# FEDERAL REGISTER

VOLUME 36

- NUMBER 84 Friday, April30, 1971 * 

# Washington, D.C. 

# PART Il



# ENVIRONMENTAL PROTECTION AGENCY

National Primaryand Secondary 

# Ambient Air QualityStandards

No.8.--Pt. r-1

## RULES AND REGULATIONS 

# Title 42-PUBLIC HEALTH

ChapterIV-Environmental Protection Agency
PART41O-NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS
Notices of proposedIrule-making published in the FEDERAL REGISTER on January 30, 1971 (36 F.R. 1502) and MVarch 26, 1971 (36 F.R.5867) set forth regulations prescribingnational primary and secondary ambient air quality standards proposed for adoption as Part 410 of 42 CFR. Interested persons were afforded an opportunity to participate in the rule-making by submitting comments. Following review of the proposed standards and consideration ofthe comments, the standards have been revised

as described below and are being promulgated today.

National primary ambient air quality standards are those which, inthe judgment ofthe Administrator, based onthe air qualitycriteria -andallowing an adequate margin of safety, are requisite to protectthe public health.

Nationalsecondary ambient air quality standards arethose which, in the judgmentofthe Administrator, based onthe air quality criteria, arerequisite to protect the public welfare from any known

or anticipated adverse effects associated with the presence of air pollutants in the ambient air.

The comments submitted to the Environmental Protection Agency reflect divergences ofopinion among interested and informed persons as to the proper interpretation of available data on the public health and welfare effects ofthe six pollutants for which national ambient air quality standards are being established. A number of comments question the feasibility of implementing the proposed standards. Because the Clean AirAct,as amended,doesnotpermit any factors other than health to be taken into account in setting -the primary standards, no revisions were made on this basis. In reviewing the proposed standards,the Environmental Protection Agency limited its consideration tocomments concerning the validity of the scientific basis of the standards.

Current scientific, knowledge of the health and welfare hazards ofthese air pollutants is imperfect. To increase and improve this knowledge, the Environmental Protection Agency will continue to conduct and support relevant research. At the same time, the need for increased knowledge of the health and welfare effects of air pollution cannot justify failure to take action based on knowledge presently available. The Clean Air Act, as amended, requires promulgation at this time of national standards for six air pollutants on the basis of available data set forth in air quality criteria documents. Thus, the Administrator is required to make judgments asto the properinterpretation of presently available data andto establish national primary standards which include an adequate margin of safety to protect humanhealth. Where the validity of available research data has been questioned, but not wholly refuted, the Administrator has ineach case promulgateda nationalprimary standardwhich includes a margin of safety adequate to protect the public health from adverse effects suggested by the available data.

The national primary standard for carbon monoxide, proposed on January 30, 1971, was based on evidence that low levels of carboxyhemoglobin in human bloodmaybe associatedwithimpairment of ability to discriminate time intervals. This evidenceisreflected in "Air Quality Criteria for Carbon Monoxide" (35 FR. 4768). In thecomments,seriousquestions

were raised about the soundness of this evidence. Extensive consideration was given to this matter. The conclusions reached werethatthe evidenceregarding impaired time-interval discrimination had not been'refuted and that a lessrestrictive national standard for carbon monoxide would therefore not provide the margin of safety which may be needed to protect the health of persons especially sensitive to the effects of elevated carboxyhemoglobin levels. The only change madeinthenational standards for carbon monoxide was a modification of the 1-hour value. The revised standard affords protection from the

same low levels of blood carboxyhemoglobin as a result of short-term exposure. The national standards for carbon monoxide,, as set forth below, are intended to protect against the occurrence ofcarboxyhemoglobin levels above2percent.It is the Administrator's judgment that attainment of the national standards for carbon monoxide will provide

an adequate safety margin for protection of public health and will protect' against known and anticipated adverse effects on public welfare.

National standards for photochemical oxidants have alsobeen revised. The revised national primary standard of 160 pg./m?.(0.08p.pm.) isbased onevidence of increased frequency of asthma attacks insome asthmatic subjects ondays when estimated hourly average concentrations of photochemical oxidant reached 200pg./m?(0.10p.pm.). Anumber ofcomments raised serious questions about the validity of data used to suggestimpairment of athletic performance at lower oxidant concentrations. The revisedprimarystandardincludes amargin of safety which is substantially below the most likely threshold level suggestedby this data.It isthe Administrator'sjudgment that a primary standard of 160 pg./m? (0.08 p.pm.) as a 1-hour average will provide an adequate safety margin for protection of public health and will protect against known and anticipated adverse effects on public welfare.

National standards for hydrocarbons have been revised to make these standards consistent with the above modificationsofthenational standardforphotochemical oxidants. Hydrocarbons are

a precursor of photochemical oxidants. Thesole purpose ofprescribing.a hydrocarbonstandard is tocontrol photochem- ical oxidants. Accordingly, the abovedescribed revisions of the national standards for photochemical oxidants necessitated a corresponding revision of the hydrocarbon standards.

National standards fornitrogen dionide have been revised to eliminate the proposed 24-hour average value. No adverse effects on public health or welfare have been associated with short-term exposure to nitrogen dioxide at levels whichhave beenobserved to occurinthe ambient air. Attainment of the annual average will,intheAdministrator'sjudgment, provide an adequate safety margin for protection of public health and will protectagainst known and anticipated adverse effects on public welfare.

Appendices A through F, which describe measurement methods, have been revised to clarify many technical points. As revised, each appendix describes a complete reference method for evaluating the ambient concentration of a pollutant for which national ambient air qualIV standards are being established.

Nine months after the date ofpublication of this notice, the States are required to submit to the Administrator, in accordance with section 110 of the Act, implementation plans for the attainment and maintenance of the national primary and secondary standards specified in this part. Requirements for thepreparation, adoption,and submittal of Implementation plans were published by the Administrator, as proposed rulemaking,intheFEDrnRALREoisrn onApril 7, 1971 (36 F.R. 6680).

In consideration ofthe foregoing and inaccordance withthe statements In the notice ofproposed rule-making, the national primary and secondary ambient air quality standards, Part410, arehereby promulgated effective upon publication.

Dated: April 28, 1971.
WILLiAm D. RUOIMLSUAUS, Administrator. A newPart410isadded to ChapterIV, Title 42, Code of Federal Regulations as follows: Sec. 410,1 Definition,. 410.2 Scope. 410.3 Reference condition5. 410.41 Nationalprimary ambient airquality standards for sulfuroxides (sulfur dioxide). 410.5 Nationalsecondary ambient airqtality standards for sulfur oxide (sulfur dioxide). 410.6 Nationalprimary ambientairquality standards for particulate matter. 410.7 Nationalsecondary ambient airqual- ity standards for partloulate matter. 410.8 National primary and secondary am- bient air quality standards for carbonmonoxide. 410.9 National primary and secondary am- 

## bleat air quality standard for photochemical oxidants. 410.10 National primary and secondary 

## ambient air quality standard for hydrocarbons. 410.11 National primary and secondary am- 

## blent air quality standard for nitrogen diodde %

FEDERAL REGISTER, VOL. 36, NO. 84-FRIDAY, APRIL 30, 1971

## RULES AND REGULATIONS

Appendix A-Peference Method for the Determination of Sulfur Dioxide in the Atmosphere (PararosanllIne Method). Appendix B--eference Method for the Determination ofSuspended Particulatesin theAtmosphere (HighVolnime Method). Appendix C-Reference Metl-nd for the Continuous leasurcmet of Carbon monoxide in theAtmosphere (Nondispersive Infrared Spectrometry). Appendix D-Reference Method for the Measurement of Photochemical Oxidants Corrected for Interferences Due to Nitrogen Oxide and SulfurDioxide. Appendix F-Reference Method for the Determination of Hydrocarbons Corrected forMethane. Appendix F-Reference Method for the Determination of Nitrogen Dioxide (24-HourSampling Method).

AuTron=: The provisions of this Part 410 issued under sec. 4, Public Law 91-004, 

## Stat.1679.

- 

## §410.1 Definitions.

(a) As usedin thispart, alltermsnot defined herein shall have the meaning giventhemby theAct. (b) "Act" means the CleanAirAct, as amended (Public Law-91-604; 84 Stat. 1676).

(c) "Agency"- means the EnvironmentalProtection Agency. (d) "Administrator" means the Administrator of the Environmental ProtectionAgency. (e) "Ambient air" means thatportion oftheatmosphere, external tobuildings, to which the general publichas access. (f) "Reference method" means a method of sampling and analyzing for

an air pollutant, as described in an appendixtothispart. (g) "Equivalent method" means any method of sampling and analyzing for

an air pollutant which can be demonstrated to the Administrator's satisfactiontohave a consistentrelationship to thereference method. 

## §410.2 Scope.



## (a) National primary and secondary ambientairquality standards undersection 109 ofthe Act are set forth in this part. 

## (b) National primary ambient air quality standards define levels of air quality which the Administrator judges



## are necessary, with an adequate margin of safety, to protect the public health. National secondary ambient air quality standards define levels of air quality which the Administrator judges necessary-to protect the public welfare from anyknown oranticipated adverse effects of a pollutant. Such standards are subject to revision, and additional primary andsecondary standardsmaybepromulgatedas theAdministrator deemsneces- sary-to protect the public health and welfare.

(c) The promulgation of national primary andsecondaryambientairqtlality standards shallnot beconsidered in
any mannertoallow significantdeteriorationof existing air qualityin any portioui ofany State. (d) The proposal, promulgation, or revision ofnational primary andsecondary ambient air quality standards shall notprohibit anyState fromestabllshing ambient air quality standards for that State or any portion thereof which are more stringent than the national standards. §410.3 Referenceconditions.

All measurements of air quality are corrected to a reference temperature of 25* C. andto areference pressure of7GO millimeters of mercury (1,013.2 millibars). §410.4 National primary ambient air quality standards for sulfur oxides (sulfurdioxide). 

## The national primary ambient air quality standards for sulfur oxides, measured as sulfur dioxide by thereference method describedin Appendix Ato this part, or by an equivalent method,

are: (a) 80 micrograms per cubic meter (0.03 p.p.m.)-annual arithmetic mean.

(b) 365 micrograms per cubic meter (0.14 

### p.p.m.)-Maximum 24-hour con

## centration not tobe exceededmorethan

onceperyear. §410.5 National secondary ambient air quality standards for sulfur oxides (sulfurdioxide). The national secondary ambient air quality standards for sulfur oxides, measured as sulfur dioxideby thereferencemethod described inAppendix A to this part, or by an equivalent method,

are:

(a) 60 micrograms per cubic meter (0.02 p.p.m.)-annual arithmetic mean.

(b) 260 micrograms per cubic meter (0.1. p.p.m.)-maximum 24-hour concentration nottobeexceeded more than

once per year, as a guide to be ucedin assessingimplementationplanstoachieve the annual standard. (W) 

## 1,300 micrograms perculba meter (0.5 p.pam.)-maximum 3-hour concentration not to be exceeded more than

once peryear. §

### 410.6 National primary ambient air 

## quality standards for particulate matter. 

## The national primary ambient air quality standards forparticulatematter, measured by the reference method described inAppendixB tothispart, orby

an equivalentmethod, are:

(a) 75 micrograms per cubic meterannualgeometrlc mean. (b) 260 microgramsper cubicmetermaximum 24-hour concentration not to beexceededmore thanonceperyear. § 410.7 National secondary ambient air quality standards for particulate matter. 

## The national secondary ambient air quality standards forparticulate matter, measured by the reference method described inAppendixB to thispart, orby

an equivalent method, are:

(a) 60 micrograms per cubic meterannual geometric mean,asa guide to be usedinassessing implementationplansto achieve the 24-hourstandard. (b) 150mlcrorams per cubic metermaximum 24-hour concentration not to be exceededmorethanonceperyea -.

410.3 National primaryandsecondary nmbient airquality standards forcar

### bonmonoxide. 

## The national primary and secondary ambient air qualitystandards forcarbon monoxide, meaured by the reference method dczcrlbed inAppendix Cto this part, orby an equivalentmethod, are: (a) 10 millIgrams per cubic meter (9 p.p.m.)-maximum 8-hour concentrationnot to be exceeded more than once peryear. (b) 40 millI ms percubc meter (35 p.px.)-maximum 1-hour concentration not to be exceeded more than once per year. 

