent Blanks. An aliquot of

toluene, acetonitrile and the impinger

solution will be collected in the field as

separate samples and returned to the

laboratory for analysis to evaluate artifacts

that may be observed in the actual samples.

9.2 Analysis.

9.2.1 The correlation coefficient for the

calibration curve must be 0.995 or greater. If

the correlation coefficient is less than 0.995,

the HPLC system should be examined for

problems, and a new calibration curve

should be prepared and analyzed.

9.2.2 A solvent blank should be analyzed

daily to verify that the system is not

contaminated.

9.2.3 A calibration standard should be

analyzed prior to any samples being

analyzed, after every 10 injections and at the

end of the sample set. Samples must be

bracketed by calibration standards that have

a response that does not vary by more than

10% of the target value. If the calibration

standards are outside the limit, the samples

must be reanalyzed after it is verified that the

analytical system is in control.

9.2.4 A method blank should be prepared

and analyzed for every 10 samples

concentrated (Section 11.4).

9.2.5 A method spike should be prepared

and analyzed for every 20 samples. The

response for each analyte should be within

20% of the expected theoretical value of the

method spike (Section 11.3).

10.0 Calibration and Standardization.

Note: Maintain a laboratory log of all

calibrations.

10.1 Probe Nozzle. Probe nozzles shall be

calibrated before their initial use in the field.

Using a micrometer, measure the inside

diameter of the nozzle to the nearest 0.025

mm (0.001 in.). Make measurements at three

separate places across the diameter and

obtain the average of the measurements. The

difference between the high and low

numbers shall not exceed 0.1 mm (0.004 in.).

When nozzles become nicked, dented, or

corroded, they shall be reshaped, sharpened,

and recalibrated before use. Each nozzle shall

be permanently and uniquely identified.

10.2 Pitot Tube Assembly. The Type S

pitot tube assembly shall be calibrated

according to the procedure outlined in

Section 4 of promulgated EPA Method 2, or

assigned a nominal coefficient of 0.84 if it is

not visibly nicked, dented, or corroded and

if it meets design and intercomponent

spacing specifications.

10.3 Metering System.

10.3.1 Before its initial use in the field,

the metering system shall be calibrated

according to the procedure outlined in

APTD–0576. Instead of physically adjusting

the dry-gas meter dial readings to correspond

to the wet-test meter readings, calibration

factors may be used to correct the gas meter

dial readings mathematically to the proper

values. Before calibrating the metering

system, it is suggested that a leak-check be

conducted. For metering systems having

diaphragm pumps, the normal leak-check

procedure will not detect leakages within the

pump. For these cases the following leakcheck procedure is suggested: Make a 10-min

calibration run at 0.00057 m3/min (0.020

cfm); at the end of the run, take the difference

of the measured wet-test and dry-gas meter

volumes and divide the difference by 10 to

get the leak rate. The leak rate should not

exceed 0.00057 m3/min (0.020 cfm).

10.3.2 After each field use, the calibration

of the metering system shall be checked by

performing three calibration runs at a single

intermediate orifice setting (based on the

previous field test). The vacuum shall be set

at the maximum value reached during the

test series. To adjust the vacuum, insert a

valve between the wet-test meter and the

inlet of the metering system. Calculate the

average value of the calibration factor. If the

calibration has changed by more than 5%,

recalibrate the meter over the full range of

orifice settings, as outlined in APTD–0576.

10.3.3 Leak-check of metering system.

That portion of the sampling train from the

pump to the orifice meter (see Figure 207–

1) should be leak-checked prior to initial use

and after each shipment. Leakage after the

pump will result in less volume being

recorded than is actually sampled. Close the

main valve on the meter box. Insert a onehole rubber stopper with rubber tubing

attached into the orifice exhaust pipe.

Disconnect and vent the low side of the

orifice manometer. Close off the low side

orifice tap. Pressurize the system to 13–18 cm

(5–7 in.) water column by blowing into the

rubber tubing. Pinch off the tubing and

observe the manometer for 1 min. A loss of

pressure on the manometer indicates a leak

in the meter box. Leaks, if present, must be

corrected.

Note: If the dry-gas-meter coefficient values

obtained before and after a test series differ

by >5%, either the test series shall be voided

or calculations for test series shall be

performed using whichever meter coefficient

value (i.e., before or after) gives the lower

value of total sample volume.

10.4 Probe Heater. The probe-heating

system shall be calibrated before its initial

use in the field according to the procedure

outlined in APTD–0576. Probes constructed

according to APTD–0581 need not be

calibrated if the calibration curves in APTD–

0576 are used.

10.5 Temperature Sensors. Each

thermocouple must be permanently and

uniquely marked on the casing; all mercuryin-glass reference thermometers must

conform to ASTM E–1 63 specifications.

Thermocouples should be calibrated in the

laboratory with and without the use of

extension leads. If extension leads are used

in the field, the thermocouple readings at

ambient air temperatures, with and without

the extension lead, must be noted and

recorded. Correction is necessary if the use

of an extension lead produces a change

>1.5%.

10.5.1 Dry-gas meter thermocouples. For

the thermocouples used to measure the

temperature of the gas leaving the impinger

train three-point calibration at ice-water,

room-air, and boiling-water temperatures is

necessary. Accept the thermocouples only if

the readings at all three temperatures agree

to ±2°C (3.6°F) with those of the absolute

value of the reference thermometer.

10.5.2 Probe and stack thermocouples.

For the thermocouples used to indicate the

probe and stack temperatures, a three-point

calibration at ice-water, boiling-water, and

hot-oil-bath temperatures must be performed;

it is recommended that room-air temperature

be added, and that the thermometer and the

thermocouple agree to within 1.5% at each

of the calibration points. A calibration curve

(equation) may be constructed (calculated)

and the data extrapolated to cover the entire

temperature range suggested by the

manufacturer.

10.6 Barometer. Adjust the barometer

initially and prior to each test series to agree

to within ±2.5 mm Hg (0.1 in. Hg) of the

mercury barometer or the corrected

barometric pressure value reported by a

nearby National Weather Service Station

(same altitude above sea level).

10.7 Balance. Calibrate the balance before

each test series, using Class-S standard

weights; the weights must be within ±0.5%

of the standards, or the balance must be

adjusted to meet these limits.

10.8 High Performance Liquid

Chromatograph. Establish the retention times

for each of the isocyanates of interest using

the chromatographic conditions provided in

Section 11.5.1. The retention times provided

in Table 11.5.1–1 are provided as a guide to

relative retention times. Prepare derivatized

calibration standards (concentrations

expressed in terms of the free isocyanate,

Section 12.4) according to the procedure in

Section 10.8.1. Calibrate the chromatographic

system using the external standard technique

(Section 10.8.2)

10.8.1 Preparation of calibration

standards. Prepare a 100 μg/ml stock solution

of the isocyanates of interest from the

individual isocyanate-urea derivative as

prepared in Sections 11.1.1 and 11.1.2. This

is accomplished by dissolving 1 mg of each

isocyanate-urea derivative in 10 ml of ACN.

Calibration standards are prepared from this

stock solution by making appropriate

dilutions of aliquots of the stock into ACN.

Calibrate the instrument from 1 to 20 μg/ml

for HDI, TDI and MDI, and from 1 to 80 μg/

ml for MI using at least six calibration points.

10.8.2 External standard calibration

procedure. Analyze each derivatized
Federal Register / Vol. 62, No. 235 / Monday, December 8, 1997 / Proposed Rules 64539

calibration standard using the

chromatographic conditions listed in Section

11.5.1 and tabulate peak area against

concentration injected. The working

calibration curve must be verified on each

working day by the measurement of one or

more calibration standards. If the response

for any analyte varies from the target

response by more than 10%, the test must be

repeated using a fresh calibration standard(s)

after it is verified that the analytical system

is under control. Alternatively, a new

calibration curve may be prepared for that

compound.

11.0 Analytical Procedure.

11.1 Preparation of isocyanate

derivatives.

11.1.1 HDI, TDI, MDI.

11.1.1.1 Dissolve 500 mg of each

isocyanate in individual 100 ml aliquots of

MeCl2, except MDI which requires 250 ml of

MeCl2. Transfer a 5-ml aliquot of 1,2-pp (see

Section 7.3.8) to each solution, stir and allow

to stand overnight at room temperature.

Transfer 150 ml aliquots of hexane to each

solution to precipitate the isocyanate-urea

derivative. Using a Buchner funnel, vacuum

filter the solid-isocyanate-urea derivative and

wash with 50 ml of hexane. Dissolve the

precipitate in a minimum aliquot of MeCl2.

Repeat the hexane precipitation and filtration

twice. After the third filtration, dry the

crystals at 50 °C and transfer to bottles for

storage. The crystals are stable for at least 21

months when stored at room temperature in

a closed container.