## §410.9 Nationalprimaryandsecondary ambient air quality standards for 

## photochemical oxidants.
The 

## national primary and secondary ambient airquality standard for photochemical oxidants, measured and corrected forinterferences due to nitrogen oxidesandsulfurdioxidebythereference method decribed inAppendix D tothis part, orby an equivalent method, is: 160 micro-rams per cubic meter (0.03 pp.m.)-maximum 1-hour concentraion not tobe exceeded more than once peryear. 

## §410.10 National primary and secondary ambient air quality standardfor 

### hydrocarbons. 

## The hydrocarbons standard is for use
as a guide in deviinfg implementation plansto achieve oxidant standards.

The national primary and secondary ambientair quality standard forhydrocarbons, measwured and corrected for methane by the reference method describedin AppendixEto this part, orby

an equivalentmethod,is: 160mlcrograms percubicmeter (0.24p.pa.)-maximum 3-hour concentration (6to 9a.m.) notto 

## beexceededmorethanonceperyear. §410.11 

## National primary 

## and secondary ambientairqualitystandard for nitrogendioxide.
The national primary and secondary ambientairqualitystandardfornitrogen dioxide, measured by the reference method dezcrlbed in Appendix F to this part,orby an equivJentmethod, is: 100 mlcro7rams per cubic meter (0.05 p.pm.)-annual arithmetic meal.

Ar-.oz'ia (P na.o2.tzzax 2lcr-xcn)

1. Prlfeipac cra AV!fcaTbZftY. 1.1 Sulfur dtddo 13 ab:arbsi from airin a colutfon of pot"-'um tct-cblo oarcurato (TC21). A 

### dlccl .u ftom.rta comylcz.,which rersliz oxidation by tho o..Tyn In the air, is formcs (1. 2). Onc3 formci, this complex is 

## stabloto ctroag oz 2nt3 (e., ozone, ozlds oef nitrcgen). 'lbs comp'cz t; rsactcd rlth
pararc:anlllno and formnldehydo toform Intenaly colorcd parare:nillno methyl ual

## fontc acld (3). 'lbs abz7,rbsnca ofthe zzlutVon ia measured rc,7ctrofhotomscticcily.

1.2 The matheId L7, cppllcb1e tothem=--- urement of sultr diozfdo in amblent air uzlngicmpllnz pcrlc.,up to21houro.

FEDERAL REGISTER, VOL 36, NO. 04-FRIDAY, AFMIL 30, 1971

# 8188

2. Range andSensitivity. 2.1 Concentrations of sulfur dioxide in the range of 25 to 1,050 pg/m. (0.01 to 0.40 p.p.m.) canbemeas- ured under the conditions given. One can
measure concentrations below 25 gg./m.3 by sampling larger volumes of air, but only if the absorption efficiencyoftheparticular system is first determined. Higher concentra- tions can be analyzed by using smaller gas samples,,a larger collection volume, ora suitable aliquot of the collected sample. Beer's Law is followed through the working range from 0.03 to 1.0 absorbance units (0.8 to 27 

### pg.ofsulfite ion in 25 nil. final solution computed as S02).

2.2 The lower limit of detection of sulfur dioxide in 10 ml. TOM is 0.75 pg. (based on twice thestandard deviation) representing a concentration of 25 Ag./m.aO 2 (0.01 p.p.m.) in an air sample of30liters.

3. Interferences. 3.1 The effects 9f the principal known interferences have been minimized or eliminated. Interferences by oxides ofnitrogen are eliminated by sulfamic acid (4, 5), ozone by time-delay (6), and heavy metals by EDTA (ethylenediaminetetroacetic acid, disodium salt) and phosphoric acid (4, 6,). At least 60 pg. Fe (III), 10 pg. Afn(II), and 10 /pg.Cr(III) in 10 ml. absorbing reagent can be tolerated in the procedure. No significant interference was found with 10 pg. CU.(Il) and 22 pg. V(V).

.4. Precision,Accuracy, and Stability. 4.1 Relative standard deviation at the 95 percent confidence level is 4.6 percent for the analytical procedure usingstandard samples. (5)

4.2 After sample collection the solutions

arerelatively stable. At 22 ° C. lossesof sulfur dioxide occur at the rate of 1 percent per day. When samples are stored at 5° C. for 30 days, no detectable losses of sulfur dioxide occur. The presence of EDTA enhances the stability of S02 in solution, and the rate of decay is independent ofthe concentration ofSO2. (7)

5. Apparatus. 5.1 Sampling. 5.1.1 Absorber. Absorbers normally used in air pollution sampling are acceptable for concentrations above 25pg./m.; (0.01 p.p.m.). An all-glass midget impinger, as shown in Figure Al, is recommended for30-minute and 1-hour samples.

For 24-hour sampling, assemble an absorber from the following parts:

Polypropylene 2-port tube closures, special manufacture (available from Bel-Art Products, Pequannock, N.J.).

Glass impingers, 6 mm. tubing, 6 inches long, one end drawn to small diameter such that No. 79 jewelers will pass through, but No. 78 Jewelers will not. (Other end fire polished.)

Polypropylene tubes, 164 by 32 mm. Nalgeneor equal).

5.1.2 Pump. Capable of maintaining an air pressure differential greater than 0.7 at- mosphere atthe desiredflowrate.

5.1.3 Air Flowmeter or Critical Orifice. A calibrated rotameter or critical orifice capable of measuring air flow within ___2 per- cent. For 30-minute sampling, a 22-gauge hypodermic needle 1 inch long may be used

as a critical orifice to give a flow of about 1 liter/minute. For 1-hour sampling, a 23- gauge hypodermic needle five-eighths of an inch long may be used as a critical orifice to give a flow of about 0.5 liter/minute. For 21 .hour sampling, a 27-gauge hypodermic needle three-eighths of an inch longmay be used to give a flow of about 0.2 liter/minute. Use a membrane filter to protect the needle (Figure Ala).

6.2 Analysis. 5.2.1 Spectrophotometer. Suitable for measurement of absorbance at 548 rinm. with

an effective spectral band width of less than 16 nm. Reagent blank problems may occur with spectrophotometers having greater 

## RULES AND REGULATIONS

spectral band width. The wavelength calibration ofthe instrument should be verified. If transmittance is measured, this can be converted to absorbance: A=ogi 0 (1/T) 6. Reagents. 6.1 Sampling. 6.1.1 Distilled water. Must be free from oxidants.

6.1.2 Absorbing Reagent [0.04 M PotassiumTetiachloromercurate (TOM)

## ].Dissolve 10.86 g. mercuric chloride, 0.066 g. EDTA (thylenediaminetetraacetic acid, disodoumn salt), and 6.0 g. potassium chloride in water and bring to mark in a 1,000-mi. volumetric flask. (Caution: highly poisonous. If spilled

on skin, flush off with water immediately). The pH of this reagent should be approximately 4.0, butit has been shown that there is no appreciable difference in collection efficiency overthe range of pH 5 to pH 3.(7) The absorbingreagent is normally stable for 6months. If a precipitate forms, discard the reagent.

5.2 Analysis. 6.2.1 Sulfamic Acid (0.6 percent), Dissolve 0.6 g. sulfamic acid in 100 ml. distilled water.Prepare freshdaily.

6.2.2 Formaldehyde (0.2 percent). Dilute 5 ml. formaldehyde solution (36-38 percent) to 1,000 ml. with distilled water. Prepare daily.

6.2.3 Stock IodineSolution (01 N). Place 12.7 g. iodine in a 250-ml. beaker; add 40 g. potassium iodide and 25 ml. water. Stir until all is dissolved, then dilute to 1,000 mil. with distilled water. 

### 6.2.4 Iodine Solution (0.01 N). Prepare approximately 0,01 I iodine solution by dlluting 50 m. of stok solution to G00 ml. with distilled water.

6.2.5 StarchIndicator Solution.Trlturato 0.4 g. soluble starch and 0.002 g. mercuric iodide (preservative) with a little water, and add the paste slowly to200 ml. boiling water. Continue boiling until the solution Ii clear cool, andtransfer to a glagu-stoppered bottle.

6.2.6 Stock Sodium ThiosullatoSolution (0.1 N). Prepare a stocksolution by dissolving 25 g. sodium thiosulfato (Na 0.5Qv6O) In 1,000 ml. freshly boiled,cooled, distilled water and add 0.1 g. sodium carbonato to the solution.Allow thesolution to stand 1 day beforo standardizing. To standardize, accurately weigh, to the nearest 0.1 mg., 1.5 g. primary standard potassium iodato dried at 180 o 0. and dilute to volume In a 500-ml.volumotrlo flask. To a 500-ml. iodine flash, pipot 50 ml, of Iodate solution.Add 2 g. potassium iodide and 10 mi. of 1 N hydrochloric acid. Stopper theflask. After 5 minutes, titrato with stock thiosulfato solution to a pale yellow. Add 5 ml. starch indicator solution and continue the titration until the blue color disappears, Calculate the normality of the stook solution: W X=-Y2.80 

### M
N=Normality of stock thiosulfato Colution. I=Volume ofthiosulfato required, ml. W=Weight ofpotassium Iodate, grama.

I 103(conversion ofg. to mg.) X0.1 (fraction odato used) 35.67 (equivalent weight ofpotassiumlodate)

6.2.7 Sodium ThiosulfateTitrant(0.01 N). Dilute 100 ml. of the stock thlosulfate solution to 1,000 ml. with freshly boiled distilled water. Ndrmality=Normality of stock solution 

## X0.100.

6.2.8 Standardize Sulfite Solution for Preparationof Working Sulfite-TOM Solution. Dissolve 0.3 g. sodium metabisulfite (NaSO,) or 0.40 g. sodium sulfite (NaSO,) in 500 ml. ofrecentlyboiled, cooled, distilled water. (Sulfite solution is unstable; It is therefore Importantto use water ofthehighest purity to minimize this instability.) This solution contains the equivalent of 320to 400 Ag./ml. of SO. The actual concentration of the solution is determined by adding excess iodine and back-titrating with standard sodium thlosulfate solution. To back-titrate, pipet 50 ml. of the 0.01 N iodine into each of two 500-mi. iodine flasks (A and B). To flask A (blank) add 25 mi. distilled water, and to flask B (sample) pipet 25 mi. sulfite solution. Stopper the flasks and allow to react for 5 minutes. Prepare the working sulfite-TCM SolutioA (6.2.9) at the same time iodine solution is added to the flasks. By means of

a buret containing standardized 0.01 N thiosulfate, titrate each flask in turn to a pale yellow. Then add 5 m. starch solution and continue the titration until the blue color disappears.

6.2.9 WorkingSulflte-TOMSolution.Pipet accurately 2ml. ofthe standard solution into

a 100 ml volumetric flask and bring to mark with 0.04 MfTOM Calculate the concentration of sulfur dioxide in the working solution: 

### (A

- B) (N) (32.000) 25X0.02 25
A=Volume thiosulfate for blank, niL B=Volume thiosulfate for sample,nmL N=Normallty of thiosulfato titrant, 

### 32,000=Milllequivalent wt. ofSO,, pg,. 25=Volume standard sulfito solution, ml. 0.02=Dilution factor. This solution is stable for 30 daya If kept at 50 C. (refrigerator). If not kept at 5° 0,,
prepare daily.

6.2.10 PurifiedPararosantline Stock SofutIon (0.2percentnominal).

6.2.10.1 Dye Specflcations. The pararosanillne dye must meet the following performance specifications: (1) the dye must have a wavelength of maximum absorbanco at 540 nm. when assayed in a bufered volutionof 0.1 At sodium acetate-acetlo acid,, (2) the ibsorbanco of the reagent blank,which Is temperature-sgnsitivo (0.015 abeorbance unit/°C), shouldnot exceed 0.170 ab."orbanco unit at 22" 0. with a 1-oem, optical path length, when the blank Is prepared according to the prescribed analytical procedure andto the specified concentration of the dye: (3) the calibration curve (Section 0,2.1) should have a slope of 0.030±0.002 a1kurb-

anco units/g. SOO at thl path length when the dye is pure and the sulfite solution Is properly standardized.

6.2.10.2 Preparation of Stock Solution. A specially purified (99-100 percent pure) to- lutlon of pararosanilino, which meets the above specifications, Is commercially available In the required 0.20 percent concen- tration (Harleco*). Alternatively, the dye may be purified, a stool solution prepared and then assayed according to the procedureofScaringelli, otal. (4)

6.2.11 Pararosaniline Reagent. To a 250- ml. volumetric flask, add 20 ml. stock pararoaniline solution. Add an additional 0,2 ml. stock solution for each percent thle stocll

*Hartmen-Leddon, 60th and Woodland Avenue,Philadelphia, PA 19143.

FEDERAL REGISTERr VOL 36, NO. 84--FRIDAY, APRIL 30, 1971

## RULES AND REGULATIONS

assays below 100 percent. Then add 25 ml. 3 M phosphoric acid and dilute to volume with distilled water. This reagent Is stable for atleast9 months.

7. Procedure. 7.1 Sampling. Procedures are described for short-term (30 minutes and 1 hour) and forlong-term (24 hours) sampling. One can select different combinations of sampling rate and time to meet special needs. Sample volumesshould be adjusted,so thatlinearity Is maintained between absorbance and con- centration over the dynamic range.

7.1.1 30-Minute and 1-Hour Samplings. Insert a midget impinger into the sampling system, Figure Al. Add 10 ml.TCM solution to the impinger. Collect sample at 1 liter/ minute for 30 minutes, orat 0.5 liter/minute for 1 hour. using either a rotameter, as shown. in Figure Al, or a critical orifice, as shown in Figure Ala, to control flow. Shield the absorbing reagent from direct sunlight during and after sampling by covering the impinger with aluminum foil, to prevent

--deterioration. Determine the volume of air

sampled by multiplying theflowrate bythe time in minutes and record the atmos- pheric pressure and temperature. Remove and stopper the impinger. If the sample must be stored for more than a day before analysis, keep it at 5' C. in-a refrigerator 

### (see42).

7.12 24-Hour Sampling. Place 50 ml. TCM solution in a large absorber and collect the sample at 0.2 liter/minute for 24 hours frommidnight to midnight.Make sure
no entrainment of solution results with the impinger. During collection and storage pro- tect from direct sunlight. Determine the total air volume by multiplying the air flow rate by the time in minutes. The correction of 24-hour measurements for temperature and pressure is extremely difficultand Isnot ordinarily done. However, the accuracy of the measurement will be improved if meaningful corrections can be applied. If storage is necessary, refrigerate at 5' C. (see4.2).

7.2 Analysis. 7.2.1 SamplePreparation. After collection, if a precipitate is observed in the sample,

removeit bycentrifugation.

7.2.1.1 30-Minute and 1-Hour Samples. Transfer the sample quantitatively to a 25- ml. volumetric flask; use about'S ml. distilled water forrinsing. Delay analysesfor20 min

### utesto allowany ozone to decompose.

7.2.1.2 24-HourSample.Dilute the entire sample to 50 ml. with absorbing solution. Pipet 5 ml- of the sample into a 25-ml. volumetric flask forchemical analyses. Bring volume to 10 ml. with absorbing reagent. Delay analyses for 20 minutes to allow any ozone todecompose.

7.2.2 Determination.For each set of determinationsprepare areagent blankbyadding 10 ml. unexposed TCM solution to a 25- ml. volumetric flask. Prepare a control solution by adding 2 ml. of working sulflte-TOM solution and 8 ml. TOM solution to a 25-mi. volumetric flask. To each flask containing either sample, control solution, or reagent blank, add 1 ml. 0.6 percent sulfamlo acid and allow to react 10 minutes to destroy the nitrite from oxides of nitrogen. Accurately pipet in 2 ml. 0.2 percent formaldehyde solution, then 5 ml. par- arosaniline solution. Start a laboratory timerthat hasbeen set for 30 minutes.Bring all flasks to volume with freshly boiled and cooled distilled water and mix thoroughly. After 30 minutes and before 60 minutes, determine the absorbances of the sample (de- note asA), reagent blank (denote as Ao) and the control solution at 548 nm. using 1-cm. opticalpath length cells. Use distilled water, not the reagent blank, as the reference. (NoTE! This is important because ofthe color sensitivity of the reagent blank to tempera- ture changes which can be induced in the cell compartment of a spectrophotometcr.) Do not allow the colored solutlon to stand in the absorbance cells,becauce a film of dye may be deposited. Clean cells with alcohol afteruse. If thetemperature of the detcrmlnations does not differ by more than 2" C. from the calibration temperature (8-). the reagent blank should be within 0.03 abzorbance unit of the y-lntercept of the calibration curve (8.2). If thereagent blank differs bymorethan 0.03 abzorbanco unitfrom that foundIn thecalibration curve,prepare a new
curve.

7.2.3 AbsorbanceRange.If theabsorbanco of the sample solution ranges between 1.0 and 2.0, the sample can be diluted 1:1 with

a portion of the reagent blank and read withina few minutes. Solutions with higher absorbance can be diluted up torisfold with the reagent blank In order to obtain ontcao readings within 10 percent of the true absorbance value.

8.Calibration andEBfIlencies. 8.1 Flowmctcrs and Hypodermic Zicedle. Calibrate flowmeters and hypodermlo nee- dle (8) against a calibrated wct test meter.



### 8.2 Calibration Curres. 8.2.1 Procedure with SuWfIte Solution.Ac. curately pipet' graduated amounts of the 

### 'Worklng'sullte-TCM rolution (0.2.9) (such

s 0, 0.5, 1, 2, 3, and 4 ml.) Into a cries of 25-mi. Tolumetric flasl;. Add sufficent TCOM solution toeach flask to bringthe volume to approximately 10ml.Then addtheremaining reagents as described In 7.2.2. For mwximum precision use a constant-temperaturo bath. The temperature of calibration must be maintained within -tl* 0. and In the range of 20' to 30' 0. The temperature of calibration andthetemperature ofanalysis mustbe within 2 degrees.Plottheab=rbance n ainst the total concentration in pg. SO0 for the corresponding solution. The total rg. So, In solution equals the concentration of the 

### standard (Section 0.2.0) in rg.SOs/mi. time the ml. sulfite solution added (g. S0=-- ,ig./ml. SO2XmL added). A linear relationship should be obtained, and the y-intercept should be within 0.03 abzorbanco unit ofthe

zero standard abzorbance.For maximumprecislon determine the line of best fit using regression analysis by the method of let squares. Determine the slope of the line of best fit, calculate its reciprocal and denote

as Bs. B. Is the calibration factor. (See Section 6.2.10.1 for specifications onthe slope of the calibration curve). This callbration fac- tor can be used for calculating results provided there are no radical changEs in temperature or pH. At least one control sample containing a known concentration of SO for each series of determinations, la recommended to Insure thereliability ofthis factor.

8.2.2 Procedure withz SO Permcation Tubes.

8.2.2.1 General Considerations. Atmospheres containing accurately known amounts of sulfur dioxide at levels of Interest can be prepared using permeation tubes. In the systems for generating theze atmosphere

, the permeation tube emitS SO, gas at a known, low, constantrate,provided thetem- perature of the tubeIs held constant (.!0.1- C.)" and provided the tube has been accu- rately calibrated at the temperature of use. The SO, gas permeating from the tube is carried by a low flow of Inert gas to a mlxIng chamber where It Is accurately diluted 

### with S02

### -frce air to the level oflitercLt and the sample taken. Theze systems are s-hown schematically in F gures A2 and A3 andhave been described in detail by O'Keeffo and Ortman (9), Scarngelll, Frey, and Slt-man (10), and Scaringelli, 

### O'Kceffe, nosenberg, andBell (11).

8.2.2.2 Preparationof Standard Atmospheres. Permeation tubes may be prepared 

# s1s9

or purchae:L Scarlngelll. OHEeeffe, Rosenberg, and Bell (11) give detailed, explicit directions for parmcatlon tube calibration. Tubcs with a certified permeratlon rate are ava-labe fromtheWaflonsl Bureau ofStandard, Tube permeation rates from 0.2 to 0.4 ;g./mlnute Inertgas flows of about 50 mlj minute and dilution airflow ra+te from 1.1 to 15 iters/minutes convenlently give standnrd at==phere- containing desired levels of SO, (23 to 030 p-.!nm:; 0.01 to 0.15 p.p. SO:). Theconcentration ofSO.In anystandard atmozzpherocan ha calculated asfollows: 

### PM103 C=- P,+R, 

### Where:

0 =Concentration of S0, r-./m. at ref-

erenca conditions. P =Tubop emeation rate,p./mlnute. RE=F1ow rate of dilution air, liter/minute atref'erence conditions. Pns=Flw rate ofInert gas, liter/m nute at rcference conditions. 

### 810"' SamplingandPreparation ofCali

## bratftm Curre'.Prepare a ceries (usually six) of standard atmospheres containing E02 levels.from25to p0 g.SO 3Im.2

. Sample esch atmosphere uzingsimilar apparatis and ta- ing exactly the same air volume as will be done in atmcphIerc L-ampling. Determine abszrbanccs az directed In 7.2. Plot the con- 

### centration of2%In rg./m 3 (x-axls) ag.ainst A-A values (-axis) draw,the straightline of bcst fit and determine the slope. Alternatively, rere on nalyzi by the method ofleast squares may be used to calculate the slope. Calculate the reciprocal of the slope and denote asB.

8.3 Sampling Efilclfej. Collection eiclency i, above G3 percent; effiMcency may fall off, hoever, at concentrations below 25 

### ipgjfmA (12,13)

9. Calculations. 9.1 Conrercion of Volume. Convert the volume of air eampled to the volume at ref-
erence conditions of23" C. and 760 -m. Hg. (On 2-hour samples, this may not be possible.)
P233

IGO t+273
V'=Volumo ofair at 250 C. and 760 mm- Hg.liters. V =Volume ofaircampled. liters. P =Barometrio pressure, mm.Hg. t =Tempratur of airsample, 'C. 92 Sulfur Doide Concentration. 02.1 When sulfito solutloz are used to prep=ar calibration curves, compute the con- centratlonofsulfurdloxido In thesample: / (A-Ao) (101) (B.) g. SOdm.2= D
Va
A =Sample abzorbance. A,=lZeagent blank absorbance. 103=Convcsrlon ofliterstocubicmeters. Vn =The sample corrected to 25" C. and 

### 70 rm.Hg.liters. B, =Calbration factor, p./abzorbance unit. D =Dilutlon factor. For 30-minute and 1-hour samples,

D=1. 

### For21-hour cample,.D=10. 92.2 When SOz gas standardatmosphere3

ore uscd toprepare calibration curves, com

## pute the

## culfur dioxide In the rample bythe followingformula: 

## SO.,,pU./m,'=(A-Ao) 1. Bz

A =Sample abcorbance. Aq=Rcaent blank abZorbance. 

### Ba=(SEc 8.2.2.3). 92.3 Coenrsionof rg./m.F to P.p.m.=If desired, the concentration of sulfur dioxide

FEDERAL REGISTER, VOL 36, NO. 84-FRIDAY, APRIL 30, 1971

## RULES AND REGULATIONS

may be calculated as p.p.m. SO, at reference conditionsas follows:
p.p.m. SO=--g. SO/m. X3.82X 10-4 10. Relerences. (1) West, P. W., and Gaeke, G. C., "Fixation ofSulfur Dioxide as Sulfttomercurate III and Subsequent Colorlmetric Determination", Anal. Chem. 28, 1816 (1956). (2) Ephraims, F., 'Inorganic Chemistry," p. 562, Edited by P.C.L. Thorne and E. R. Roberts, 5th Edition, Interscience. (1948). (3) Lyles, G.R.,Dowling,F.B., andBlanchard, V. J., "Quantitative Determination of Formaldehyde in Parts Per Hundred Million Concentration Level", J. Air Poll. Cont.Assoc. 15, 106 (1965). (4) Scaringelli, F.P., Saltzman, B. E., and Frey, S. A., "Spectrophotometric Determination of Atmospheric Sulfur Dioxide",Anal. Chem.39, 1709 (1967). (5) Pate, J. B., Ammons, B. E., Swanson, G. A., Lodge, J.P.,Jr., "Nitrite Interference in Spectrophotometric Determination of Atmospheric Sulfur Dioxide",Anal.Chem.37,942 (1965). (6) Zurlo,N. andGriffini, A. M.,"leasurementofthe SO, ContentofAirin the Presence of Oxides of Nitrogen and Heavy Metals", Med. Lavoro, 53, 330 (1962).