11.1.2 MI.

11.1.2.1 To prepare a 200 μg/ml stock

solution of methyl isocyanate-urea, transfer

60 mg of 1,2-pp to a 100-ml volumetric flask

containing 50 ml of MeCl2. Carefully transfer

20 mg of methyl isocyanate to the volumetric

flask and shake for 2 minutes. Dilute the

solution to volume with MeCl2 and transfer

to a bottle for storage. Methyl isocyanate does

not produce a solid derivative and standards

must be prepared from this stock solution.

11.2 Concentration of Samples.

11.2.1 Transfer each sample to a 1000-ml

round bottom flask. Attach the flask to a

rotary evaporator and gently evaporate to

dryness under vacuum in a 65 °C water bath.

Rinse the round bottom flask three times

each with two ml of ACN and transfer the

rinse to a 10-ml volumetric flask. Dilute the

sample to volume with ACN and transfer to

a 15-ml vial and seal with a Teflon lined

lid. Store the vial at 4 °C until analysis.

11.3 Preparation of Method Spikes.

11.3.1 Prepare a method spike for every

twenty samples. Transfer 300 ml of the

absorption solution to a 1000-ml round

bottom flask. Transfer 1 ml of a 100 μg/ml

standard containing the isocyanate-urea

derivatives of interest. Follow the procedure

outlined in Section 11.2.1 for sample

concentration. This will result in a method

spike with a theoretical concentration of 10

μg/ml.

11.4 Preparation of Method Blanks.

11.4.1 Prepare a method blank for every

ten samples by transferring 300 ml of the

absorption solution to a 1000-ml round

bottom flask and concentrate as outlined in

Section 11.2.1.

11.5 Chromatographic Analysis.

11.5.1 Chromatographic Conditions.

Column .............. C18, 250 mm x 4.6 mm

ID, 5μm particle size.

Mobile Phase ..... Acetonitrile/Ammonium

Acetate Buffer.

Gradient ............. 10:90 (v/v) ACN:AAB to

60:40 (v/v) ACN:AAB

over 30 minutes.

Flow Rate ........... 2 ml/min.

UV Detector ....... 254 nm.

Injection Volume 50 μl.

11.5.2 Analysis.

11.5.2.1 Analyze samples by HPLC, using

conditions established in Section 11.5.1.

11.5.2.2 The width of the retention time

window used to make identifications should

be based upon measurements of actual

retention time variations of standards over

the course of a day.

Three times the standard deviation of a

retention time for a compound can be used

to calculate a suggested window size;

however, the experience of the analyst

should weigh heavily in the interpretation of

the chromatograms.

11.5.2.3 If the peak area exceeds the

linear range of the calibration curve, the

sample should be diluted with ACN and

reanalyzed.

12.0 Data Analysis and Calculations.

Same as in Method 5, Section 6, with the

following additions.

12.1 Perform Calculations. Round off

figures after the final calculation to the

correct number of significant figures.

12.2 Nomenclature. Same as Method 5,

Section 6.1 with the following additions:

AS = Response of the sample, area counts.

b = Y-intercept of the linear regression line,

area counts.

CI = Concentration of a specific isocyanate

compound in the sample, μg/ml.

M = Slope of the linear regression line, area

counts-ml/μg.

mI = Mass of isocyanate in the total sample.

VF = Final volume of concentrated sample,

typically 10 ml.

Amount of the

isocyanate-urea

Amount of

cyanate

Molecular weight of the isocyanate-urea

Molecular weight of the isocyanate = ∗ Eq. 207-1 



 



 free iso

Vm(std) = Volume of gas sample measured by

the dry-gas meter, corrected to standard

conditions, dscm (dscf).

12.3 Conversion from isocyanate to the

isocyanate-urea derivative. The equation for

converting the amount of free isocyanate to

the corresponding amount of isocyanate-urea

derivative is as follows:

The equation for converting the amount of isocyanate-urea derivative to the corresponding amount of free isocyanate is as follows:

Amount of

the isocyanate

Amount of

isocyanateMolecular weight of the isocyanate

Molecular weight of the isocyanate-urea = ∗ Eq. 207-2 



 



 urea

12.4 Calculate the correlation coefficient,

slope, and intercepts for the calibration data

using the least squares method for linear

regression. Concentrations are expressed as

the x-variable and response is expressed as

the y-variable.

12.5 Calculate the concentration of

isocyanate in the sample:

C

A b

M I

s = ( ) − Eq. 207-3

12.6 Calculate the total amount collected

in the sample by multiplying the

concentration (μg/ml) times the final volume

of ACN (10 ml).

m C V I I F = Eq. 207-4

12.7 Calculate the concentration of

isocyanate (μg/dscm) in the stack gas.