TRAP (7) Scaringelli, F. P., Efers, L., Norris, D., and Hochhelser, S., "Enhanced Stability of Sulfur Dioxide in Solution", Anal. Chem.42, 1818 (1970). (8) Lodge, J. P. Jr., Pate, J. B., Ammons, B. E. and Swanson, G. A., "Uso of Hypodermic Needles as Critical Orifices in Air Sampling," J. Air Poll. Cont.Assoc.16, 197 (1966). (9) O'Keeffe, A. E., and Ortman, 0. C., "Primary Standards for Trace Gas Analysis",Anal.Chem.38, 760 (1966). (10) Scaringelli, F. P., Frey,S. A., and Saltzman, B. E., "Evaluation of Teflon Permeation Tubes forUse with Sulfur Dioxide", Amer. mnd. HygieneAssoc.
J.28,260 (1967). (11) Scaringelli, F. P.,O'Kceffe, A. E., Rosenberg, E., and Bell. J. P., "Preparation of Known Concentrations of Gases and Vapors with Permeation Devices Calibrated Gravimetrically", Anal, Chem.42,871 (1970). (12) Urone, P.,Evans,J. B.,and Noyes, C. M., "Tracer Techniques in Sulfur Dioxide Colorlmetric and Condttctiometric Methods",Anal Chem.37, 1101 .(1965). (13) Bostrom, C. E., "The Absorption of Sulfur Dioxide at Low Concentrations (p.p.m.) Studied by an Isotopic Tracer Method", Intern.J. Air Water 

### Poll.9, 33 (1965).

VIEMBRANE

FILTER 

## orifice flowcontrol.

TO AIR PUMP



## FLOWMETER

FigureAl. Samplingtrain.

FEDERAL REGISTER, VOL. 36, NO. 84-FRIDAY, APRIL 30, 1971 

# 8190

## RULES AND REGULATIONS

IFLOWMCTME 

## P~lo mc

l lRCE'UT,!,", 

## Ela 

# iYIM

,R~ AIC

WATERBSAR

UI L

,parI frIyztl [tl Itl



### I'teloAS. gc I astll r -~ 

### cr =z~jL.
Armm 

### B-MH~Esnucn 11rHof i-n TB=

DfLVMTA=OX OPSuMMMED PAnrTcULArS MTTM AMOSPR (HEGH VOLUIZE



### 1. Piinciple andApplicability. 1.1 Air Is drawn into a covered housing and througha filterby meansofa high-flow- rate blower at a flow rate (1.13 to 1.70 rn./ 

### man.; 40 to 60 

## ftAmin.) that allows sus- pended particles having diameters of less than 100 Am. (Stokes equivalent diameter) to pass to the Mlter surface. (1) Particles -within the Sizerange of 100 to 0.1gm. diame- ter are ordinarily collected onglass fiber fil- ters. The mass concentration of suspended particulates in the ambient air (pg./m. 2) Is computedbymeasuring themass ofcollected particulates and the volume of air sampled. 1.2 Thismethod Isapplicable toicasurcrmentofthe ms concentration ofsu:pended particulates in ambient air. Tho sio of the sample collected is uually adcquate for other analyzes.

2. RangcandScnsi iity 2.1 When the sampler I operated at an average flow rate of 1.70 mnL 2 min. (COft./ min.) for 24 hour, an adcquate sample will be obtained even in an atmosphere having concentratons of suspended partlculatca a low as 1 pZ./nL. If particulate lovelo are 'unusually high, a catisfactory cample may be obtained in 0 to 8 hours or les. For dctcrmination of avera e concentrations of sus- pended parteulatcas in ambient 

### air,a standard eamapling period of 2- hours is recommended. 

# 8191

2.2 Welght are determined to the neare-tm11iram, alrftw ratesare determined to 

### the nearest 0.03 m3ZMlLn. (1.0 ft:.3IinL), times are determined to the nearest 2 

### mninutes and mna-s conacentration are re- pzrtel to the nearest microgram per cub.c 

### meter.

3. Irtcrferencmr 3.1 Particulato matter that Is oily, such 2s photochemical smog or wood smoke may block the filter and cause a rapid drop in

a vilow at a nonunfon rate. Dense tog or highhumidity van cauzo the i1ter tobecome too wet and severely reduce the arfldw 

### through the liter.

3.2 Glas-flber filters are comparativey insensftivo to changes in relative humidity, but cillected part'culates can be hygr- 

### scoplc. (2)

4. Precifon,Accuracy, and Stab rty. 4.1. Based upan colborative testing, the zelative standard deviation (coefcient of variation) for single analyst variation (repeatab=ity of tht methcd) i- 3.0 percent The corep3rdring value formultllahoratry variation (reproduc=ty of the method) Is 

### .3.7percent. (3)

4.2 The accuracy with which-thesampler

measure the true average -concentration depends upon the constancy of the airflow
rate throughthe sampler.Thealrdow rateis affected bythe concentration andthenature of the dust in the atmosphere. Under these condi iomn the error in the measured aver

### age concentration may be in excess of -t50 percentofthetrueaverage concentration. depending an the amount of reduction of air2w rate and on the variatin of theroars concentration of dust with time during the 2A-hour sampling perlod. (4)

S.Apparatu!. 

### 13.1 Sampling. 5.11 Sampler. The sanpler canssts of three units: (1) the faceplate and gasket_ (2) the Mlter adapter aszembly, and (3) the motor unit. 

### Figure BI shows an explded view oftheseparts,their relationshipto each other, and how they are assembled, The rampler mus+be calpable ofpaszing envirnmental air through a 406.5 czm. (63 in.2 ) porIton of a clean 203 by 24 cm- (8- by 10-n.) class-fiber filter at a rate of at least 1.'70m.L/M1n. (C9 ftA'mi). Themotormust be capable of continuous operation far

- ho~ Periods with input voltages ranging frorm 110 to 120 volts, O-Co cycles alternating current and muzt have third-wire safety ground. The housing for the motor unit may be of any convenlent construction so long a. the unit remains airtight and leakfree. The life of the tamplcr motor can be extendLd by lowering the voltage by about 10 percent with a small "bu-_l or boost" 

### trans:former bcatween the saple n oa outlet.

5.1.2 Sampler Shelter. It I- Important that the Lampler bo proparly Installed in a suitable shelter. Tha shelter Is cubjected to extr-me of temImp-aturC, humldty, znd all typc3 of air pDllutants. For these re-s= the matcr"- of the sh.ltr muzt be cl:ron carefully. Propcely painted exterior ply7.'c.d:j

or heavy zauga Cluminum srve wall. The 

### Lampler must bo mountca vcrticualy in the shcltcr CO that the Ca-fiber fiter Is pzrl1el w1th the ground. The shelter must he 

### prov.ided rdth a roofco that,the iter i:;pro- tcctcd from precipltation and debrL. The Internal crran:;mnt and confl.uration of

a sultable rhelterwith a gable roefare zhewn in ITgura B2.The clcarnco area bet-een tha main houzing and the roef at itz clsezst point should be r0.5_i935 em (c2-SO in.). The main hoeuIngshould he rec-tngtrlar,with dimcnsions of about 23 by sC cem (11, by 14 In.).

5.13 rot-eter. ?-,Iard in arbitrary units, frequently 0 to 70. and capable of being calibrated. Other daviczs of at le-t comparablo accuracy may be used.

FEDERAL REGISTER, VOL 36, NO. 84--FRIDAY, APMIL 30, 1971

## 8192

5.1.4 Orifice CalibrationUnit. Consisting of a metal tube 7.6 cm. (3 In.) ID and 15.9

cm. (6% in.) long with a static pressure tap 5.1 cm. (2 In.) from one end. See Figure B3. The tube end nearest the pressure tap Is flanged to about 10.8 cm. (4V in.) OD with

a male thread of the same size as the inlet end of the high-volume air sampler. A single metal plate 9.2 cm. (3% in.) in diameter and 0.24 cm. (%2 in.) thick with a central orifice 2.9 cm. (1% in.) in diameter is held in place
at the air inlet end with a female threaded' ring. The other end of the tube is flanged to hold a loose female threaded coupling,which

screws onto the inlet of the sampler. An 18- hole metalplate,anintegral part oftheunit, Is positioned between the orifice and sampler
to simuiate the resistance of a clean glassfiber filter. An orifice calibration unit is shown In Figure B3.

5.1.5 DifferentialManometer. Capable of measuring to at least 40 cm. (16 in.) of
water.

5.1.6 Positive Displacement Meter. Calibrated in cubic meters or cubic feet, to be used as a primary standard.

5.1.7 Barometer.Capableofmeasuring atmospheric pressure to the nearest mm.

5.2 Analysis. 5.2.1 Filter Conditioning Environment. Balance room or desiccator maintained at 15 ° to 35°C. andless than 50percent relative humidity.

5.22 Analytical Balance. Equipped with

a weighing chamber designed to handle unfolded 20.3 by 25.4 cm. (8- by 10-in.) filters and having a sensitivity of 0.1 mg.

5.2.3 Light Source.Frequently a table of the type used to view X-ray films.

5.2.4 NumberingDevice.Capableofprinting identification numbers on the filters.

6. Reagents. 6.1 Filter Media.Glass-fiber filters having

a collection efficiency of at least 99 percent for particles of0.3 1m. diameter, as measured by theDOP test, are suitable for the quantitative measurement ofconcentrations of suspended particulates, (5) although some other medium, such as paper, may be desirable for

some analyses. If a more detailed analysis Is contemplated, care must be exercised to use filters that contain low background concentrations of the pollutant being investigated. Careful quality control is required to determine background values of these pollutants.

7. Procedure. 7.1 Sampling.
7.1.1 FilterPreparation. Exposeeach filter
to the light source and inspect for pinholes, particles, or otherimperfections. Filters with visible imperfections should not be used. A small brush Is useful for removing particles. Equilibrate thefilters in the filter conditionIng environment for 24 hours. Weigh the filters to the nearest mllligram,, record tare weight and filter Identification number. Do not bend or fold the filter before collection of the sample.

7.1.2 Sample Collection.Open the shelter, loosen the wing nuts, and remove the faceplate from the filter holder. Install a num' bered, preweighed, glass-fiber filter in position (rough side up), replace the faceplate without disturbing the filter, and fasten securely.Undertightening will allow air leakage, overtightening will damage the spongerubber faceplate gasket. A verylight application of talcum powder may be used on the sponge-rubber faceplate gasket to prevent the filter from sticking. During inclement weather the sampler may be removed to a protected area for filter change. Close the roof of the shelter,runthe sampler for about 5 minutes, connect the rotameter to the nipple on the back of the sampler, and read therotameter ball withrotameter in a vertical position. Estimate to the nearest whole number. If the ball is fluctuating rapidly, tip the rotameter and slowly straighten it 

## RULES AND REGULATIONS

until the ball gives a constant reading. DIsconnect the rotameter from the nipple; record the initial rotameter reading and the starting time and date on the filter folder. (The rotameter should never be connected
to the sampler except when the flowis being measured.) Sample for 24 hours from midnight tomidnight and take a final rotameter reading. Record the final rdtameter reading andending time and dateon thefilterfolder. Remove the faceplate as described above and carefully remove the filter from the holder, touching onlythe outer edges.Fold thefilter lengthwise so that only surfaces with collected particulates are In contact, and place in a manila folder. Record on the folder the filternumber,location, andanyother factors, such as meteorological conditions or razing of nearby buildings, that might affect the results. If the sample is defective, void it at this time. In order to obtain a valid sample, the high-volume sampler must be operated with the same rotameter and tubing that

were used during its calibration.

7.2 Analysis. Equilibrate the exposed filters for 24 hours in the filter conditioning environment, then reweigh. After they are weighed, thefilters maybe savedfor detailed chemical 6nalysis.

7.3 Maintenance. 7.3.1 Sampler Motor. Replace brushes before they are worn to the point where
motor damage can occur.

7.3.2 FaceplateGasket.Replace when the margins of samples are no longer sharp. The gasket may be sealed to the faceplate with rubliercementor double-sided adhesive tape.

7.3.3 Rotameter. Clean as required, using alcohol.

.

8. Calibration. 8.1 Purpose.Since only a small portion of the total air sampled passes through the
rotameter during measurement, the rotameter must be calibrated against actual airflow with the orifice calibration unit. Before the orifice calibration unit caix be used to calibrate the rotameter, the orifice calibration unit 4tself must be calibrated against the positive displacement primary standard.

8.1.1 Orifice CalibrationUnit.Attach the orifice calibration unit to the intake end of the positive displacement primary stand,- ard and attach a high-volume motorblower unit to the exhaust end of the primary

.standard. Connect one end of a differential
manometer to the differential pressure tap of the orifice calibration unit and leave the other end open to the atmosphere. Operate the high-volume motor blower unit so that

a series of different, but constant, airflows (usually six) are obtained for definite time periods. Record the reading on the differential manometer at each airflow. The different
constant airflows are obtained by placing a, series of loadplates, one at a time, between the calibration unit and theprimary standard. Placing the orifice before the inlet reduces thepressure atthe inlet ofthe primary standard below atmospheric; therefore, a correction must be.made for the increase in volume caused by this decreased inlet pressure. Attach one end of a second differential
manameter to an inlet pressure tap of the primary standard and leave the other open to the atmosphere. During each of the constant airflow measurements made above,

measure the true inlet pressure of the primary standard with this second differential manometer. Measurp atmospheric pressure and temperature. Correct the measured air volume to true air volume as directed in 9.1.1, then obtain true airflow rate, Q, as directed in 9.1.3. Plotthe differential manometer readings of the orifice unit versus Q.



### 8.1.2 High-Volume Sampler. Assemble a high-volume sampler with a clean filter in place and run for at least 5 minutes. Attach

a rotameter, read the ball, adjust so that the ball reads 65, and seal the adjusting mech

### anlsm so that it cannot be changed easily. Shut off motor,remove the filter,and attach the orifice calibration unit in Its place, Op.
erate the high-volume sampler at a cerlc3 of different,but constant,airflovs (usually olx). Record the reading of the dlfferential manometer on the orifice calibration unit, and record thereadings of the rotamoter at each flow.Measure atmospherlo presuro and tomperature. Convertthe differential manometer reading to m./mln., 0. then plot rotamotpr reading versus Q.

8.1.3 Correction forDifferencesin Presoure
or,Temperature. See Addendum B. 9. Calculations. 9.1 Calibration ofOrifice. 9,1.1 TrueAir Volume. Caloulate the air volume measured by the positive dlsplacementprimary standard. 

### (PA-P M

### ) VX=-(V,) PA
V,=True air volume at ltmozpherlo pres- "sure,i 3 P,=Baromotric pressure,mm.Hg, Pm=Pressuro drop at inlot of primary standard, mm.Hg. Vu=Volume measured by primary t.And

### ord,m.3

9.1.2 ConversionFactors. Inches Hg.X25.4mm. Hg. 

### IncheswaterX73.48>,10-3=Inehes Hg. Cubicfeet aIrx<0.028t=oublo moters air, 9.1.3 TrueAirflotoRate,
Vs



### T Q=Flowrate,m.5/mlmn T=Tlme offlow, m11

9.2 Sample Volume, 9.2.1 Volume Conversion.Convert the Initial and final rotameter readinga to true airflow rate, Q, using calibration curve of 8.12.

9.2.2 Calculatevolumeof air sampled QlQ 

### V=-XT 2
V=Airvolume sampled, m.8 Q, =Initial airflowrato,m.9/mln. Qt



### =inal alrflow rate, mW/min. T=Sampling time,min.
9.3 Calculatemass concentrationofsuspendedparticulates (Wf-W) 

### X.IOi S.P.= V
S.p.=Mas concentration of ousponded 

### particulates, pg/m. 

### Wi=Initial weightoffilter,g. Wt=Final weight offilter,g.

V=AIr volumesampled, m.' 

### 104=Conversion ofg. topg. 10. References. 

### (1) Robson, C. D., and Foster, 

## , V, "Evaluation of Air Parteolato Sampling Equipment", Am. lnd. llyor. Assoc. J. 24, 404 (1902). (2) Tlerney, 0. P., and Conner, W, D., "Hygroscopic Effects onWeight Determinations of Particulates Collected on Glass-Fiber Filters", Am Ind. fluy. Assoc. J. 28, 363 (1967). (3) Unpublished data based on a collaborative test Involving 12 partlolpants, conducted under the direction of tile Methods Standardization Servicei klootion of theNational AirPollution Control Administration, October, 1970. (4) Harrison, W. X., Nader, J. S,, and Fug

### man, F. S., "Constant lovi 

## Regulators for High-Volume Air Sampler", Am. 

### -nd.Hyg. Assoo. J. 21, 114-120 (1960).

FEDERAL REGISTER, VOL. 36, NO. 84-FRIDAY, APRIL 30, 1971

## RULES AND REGULATIONS

(5) Pate, J.B., and Tabor, E. C.. "Analytical Aspects of the Use of Glass-Fiber Fil

### ters forthe Collection and Analysis of Atmospheric Particulate Matter", Am. lZd.Hyg. ASsoc. J. 23, 144-150 (1962). .ADDENDA
.A. A ternative Equipment. 

### Amodification ofthehigh-volume sampler incorporating a method for recording the actual airflow over the entire sampling period has been described, and is acceptable for measuring the concentration of suspended particulates (Henderson. J.S.,Eighth Conference on Methods in Air Pollution and Industrial Hygiene Studies, 1967. Oakland, 

### Calif.). This modification consists of an ex- lhaust orifice meter assembly connected through a transducer to a system for con- tinuously recording airflow on a circular chart. The volume of air sampled Is calculatedbythefollowingequation: V=QXT.
Q=Average samplingrate,m.3/mln. 

### T=Samplingtime,minutes. The average sampling rate, Q, is determined from the recorder chart by estimation if the flowrate does not vary more than 0.11 rn3/ 2nin. (4 It./mn.) during -thesampling period. If the flow rate does vary more than 0.11 mLP (4 ft.Plmin.) during the sampling period, read the flow rate from the chart at2-hourintervals andtakethe average.



### B. Pressureand TemperatureCorrections. rILTER 

### FOSIT103 If the prcaure or temprature during high-volume sampler calibration 13cub;tan- 

### tiallydifferent fromthe prc ura ortcmcra

- ture during orlilce callbration, a carrc-i-tln of the flow rate, Q, may ba rcqulrc:L If the prZ~urco differ by no more than 1G pcrccnt and thetemperature differ byno more thnn 100 percent (OC), the errar in the un- corrected flow rate =ill be no oro thzn 15 

### percent. If ncwary. obtain the caerrcted flow rate as directed below. ThIs correction applIes only to orifice moters havlng a con- stant orifico caciflent. The cecilent for the calibrating orifice dc:rlbed In 5.1.4 ha been chown experLmentally to ba constant
over the normal opcratmng range of thehlghvolume ca=mpler (0.6 to 2 mNmln.; 20 to 73 ft.P/min.). Calculate corrected flow rate:

QO=Correctedflowrate m./min. OQ=Flow rate during high-volume campler calibration (Eecton 8.1.2), m. 3 /mln. T1=Abcoluto temperature during orifica unit calibration (SEctlon 8.1.1), "1Z

or

. P±=Baromctrlc pre--ure during oriice unit 

### calbration (Section 8.1.1), mm. Hg. T2=Abzoluto temperature during highvolume rampler calibration (Section 8.1"). 1E or "R. P:=Barometrla pre--ure during high-vol-

umo sampler calibration (SEction 8.12). mm. Hg.



### FJ~so SI. E~;~:l~:~z ciIy~ 1

### .rli-'~'~r!z~ rc:-;~f zls.

FEDERAL REGISTER, VOL 36, NO. 84-FRIDAY, APRIL 30, 1971 

## 8193

NO.81---t, 1I-2

## RULES AND REGULATIONS

Figure 12. Assembled samplerand shelter.

ORIFICE RESISTANCE PLATES



## Figure B3, Orificecalibrationunit.

APPENDIX C-REFRENCE METHOD FOR THE

CONTINUOUS MEASUREENT OF CARBON MONOXIDE IN THE ATIOSPHERE (NowDISPERsIVE INFRARED SPEcTROMETRY)

1. Principle andApplicability. 1.1 This method: is based on the absorption of infrared radiation by carbon monoxide. Energy from a source emitting radiation in the Infrared region is split into parallel beams and directed through ref-i

erence and sample cells. Both beams pass into matched cells, each containing a selective detector and CO. The CO in the cells absorb infrared radiation only at its characteristic frequencies andthe detector is sensitive to these frequencies. With anonabsorbing gas in the reference cell, and with no CO in the sample cell, the signals from both detectors are balanced electronically. Any CO introduced into the sample cell will absorb radiation, which reduces the temperature and pressure in the detector cell and displaces a diaphram. This, displacement is detected electronically and amplified to provide an output signal. 

### 1.2 This method is applicable to the dotermination of carbon monoxide in ambient air, and to the analysis of gazes under preszure.

2. RangeandSensittity. 2.1 Instruments are available that moa-
ure in the range of 0 to 53 mg./m.8 (0-50 p.p.m.), which Is the range mozt commonly used for urban atmospheric c.ampling. tfost instrumentsmeasure inadditionalranges,

2.2 Sensitivity Is 1 percent of full-scale responseper0.6 mg.CO/m.3 (0.6 p.p.m.).

3. Interferences. 3.1 Interferences vary between Individual instruments. The efrect of carbon dtoxide interference at normal concentratlonu Is minimal. The primary Interference ISwater vapor, and with no correction may give an interference equivalent to as high as 12 nag. CO/n' 3 

### Water vapor interference can be minimized by (a) passIng the air sample through silica gel or similar drying agents, (b) maintaining constant humidity in the sample and calibration gases by refrigeration, (c) saturating the air r-umplo and callration gases to maintain constant humidity or (d) using narrowband optical fltera in combination with come of these measures.

3.2 Hydrocarbons at ambient levels do not ordinarily interfere.

4.Precision,Accuracy, and Stability. 4.1 Precision determined,with calibration gases Is t0.5 percent full scale in the 0-8 mg./m.3 

### range.

4.2 Accuracy deponds on Instrument linearity and the absolute concentratlons of the calibration gases. An accuraey of ± 1 percent of full scale in the 0-53 mg./nt range canbe obtAned.

4.3 Varlationz in ambient room tcmpeorture can cause changen equivalent to a much as 0.5 mg. CO/m.0 per °0. This offee
can be minimized by operating the analyzer in a temperature-controled room. Prettro changes between span chcoks will causO changes in instrument response, Zero drift is usually less than ±1 percent offull scale per 24 hours, if cell temperature and prej-

surearemaintained constant.

5. Apparatus. 5.1 CarbonMonoxide Analyzer. Connercially available instruments should be installed on location and demonstrated, pref- erably by the manufacturer, to meeot or exceed manufacturers specifications and those described Inthis method.

5.2 Sample IntroductionSystem. Pump, flow control valve,and flowmeter.

5.3 Filtef(In-line).A filterwth aporosity of 2 to 10 microns should be Used to keep large particles from the sample coll.



## 5.4 MoistureControl, Refrigeration units

are available with some commercial Instruments for maintaining constant humidity. Drying tubes (vith sufficient capacity tooperate for 72 hours) containing Indicating silica gel can be used. Other techniquea that prevent the Interference of moisture are satisfactory.

6. Reagents. 6.1 Zero Gas.Nitrozen or helium cont-aininglessthan0.1 mag. CO/m. 3 

### 6.2 CalibrationGages. Calibration twea corresponding to 10, 20, 40, and 80 percent of full scale axe used. Gase must be provided with certification or guarinecd analysls ofcarbonmonoxid6content,

6.3 Span Gas. The calibration ga corre- sponding to 80 percent offull scale Is used to span the instrument.

7. Procedure. 7.1 Calibrate the instrument as descrlbed in 8.1. All gases (sample, zero, calibration, and span) must be introduced into the en- tire analyzer system. Plguro 01 showo a typical flow diagram. ror specific operating Instructions, refer to the manufacturer'a manual.

-

FEDERAL REGISTER, VOL. 36, NO. 84-FRIDAY, APRIL 30, 1971

## RULES AND REGULATIONS

8. Caiibratiofl. 8.1 Calibration Curve. Determine the linearity of the detector response at the operating flow rate and temperature. Prepare a calibration curve and check the curve -furnished with the instrument. Introducezero gas and set the zero control to indicate

a recorder reading of zero. Introduce span gas and adjust the span control to indicate the proper value on the recorder scale (e.g.-

on 0-58 mg./m-3 scale, set the 46 mg./m. standard at 80 percent of the recorder cha3t). Recheck zero and span until adjustments are no longer necessary. Introduce intermediate calibration gases and plot the -values obtained. If a smooth curve is not obtained, calibration gases may need replacement.