C K m

V S

I

m std

=

( )

Eq. 207-5

Where:

K = 35.31 ft3/m3 if Vm(std) is expressed in

English units.

= 1.00 m3/m3 if Vm(std) is expressed in metric

units.

13.0 Method Performance.

13.1 Method Performance Evaluation.

Evaluation of analytical procedures for a

selected series of compounds must include

the sample-preparation procedures and each

associated analytical determination. The

analytical procedures should be challenged

by the test compounds spiked at appropriate

levels and carried through the procedures.

13.2 Method Detection Limit. The overall

method detection limits (lower and upper)

must be determined on a compound-by64540 Federal Register / Vol. 62, No. 235 / Monday, December 8, 1997 / Proposed Rules

compound basis because different

compounds may exhibit different collection,

retention, and extraction efficiencies as well

as the instrumental minimum detection limit

(MDL). The method detection limit must be

quoted relative to a given sample volume.

The upper limits for the method must be

determined relative to compound retention

volumes (breakthrough). Method Detection

Limits may vary due to matrix effects and

instrument conditions.

13.3 Method Precision and Bias. The

overall method precision and bias must be

determined on a compound-by-compound

basis at a given concentration level. The

method precision value would include a

combined variability due to sampling,

sample preparation, and instrumental

analysis. The method bias would be

dependent upon the collection, retention,

and extraction efficiency of the train

components. From evaluation studies to date

using a dynamic spiking system, acceptable

method biases (per EPA Method 301) have

been determined for all four isocyanates. A

precision of less than 10% relative standard

deviation (RSD) has been calculated from

field test data sets which resulted from a

series of paired, unspiked and spiked trains.

14.0 Pollution Prevention. Not

Applicable.

15.0 Waste Management. Not Applicable.

16.0 References.

1. Martin, R.M., Construction Details of

Isokinetic Source-Sampling Equipment,

Research Triangle Park, NC, U.S.

Environmental Protection Agency, April

1971, PB–203 060/BE, APTD–0581, 35 pp.

2. Rom, J.J., Maintenance, Calibration, and

Operation of Isokinetic Source Sampling

Equipment, Research Triangle Park, NC, U.S.

Environmental Protection Agency, March

1972, PB–209 022/BE, APTD–0576, 39 pp.

3. Schlickenrieder, L.M., Adams, J.W., and

Thrun, K.E., Modified Method 5 Train and

Source Assessment Sampling System:

Operator’s Manual, U.S. Environmental

Protection Agency, EPA/600/8–85/003

(1985).

4. Shigehara, R.T., Adjustments in the EPA

Nomograph for Different Pitot Tube

Coefficients and Dry Molecular Weights,

Stack Sampling News, 2:4–11 (October 1974).

5. U.S. Environmental Protection Agency,

40 CFR Part 60, Appendix A, Methods 1–5.

6. Vollaro, R.F., A Survey of Commercially

Available Instrumentation for the

Measurement of Low-Range Gas Velocities,

Research Triangle Park, NC, U.S.

Environmental Protection Agency, Emissions

Measurement Branch, November 1976

(unpublished paper).

17.0 Tables, Diagrams, Flowcharts, and

Validation Data.

TABLE 1.—MOLECULAR WEIGHT OF

THE FREE ISOCYANATES AND THE

ISOCYANATE-UREA DERIVATIVE

Analyte MW (free

Isocyanate)

MW (Derivative)

1,6–HDI .................. 168 494.44

2,4–TD .................... 174.16 500.56

MDI ......................... 250.25 576.65

TABLE 2.—MOLECULAR WEIGHT OF

FREE METHYL ISOCYANATE AND

METHYL ISOCYANATE-UREA DERIVATIVE

Analyte MW (free

Isocyanate)

MW (Derivative)

MI ............................ 57.1 220.32

TABLE 3.—RETENTION TIMES OF THE

FOUR ISOCYANATES

Compound

Retention

time

(minutes)

MI .................................................. 10.0

1,6–HDI ......................................... 19.9

2,4–TDI ......................................... 27.1

MDI ............................................... 27.3

BILLING CODE 6560–50–P
Federal Register / Vol. 62, No. 235 / Monday, December 8, 1997 / Proposed Rules 64541
64542 Federal Register / Vol. 62, No. 235 / Monday, December 8, 1997 / Proposed Rules

[FR Doc. 97–32045 Filed 12–5–97; 8:45 am]

BILLING CODE 6560–50–C