- 9. Calculations. 9.1 Determine the concentrations directly from the calibration curve. No calculations

are necessary.

9.2 Carbon monoxide concentrations in mg./m.S are converted to p.pam. as follows:

p.p.m. CO=mg. CO/m. X0.873

10. Bibliography. The Intech NDIR-CO Analyzer by Prank McElroy. Presented at the llth Methods Conference in Air Pollution, University of California, Berkeley, Calif., April 1, 1970.

Jacobs, B. B. et al., J.A.P.C.A. 9, No. 2, 110114, August 1959.

M A LIRA Infrared Gas and Liquid Analyzer Instruction Book, Mine Safety Appliances Co., Pittsburgh,Pa.

Beckman Instruction 1635B, Models 215A, 315A and 415A Infrared Analyzers, Beckman Instrument Company, Fullerton, Calif.

Continuous COMonitoring System, Model A-5611, Intertech Corp., Princeton, N.J.

Bendix-UNOR Infrared Gas Analyzer,. Ronceverte, W. Va.
A'nDENDA

A. Suggested. Performance Specifications forNDIR Carbon3onoxideAnalyzers:
Range (minimut) ---- 0-58mg./m.' 

### (0-50 p.pm). Output (minimum)--- 0-10, 100, 1,000,- 5,000 my. full scale. Minimum detectable sen- 0.6 mg./m 3 (0.5

sitivity.

- p-pm.).

Lag time (miximum)-- 15seconds. Time to 90 percent re- 30seconds.

sponse (maximum). Rise time, 90 percent 15 seconds.

(maximum). Fall time, 90 percent 15 seconds.

(nimumL.

Zero drift (maximum)--- 3 percent/week. not to exceed 1 percent/24 hours. Span drift (maximum)-- .3 percent/week, not to exceed 

### 1 percent/24 hours. Precision (minimum)--- __0.5 percent. 

### Operational period -(min- 3days.

imum). Noise (maximum)------- -±0.5percent. Interference equivalent. 1 percent of full

(maximum). scale.

- Operating temperature 5-40' C.

range (minimum). Operatinghumidity range 10-100 percent.



### (minimum). Linearity (maximum de- 1 percent of full

viation). scale.

B. Suggested Definitions of Performance 

### Specifications: Range-The minimum and maximum measurement limits. Output-Electrical signal which Is proportional to the measurement: intended for connection to readout or datA processing devices. Usually expressed as millivolts or milliamps full scale at a given impedance. Pull Scale-The maximum measuring limit

for a givenrange. Minimum Detectable Sensitivity-The smallest amount of input concentration that

can be detected as the concentration ap

### proaches zero. Accur acy-The degree ofagreement between

a measured value and the true value; usually expressed as

_percent of full ccale Lag Time--The time interval from a step

change In Input concentration at the Instrument inlet to the first corresponding change in the instrument output. Time to 90 percent Re:ponse-The time Interval from a step change in the input concentration at the instrument Inlet to

a reading of 90 percent of the ultimate recorded concentration. Rise Time (90 percent)-The nterval between initial response time and time to 90 percent response after a step ncreo in the Inlet concentration. Fall Time (90 percent)-Tho interval between initial response time and time to 90 percent response after a step decrease in the inletconcentmton. Zero Drift-The change In instrument output over a stated time period, usually 24 hours, of unadjusted continuous operation, when the Input concentration is

zero; usually eapreased as percent full scale.

SA%'PLEIHTRODUCT10WI

APPm.rmxx D-REF EE N MMHOin ron T1n 

### MU&sunxRnEr OFPHOrOCE=mL OxM.%rrrm CoasR~crm ) 

### oa 

## INr=.ainrcrs DvE zo Nrr rouo OxmD Aimo SuLrru Dioxmn
1. Principleand Applicability. 1.1 Ambient air and ethylene ae delivered simultaneously to a mixing zonO where the ozone in the air reacts with the ethylene to emit light which ts detected by

a photomultipiler tube. Theresulting photo

## current is amplifled and Is eitherread directly or displayed ona recorder.

1.2 The method is applicable to the con

### tinuous measurement of ozone in ambient air.

2. RangeandSensitfirty, 2.1 The range is 9.8 pg. O.m. 5 to greater than 1960 Ng. Oinm.8 (0.005 p.pxm 0 to grpater than 1p.pm. 0,). 

### Span,DrIft-The ch ge In instrumint output over a sted time period, usually 24 hours, of unadju:-ted continuous operation, when the Input concentration is a stated upscale value; usually expresed as percent full scale. Precison-The degree ofagreement between

repeated me-surements of the ""ie concentration. expresed as theaverage deviation of the ringle results from the mean. Operational Period-Tho pcriod of timeo-er

which the instrument can be expected to operate unattended within specifications. NoeL-Spontaneouo deviations from a mean

output not caused by input concentration changes. Xnterference-An undesired pocitive ornegative output cauced by a Substance other than the one being me-mured. Interference Equivalent-The portion of

indicated Input concent-atfon due to the presence ofan Interferent. Operating Temperature Range-The range

of ambient temperatures o-er which the instrument will meet all performance pecwficatlons. Operating Humidity lange--The range of

ambient relative humidity over which the Instrument will meet all performance specfilcations. Linearity-The m-aimum devlation between

an actual ismtrument reading and the reading predicted by a straightline drawn between upper and lower calibration points.

2.2 The s'-,itivity 139.8 pg. O,0 s (0.005 p.pM. 03).

3. lntcrfcrcC3ce. 3.1 Other oxid ng and reducing species normally found in ambient air donotinterfere.

4. Prccsi~on andAccuracy. 4.1 The average deviation from the mean ofrepeated singlemeasurements does notexceed 5percent of the mean ofthe m-easure- ments.

4.2 The mothod is accurate within -7 percent.

5. Appzratu3. 

## 5.1 D tectorCcll.FigureDI 

## is a draz

## inofa typical detector cell showing dow pa. th of gaes., the miin zone, andpLacement of the photomultiplier tube. Other flow p3fhz in which the air and ethylene streamn meet

FEDERAL REGISTER, VOL 36, NO. 84-FRIDAY, APRIL 30, 1971 

# 8195-

Ff:=Cf.

## 8196

at a point near the photomultiplier tube are also allowable.

5.2 Air Flowmeter. A device capable of controlling air flows between 0-1.5 I/mi.

5.3 Ethylene Flowmeter.A device capable of controlling ethylene flows between 0-50 ml./min.At anyflow in thisrange, the device' should be capable of maintaining constant flow rate within ±3 ml./min.

5.4 Air Inlet Filter. A Teflon filter capable ofremoving all particlesgreater than 5 microns In diameter.

5.5 PhotomultiplierTube. A high gain low dark current (not more than. lxl0-D ampere) photomultlpller tube having its maximum gain at about 430 nm. The following tubes are satisfactory: RCA 4507, RCA 8575, EAI 9750, EAU 9524, and EMI 9536.

5.6 High Voltage Power Supply. Capable of delivering up to 2,000 volts.

5.7 Direct CurrentAmplifier. Capable of fullscale amplification of currents from 10-"0 to 10-7 ampere; an electrometer Is commonly used.

5.8 Recorder. Capable offull scale display ofvoltages from the DC amplifier.These voltages commonly areIn the 1 millivolt to 1-volt range.

5.9 Ozone Source and Dilution System. The ozone source consists of a quartz tube into which ozone-free air s introduced and then irradiated with a very stable low pres- suremercury lamp.Thelevel ofirradiation is controlled byan adjustable aluminum sleeve 'which fits around the lamp. Ozone concen- trations are varied by adjustment of this sleeve. At a fixed levelof irradiation, ozone is produced at a constant rate. By carefully controlling the flowof airthroughthe quartz tube, atmospheres are generated which con- tain constant concentrations of ozone. The levels of ozone in the test atmospheres are determined by the neutral buffered potas- sium Iodide method (see section 8). This

ozone source and dilution system is shown schematically In Figures D2 and D3, andhas been described by Hodgeson, Stevens, and Martin.

5.10 Apparatusfor Calibration 5.10.1 Absorber. All-glass impingers as shown In Figure D4 are recommended. The Impingers may be purchased from most ma- Jor glassware suppliers. Two absorbers in series are needed to insure complete collectionofthe sample.

5.10.2 Air Pump. Capable of drawing 1 liter/minute through the absorbers. The pump shouldbe equipped with a needle valve

on the inlet side to regulate aow.

5.10.3 Thermometer. With an accuracy of ±20 C.

5.10.4 Barometer.Accurate to the nearest
mm. Hg.

5.10.5 Flowmeter.Calibrated metering device for measuring flow up to 1 liter/minute within ±2 percent. (For measuring flow through Impingers.)

5.10.6 Flowmeter.For measuring airflow pastthe lamp; must be capable ofmeasuring flows from 2 to 15 liters/minute within ±5 percent.

5.10.7 Trap.Containing glasswool to protect needle valve.

5.10.8 Volumetric Flasks. 25, 100, 500, 1,000 ml.

5.10.9 Buret.50 ml. 5.10.10 Pipets.0.5, 1, 2, 3, 4, 10, 25, and 50 ml. volumetric.

5.10.11 Erlenmeyer Flasks. 300 ml. 5.10.12 Spectrophotometer. Capable of measuring absorbance at 352 nm. Matched 1-cm. cells should beused.

6. Reagents. 6.1 Ethylene. C.P. grade (minimum). 6.2 CylinderAir.Dry grade. 6.3 Activated CharcoalTrap.For filtering cylinder air. 

## RULES AND REGULATIONS

6.4 PurifiedWater. Used for all reagents. Todistilled or delonized water in an all-glass distillation apparatus, add a crystal ofpotassium permanganate and a crystal of barium hydroxide, and redistill.

6.5 Absorbing Reagent. Dissolve 13.6 g. potassium dihydrogen phosphate (KBIPO4), 14.2 g. anhydrous disodium hydrogen phosphate (Na 2HPO 4) or 35.8 g. dodecahydrate salt (NaHPO 412HEO), and 10.0 g. potassium iodide (KI) in purified water and dilute to 

### 1,000 ml. The pH should be 6.8+0.2. The .solution Is stable f9r several weeks, if stored in a glass-stoppered amber bottle in a cool, dark place.

-

6.6 Standard Arsenious Oxide Solution (0.05 N). Use primary standard grade arse- nious oxide (AspO). Dry 1 hour at 105" C. immediately before using. Accurately Weigh 2.4 g. arsenious oxide from a small glassstoppered weighing bottle. Dissolve in 25 ml. 1 N sodium hydroxide in a flask or beaker on a steam bath. Add 25 ml. 1 N sulfuric acid. Cool, transfer quantitatively to a 1,000-ml. volumetric flask, anddilute to volume. NoTE: Solution must be neutral to litmus, not alkaline.

wt As.O, (g.) Normality AsOa=- 49.46
6.7 Starch Indicator Solution (0.2 percent). Triturate 0.4 g. soluble starch and approximately 2mg. mercuric Iodide (preservative) witha littlewater.Add the paste slowly to 200 ml. ofboiling water. Continue boiling until the solution is clear, allow to cool, and transfer to a glass-stoppered bottle.

6.8 StandardIodineSolution (0.05 N). 6.8.1 Preparation. Dissolve 5.0 g. potassiumiodide (KI) and3.2 g.resublimed iodine (12) in 10 ml.purified water. When the f~dine dissolves, transfer the solution to a 500-mi. glass-stoppered volumetric flask. Dilute to mark with purified water and mix thoroughly. Keep solution in a dark brown glassstoppered bottle away from light, and re- standardize as necessary.

6.8.2 Standardization. Pipet accurately 20 ml. standard arsenious oxide solution into a 300-ml. Erlenmeyer flask. Acidify slightly with 1:10 sulfuric acid, neutralize with solid sodium bicarbonate, and add about 2 g. ex- cess. Titrate with the standard iodine solution using 5 ml. starch solution as indicator. Saturate the solution with carbon dioxide

near the end point by adding 1 ml. of 1:10 sulfuric acid. Continue the titration to the first-appearance of a blue color which persists for 30 seconds.
ml. As2OXNormallty AsO 3 

### Normality I-= ml. 12
6.9 DilutedStandardIodine.Immediately before use, pipet 1 ml. standard iodine solution into a 100-ml. volumetric flask and dilute tovolume with absorbing reagent.

7. Procedure. 7.1 Instruments can be constructed from the components given here or may be pur- 'chased.If commercial instruments are used, follow the specific instructions given in the manufacturer's manual. Calibrate the nstrument as directed in section 8. Introduce samples into the system under the same conditions ofpressure and flow rate as are used in calibration. By proper adjustments of zero and span controls, direct reading of ozone concentration is possible.

8. Calibration. 8.1 HI Calibration Curve.Prepare a curve of absorbance of various Iodine solutions against calculated ozone equivalents as follows: 8.1.1 Into a series of 25 ml. volumetrio flasks, pipet 0.5, 1, 2, 3, and 4 ml. of diluted standard Iodine solution (6.0). Diluto each to the mark with absorbing reagent. Mix thoroughly, and Immediately read the absorbance of each at 352 nrn. against 

### imesipored absorbing reagent as the reference.

8.1.2 Calculate the concentration of the solutions astotal pg.Oaasfollows: 

### Total jzg.0,= (N) (00) (VI) N=Normallty I4 (sea 68.2), meq./ml. V,=Volumo of diluted Mandard Ij added, ml. (0.5, 1,2, 3, 4). Plot absorbanco versus total pg.,
.

8.2 Instrument Calibration, 8.2.1 Generationof TestAtmos'phres.Assemblo the apparatus as shown In Figuro D3. The ozone concentration produced by the generator can be varied by changing the po- sition of the adjustable sleeve. For calibration of ambient air analyzers, the ozone source should be capable ofproduoing ozono concentrations In the range 100 to 1,000 1g./m.' (0.05 to 0.6 p.p.m.) at a flow rate of at least 5 liters per minute. At all times the airflow through the generator mu5t begreat-
er ,than the total flow required by the sam- pling systems.

8.2.2 Sampling andAnalyses of Test Atmospheres.Asssmblo the KI sampling train
as shown In Flguro D4. Use ground-glas connections upstream from the Impingtr. Butt-to-butt connections withTygon tubing may be used. The manifold distributing thlo test atmospheres must be sampled simultaneously by the KI sampling train and the instrument to be calibrated. Cheek assrem- bled systems for leaks. Record the instru- ment response In nanoamperes at each concentration (usually six). E tablish thoe concentrations by analysis, using the neu- tral buffered potassium Iodide method as follows:

82.2.1 Blan:.With ozone lamp off, flu h the system for several minutes to remove residual ozone. Pipot 10 ml. absorbing re- agent into each absorber. Draw air from the ozone-generating system through the sam- pling train at 0.2 to 1 liter/minute for 10 minutes. Immediately transfer the exposed solution to a clean 1-cm, cell. Determine the absorbance at 352 nm. against unexposed absorbing reagent as the reference. If the system blank gives an absorbance, continue flushing the ozone generation system until

no absorbance is obtained.

8.2.2.2 Test Atmospheres. With the ozone lamp operating, equilibrato the system for about 10 minutes. Pipet 10 ml. of abs-orblng reagent into each absorber and collect camples for 10 minutes In the concentration range desired for calibration. Immediately transfer the solutions from the two absorbers to clean 1-cm. cells. Determine the absorbance of each at 352 nm. against unexposed absorbing reagent asthe reference. Add the absorbances of the two solutions to obtain total abzorbanceo. Read total ,g.O.1 from the calibration curve (see 8.1). Calculate to- tal volume of air sampled correeted to ref-

erence conditions of 25* C. and 760 mm. 11g.

as follows: 1 298 

### Vn"VX- *'

- X'10-a 760 t+273 Va =Volume of air at reference condltions,m.3 V =Volume of air at sampling condltons,liters. P =Barometrlc pressure at sampling conditions, mm. Hg.
t =Temperature atsampllng conditions, Co. 

### 10-3=Conversilon ofliterstoin.3

FEDERAL REGISTER, VOL 36, NO. 84-FRIDAY, APRIL 30, 1971

## RULES AND REGULATIONS

Calculate ozone concentration in popxm. as 9.3 Converlon botween pp. and p, follows: m.t valuc3 forczono can be made o.a follwa: 

### 1g.o0 p.p.m. 03=- X5.10X 10- VU 82.3 Instrument Calibration Curve. Instrument response fromthe photomultlplier tube Is ordinarily in current orvoltage. Plot the current, or voltage if appropriate, (y-axis) for the test atmospheres against
ozone concentration as determined by the neutral buffered potassium Iodide methcd, inp.pJm. (x-axis).

9. Calculations. 9.1 If a recorder is used which has been properly zeroed and spanned, ozone concen- trationscanbereaddirectly.

9.2 Ifthe DC amplifier is read directly, the reading must be converted to ozone concentrations usingthe instrument calibrationcurve (8.2.3).



## SAMPLEAIR IN



# EXHAUST p.p~M. 0j=

- V.;5.10"*'10-,



### 10. Bibliograp7y. Hodgczon, J. A., Martin. B. El.. and Baumgardner. 3R E., "Comparicon of Chemliumlnezcent Methods for Mea.urement of Atmozpherlo Ozone". PboZr= In Analyttcal Chemltry. Vol. V. Plenum Prcza, 1971.

Hodgc:on, J. A., Stevenw, R.K, and Martin, B. E., "A Stablo Ozone Source Applicable as
a Secondary Standard for Calibration of Atmospl eric Monitora", AnnlyaL Intrumtentation Sympocfum. Instrument Society of America, Houoton, T

..,April 1971.

Nederbragt, G. W, Van der Horat, A., and Van Duljn.J.,Mature20G, 87 (190).

Warren, G. J., and Babcock, G., Rev. Scf. 

### Intr. 4Z, 28D (1070).



## , ETHYLENE IN

rm



## PYRF. CONSTRU"TION

I- 4A0.0.

FLAT

Figure D1. Detectorcell.

FEDERAL REGISTER, VOL 36, NO. 84-FRIDAY, APRIL 30, 1971 

# 8197

m a I-

## RULES AND REGULATIONS

APPENDIX E-REFERENCE MrmOD POr DETim- =Iu;ATION Or HYDROCARBOiS CORECTED 3OR METHAN4E
1. PrincipleandApplicability. 1.1 Measured volumes of air are delivered semicontinuously (4 to 12 times per hour) to a hydrogen flame Ionization detector to
measure its total hydrocarbon (THC) con- tent. An aliquot of the same air sample is Introduced into a stripper column which re- moves water, carbon dioxide, hydrocarbons other than methane, and carbon monoxide. Methane and carbon monoxide are passed quantitatively to a gas chromatographic col-
umn where they are separated. The methane Is eluted first, and is passed unchanged through a catalytic reduction tube into the flameIonization detector.Thecarbonmonox- Ide Is eluted Into the catalytic reduction tube where It is reduced to methane before passing through the flame ionization de- tector. Between analyses the stripper column is backfluihed to .prepare it for subsequent analysis. Hydrocarbon concentrations cor- rected for methane are determined by subtracting the methane value from the total hydrocarbon value.

Two modes of operation are possible: (1) A complete chromatographic analysis showing the continuous output from the detector for each sample injection; (2) The system is programed for automatic zero and span to display selected band wldths of the chromatogram. The peakheight Is thenusea
as the measure of the concentration. The former operation is referred to as the chromatographic or spectro mode and the latter

as the barographic or "normal" mode depending onthe makeof analyzer.

1.2 The method is applicableto the semlcontinuous measurement of hydrocarbons corrected for methane in ambient air. The carbon monoxide measurement, which is simultaneously obtained In this method, is not required In making measurements of hydrocarbons corrected for methane and will notbedealt with here.

2. Range andSensitivity. 2.1 Instruments are available with vari-

ous range combinations. For atmospheric analysis the THO range is 0-13.1 mg./m s (0-20 p.pan.) carbon (asC.H,) andthe meth-

ane range Is 0-6.55 mg/m.3 (0-10 p.p~m.). For special applications, lower ranges are available and in these applications the range for 

### THO is 0-1.31 mg./m.3 

### (0-2 p.pm.) carbon (as CH,) and for methanethe rangeis 0-1.31 mg./m. 3 (0-2 p.pmn.). 2.2 For the higher, atmospheric analysis ranges the sensitivity for THO is 0.065 mg./m 3 (0.1 p.pmn.) carbon (as ,H 4) and for methane the sensitivity is 0.033 mg./m. 3 (0.05 p.p.m.). For the lower, special analysis ranges the sensitivity is 0.016-mg./m.5 (0.025 p.pa.) for each gas.

3. Interferences. 3.1 No interference in the methanemeas- urement has been observed. The THe meas- urement typically includes all or a portion of what is generally classified as the air peak interference. This effect is minimized by proper plumbing arrangements or is ne- gated electronically.

4. Precision, Accuracy, and Stability. 4.1 Precision determined with calibration gases is +0.5 percent of full scale in the higher, atmospheric analysis ranges.

4.2 Accuracy is dependent on instrument linearity and absolute concentration of the calibration gases. An accuracy of1 percent of full scale in the higher, atmospheric analysis ranges and 2 percent of full scale in the lower, special analysis ranges can be obtained.

4.3 Variations in ambient room tempera- turecan cause changes in performance chartacterstles. This is due to shifts in oven temperature, flow rates, and pressure with ambient temperature change. The instru- ment should meet performance specifications with room temperature changes of ±.3* C. Baseline drift Is automatically corrected in thebarographic mode.

5. Apparatus. 5.1 Commercially Available THC, CH4, andCO Analyzer.Instruments should be Installed on location and demonstrated, preferably by thd manufacturer, or his representative,to meet or exceedmanufacturer's specifications and those described in this method.

5.2 Sample Introduction System. Pump, flow control valves, automatic switching valves, and flowmeter.

5.3 Filter(In-lfne). Abinder-free, glasfiber filter with a porosity of 3 to 5 mIcronz should be immediately downstream from the sample pump.

5.4 Stripper or Precolumn.Located out- side of the oven at ambient temperature. The column should be repacked or replaced after theequivalent of2 months ofcontinu-

ous operation.

5.5 Oven. For containing the analytical column and catalytic converter. The oven should be capable ofmaintaining an elevated temperature constant within ±0.5* C. The specific temperature varies with instrument manufacturer.

6. Reagents. 6.1 Combustion Gas.Air containing less than 1.3 mg./m.S (2 p.pm.) hydrocarboll as methane.

6.2 Fuel.Hydrogen ora mixture ofhydrogen and inert gas containing lessthan 0.065 mg./m.3 (0.1 p.pm.) hydrocarbons as methane.

6.3 CarrierGas. Helium, nitrogen, air or hydrogen containing less than 0..065 mg./m. 8 (0.1 p.p~m.) hydrocarbons as methane.

6.4 Zero Gas. Air containing less than 0.065 mg./m.3 (0.1 p.p~m.) total hydrocarbons

as methane.

6.5 Calibration Gases. Gases needed for linearity checks (peak heights) are determined by the ranges used. Calibration gases corresponding to 10, 20, 40, and 80 percent of full scale are needed. Gases must be provided with certification or guaranteed analysis. Methane Is used for both the total hydrocarbon measurement and methane measurement.

6.6 Span Gas.The calibration gas corre- sponding to 80 percent of full scale is used to,span the instrument.

7. Procedure. 7.1 Calibrate the Instrument as described in 8.1. Introduce sample into the system under the same conditions of pressure and flow rates as are used in calibration. (The pump is bypassed only when pressurized cylinder gases are used.) Figure El shows a typical flow diagram; for specific operating instructions referto manufacturer's manual

8. Calibration. -8.1 Calibration Curve. Determine the linearity ofthe system for THC and methane in thebarographic modeby introducing zero gasand adjustingtherespective zeroing con- trols to indicate a recorder reading of zero. Introduce the span gas and adjust the span control to indicate the proper value on the recorder scale. Recheck zero and span until adjustments are no longer necessary. Introduce intermediate calibration gases and plot the values obtained. If a smooth curve Is not obtained,calibration gasesmayneedreplace- ment.

9.Calculation. 9.1 Determine concentrations of total hydrocarbons (asCH,) andCH,, directly from the calibration curves. No calculations are necessary. 

### 9.2 Determine concentration of hydrocarbons corrected formethaneby subtraoting the mbthane concentration from the total hydrocarbon concentration.

9.3 Conversion botween p.p.m. and mg,/ in.S values for total hydrocarbons (ms CH,) methane and hydrocarbons correoted for methane are made as follows:

p.p.m. carbon (as CH4=[mg. carbon (as 

### CH)/m.8 X1.53
10. Bibliography. Fee, G., "Multi-Parameter Air Quality Analyzer", ISA Proceedings AID/OHLA'PID Symposium, Houston, Texas, April 10-21, 1971.



### Villalobos, R., and Chapman, n. L., "A Oas Chromatographic Method for Automatic Monitoring of Pollutants in Ambient Air", Ibid.

Stevens, n. X., "The Automated Gas Chromatograph as an Air Pollutant Monitor", 1970 Conference on Environmental Toxicology, U.S. Air Force, Wrlght-Pattereon AirForce Base,Dayton, Ohio.

Stevens, R. K., and O'Kceffo, A. V., Anal. Chem.42, 143A (1970).

Schuck, E.A., Altshuller,A. P., Barth, D, S. and Morgan, G. B., "Relationship of Hydrocarbons to Oxidants In Ambient Atmospheres", J. AirPoll. Cont.Assoo. 20, 297-302 (1970).

Stevens, R.K,, O'Eeeffe, A. V.,and Ortman, G. C., "A Gas Chromatographic Approach to the Semi-Continuous Monitoring of Atmospherio Carbon Monoxido and Methane", Proceedings of 11th Conference on Methods in AirPollution on Industrial Hygiene Studies, Berkeley, Calif., March 30-April 1, 1070,



### Swinnerton, J. W., Linnenbom, V. J. and Check, C. H., Environ. Sed. Tcchnol. 3, 830 

### (1069).

Williams, 1. G., Advances in Chromato

### raphV, Giddings, J. C,,and Keller, n. 

### A., edItors, Marcell Dekker, N.Y. (1960), pp. 178- 182.



### Altshuller, A. P., Kopcznsld, S. L., Lonnamn, W. A., Becker, T. L. and Slater, n., 

### Environ.Sd. Technol.1, 899 (1907).

Altshuller, A. P., Cohen, 

### t, n., and Purcell, T. C.,Can.J.Chem., 44,2973 (1060).

DuBols, L., Zdrojowskl, A., and Monlann,
.T.

L.,J. AirPoll. Cont.Assoc, 10, 130 (1060). Ortman, G. 0., Anal. Ohem. 38, 641-010 

### (1066).

Porter, K., andVolmann, D.H.,Anal.Chem, 34,748-749 (1962).

Crum, W. M., Proceedings, National Analysis Instrumentation Symposium ISA, 1002.

Schwink, A., Hochenborg, H., and Forderreuther, M., Brennstoff-Chemo 72, No. 0, 205 

### (1061).

Instruction Manual for Air Quality Chromatograph Model 6800, Beckman Instrument Co., Fulerton, Calif.

Instruction Manual, Bendix Corp., ionceverte,W.Va.

Instruction Manual, Byron Instrument Co,, Raleigh, N.C.

MSA Instruction Manual for GO Process Analyzer for Total Hydrocarbon, Methano and Carbon Monoxide, Pittsburgh, Pa.

Monsanto Enviro-hom System for Total Hydrocarbons, Methane and Carbon Monoxide Instruction Manual, Dayton, Ohio,

Union Carbide Inrtructlon Manual for Model 3020 Gas Chromatograph for COCHC-T/1, WhitePlains,N.Y.

Instruction Manual for 350 V Analyzer, Tracer Inc., Austin,Tex.

FEDEIAL REGISTER. VOL 36. NO. 84-FRIDAY,APRIL 30, 1971 

# 8198

"! • f

## RULES AND REGULATIONS

ALUMUU!,
C-In. PEN-RAY BOY Et:CLO:'URE 

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QUARTZ TUBE, 15-m 0.0. 

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FigureD2. Ozenocourco.



# 1 FLO'[METER

(0-10 Ilter..min)

NEEDLE VALVE


# I FLOW



## CONTROLLM

Ffgure D3. Ozonecalibration airoupply. souco, ani manifold syst"

.

FEDERAL REGISTER, VOL 36, NO. 84-FRIDAY, APPIL 30, 1971 

### S 

## litcrckri!n 

# A-"IR



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## $S199 

# G

# 8200 RULES AND REGULATIONS

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4cP0+0 

### 0 p C; 0 P.Vsamples collected from a standard test atmosphere. Precision would probably be different when the analysis is performed manually.

4.2 No accuracy data are available. 4.3 Samples are stable foratleast 6weeks. 5. Apparatus. 5.1 Sampling.See Figure Fl. 5.1.1 Absorber.Polypropylene tubes 164 x 32 mm., equipped with polypropylene twoport closures.* Rubber stoppers cause high and varying blank values and should not be used. A gas dispersion tube with a fritted end ofporosity B (70-100 pm. maximum pore diameter) is used.

5.1.1.1 Measurement of Maximum Pore Diameter ofFrit. Carefully cleanthe fritwith dichromate-concentrated sulfuric acid cleaning solution and rinse well with distilled
water. Insert through one hole of a two-hole rubber stopper andinstallin a test tube containing sufficient distilled water to cover the fritted portion. Attach a vacuum source to the other hole of the rubber stopper and

measure the vacuum required to draw the firstperceptible streamofairbubblesthrough the frit. Apply the following equation:

30s maximum pore diameter, pm.=

-
s=Surface tension of water in dynes/cm. atthe test temperature (73 at 18- C., 72 at 25* C., and 71 at 310 C.). P=Measured vacuum, am. Hg.

5.1.2 Probe. Teflon, polypropylene, or glass tubewith a polypropylene or glassfunnel at theend and a membrane filterto protect the frit. Replace filter after collecting five samples, or more often as indicated by visual observation of theloading.

5.1.3 Flow ControlDevice. Calibrated 27- gauge hypodermic needle, three-eighths of

an inch long to maintain a flow of approximately 0.2liter/minute. The needleshould be protected by a membrane filter.Change filter after collecting 10 samples.

5.1.4 Air-Pump. Capable of maintaining

a flow of 0.2 liter/minute through the absorber, and a vacuum of 0.7 atmosphere.

5.1.5 CalibrationEquipment.Glass flowmeter formeasuring airflows up to approximately 275 mL/min. within ±h2 percent, stopwatch, and precision wet test meter (1 liter/revolution).

-

5.2 Analysis. 5.2.1 Volumetric Flasks.50, 100, 200, 250. 500, 1,000 ml.

5.2.2 Graduated Cylinder. 1,000 ml. 5.2.3 Pipets.1,2, 5, 10, 15 ml.volumetric; 2 ml., graduated in 1/10 ml. intervals.



### 5.2.4 TestTube.
5.2.5 Spectrophotometer of Colorimeter. Capable ofmeasuring absorbance at 540 am. Bandwidth is not critical.



### 6. Reagents. 6.1 Sampling. 

### 6.1.1 Absorbing Reagent.Dissolve 4.0 -g. sodium hydroxide in distilled water and dilute to 1,000 ml.

6.2 Analysis. 6.2.1 Sulfanilamide. Dissolve 20 g. sulfanilamide in 700 ml. distilled water. Add. withmixing, 50 ml. concentrated phosphoric acid (85 percent) anddiluteto 1,000ml. This solution is stable for a month if refrigerated.

6.2.2 NEDA Solution. Dissolve 0.5 g.N-1- naphthylethylenediamine dihydrocbloride in distilled water. This solution is stable for a month if refrigerated and protected from light.

6.2.3 Hydrogen Peroxide.Dilute 0.2 ml. 30 percent hydrogenperoxide to 250 ml. with distilled water.This solution maybeused for

a month if protected from light.

6.2.4 Stan4ardNitriteSolution. Dissolve sufficient desiccated sodium nitrite (NaNOz,

'Available from Bel-Art Products, Pequannbck, N.J. 

## RULES AND REGULATIONS

assay of 97 percent or greater) and dilute with distilled water to 1.000 ml. s that a solution containing 1.000 pg. NO mL L--obtained. The amount ofNallO2 to use Calculated as follows:

G= --- YZ 100 

### A G=Amount ofNONO:. g. 1.500=Gravlmetrlc factor in can'erting NO, into NaNO. A=Aszy, percent.
7. Procedure. 7.1 Sampling. Assemblo the -ampllng train as shown In Figure Fl. Add 50 ml. absorbing reagentto theabsorber.Disconnect funnel, insert calibrated flowmeter, and

measure flow before sampling. If flow rate before sampling is less than 83 percent of needle calibration, check for leak or change filters as necessary. Remove flowmeter and replace funnel. Sample for 24 hours from midnight to midnight and measure flow at end of sampling period.

7.2 Analys s. Replace any water lo3t by evaporation during sampling. Pipet 10 ml. of the collected sample into a te3t tube. Add 1.0 ml. hydrogen peroxide colution, 10.0 ml. sulfanilamide solution, and 1.4 ml. NEDA solution with thorough mixing alter the addition of each reagent.Prepare a blank In the same manner using 10 ml. absorbing reagent.Aftera 10-minute color-development interval, measure the absorbance at, 140 mm. against the blank. Read pg. NO imL from standard curve (Section 8.2).

8. Calibration andEflciencies. 8.1 Sampling. 8.1.1 Calibrationof Flowmctcr.Using a wet test meter and a stopwatch, determine the rates of airflow (ml./min.) through the flowmeter at several ball pofitions. Plot ball positions versus flow rates.

8.1.2 Calibrationo1 Hypodermf N eedlc. Connect the calibrated flowmeter, the needle
to be calbrxted, and the source of vacuum in such a way that the direction of airflow through the needle is the same as In the sampling train. Read the position of the ball and determine flow rate In mL/min. from the calibration chart prepared In 8.1.1. Reject all needles not having flow rate3 of 190 to 210 ml./min. before sampling.
ME1MRAtIE FILTER 

## &901

8.2 Calration Ctrre.Dilute 5.0 ml. of the. 1,00 [g. NO7Jml. slution to 200 ml. with absorbing regent. This solution contiln 23 pg. 1O;,ml. Pipet 1. ,5, and 15 ml. of the 25 pg.NOJmL. solution into 50-, 50-. 100-. and250-mi. volumetricflasks anddilute
to the mark with absorbing reagent. The rolutions contain 0.50, 1.00, 1.25, end I0
pg. 170Oml., re--pecively. Run standards as instructed in '7.2. Plot absarbance vs. -g.

8.3 Effle encCe3. An overall average effclency of 35 per cent v.-a obtained from test atmnopheres having nitrogen dioxide concentratlons of 140pg./m. 2 and200 

### g.fm.F by automatedanaly3ls.(2)

9. Calculation. 9.1 Sampling. 9.1.1 Calculate volume ofair ampled.



### 2
V=Volume ofair ampled.m.2


### F1

### =? easured floW rate before sampling.
Mi./mln. P=Me in.ured flow rate after sampling.

T=Tlmoof ampling,mi. 10-=Convercion ofmLtoin.' 9.2 Caculate the concentration of nitrogen diodde a3 g. N1O,/m.

-,-~ r = (,g.NOj ml.) p450
(Ag.NOfml.) 143 V

50=Volume ofabsorblng reagent uzed in sampling.ml. V=Volumo ofairsmpled,m. 0,3=ElcIenc7. 9.2.1 If dezired, concentration ofnitrogen dioxidemaybe c3lculated as ppxm.NO. p.mpM.=(g.NOfm) -5.32 X10-1 10. Refercn.ees. 

### (1) Jacobo, M.B., and Hochhelser, S., "Continuou3 Sampling and Ultramicrodetermination ofNitrogen Dioxide in Air",Anal.Cl m., 30 420 (1953). (2) Purdue, L. 3., Dudley, T. E.. Clements, J. B.. andThompoon, R. J.. "Studies in Air Sampling for Nitrogen Dioxide," L A reinve tIgation of the JacobsHcchhelser ReaZent. In Preparation. 

### 2_A FILTER

[1-.sa Fl. -. W18.

FEDERAL REGISTER, VOL. 36, NO. 14--FRIDAY, APRIL 30, 1971