SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT

APPLIED SCIENCE & TECHNOLOGY DIVISION

LABORATORY SERVICES BRANCH

SCAQMD METHOD 316A-92

DETERMINATION OF VOLATILE ORGANIC COMPOUNDS (VOC) IN MATERIALS

USED FOR PIPES AND FITTINGS

Approved September 9, 1992

Revised June 1993

Revised December 1995

Revised October 1996
This method is used to determine the volatile organic compounds (VOC) in materials used for pipes and fittings. The method is applicable to materials regulated as reactive diluents under rules in Regulation XI.

CONTENTS

1. Principle

2. Equipment 1

3. Reagents and Materials 1

4. Analytical Procedure 2

4.1 Determination of VOC 2

4.2 Preparation of the pipe-joint assembly 2

4.3 Determination of VOC retained

as part ofthe finished product 2

4.4 Determination of VOC emitted by

blank pipe 3

5. Calculations 4

6. Precision (For samples that do not

contain water or exempt compounds) 5
An aliquot of the material is analyzed for VOC by the procedure specified in SCAQMD

Method 304. Another portion of the material is applied to a substrate specified by themanufacturer and cured in accordance with Section 4.3.8. After curing, the assembly is

heated for one hour at 110°C. The VOC retained and the VOC emitted is then determined.

The VOC value for compliance to SCAQMD regulations is dependent upon the amount of

VOC retained on the substrate.

2. Equipment

2.1 Laboratory exhaust hood

2.2 Balance, analytical, capable of weighing accurately to 0.1 mg

2.3 Pipe cutter, hacksaw, capable of cutting pipes of diameter of 2.5 inches or less

2.4 Other equipment: refer to relevant individual methods in SCAQMD Method 304

manual for other equipment needed.

2.5 Oven, forced draft, capable of maintaining the temperature at 110°C for at least one

hour. Refer to ASTM D2369 for specifications.

3. Reagents and Materials

3.1 Substrates for currently identified applications:

1/2” diameter PVC, Schedule 40

2” diameter ABS, Schedule 40

3/4” diameter CPVC, Schedule 80

3.2 Straight connectors, slip/slip, of the same material as the test pipe. Inner diameter

ofthe straight connector to be the same as outer diameter ofthe test pipe.

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4. Analytical Procedure

4.1 Determination of VOC

4.1.1 The VOC content of the uncured material is determined using SCAQMD

Method 304-91. This VOC expressed in percent by weight is VOC as

determined in SCAQMD Method 304-91, Section 5.3.

4.2 Preparation ofthe pipe-joint assembly

4.2.1 Cut two 3 1/2 inch pieces of the appropriate pipe.

4.2.2 Clean joint and pipes with paper towel or kimwipes until they are free of

dust and any other extraneous material.

4.2.3 Weigh the pipe-joint assembly to the nearest 0.1 mg (Wai).

4.3 Determination of VOC retained as part of the finished product

4.3.1 Material must be in a 1/4 pint container with an applicator swab.

4.3.2 Wipe clean the material container to remove dust and weigh to the

nearest 0.1 mg (W).

4.3.3 Steps 4.3.4 through 4.3.6 must be completed in 2 minutes.4.3.4 Open the tared material container taking care not to spill any material.

Carefully apply without spilling, a smooth uniform coating around the

outside edges of both PVC pipes. Similarly apply material to the inside

walls ofthe joint.

4.3.5 Immediately return the applicator brush to the can and close the lid tight.

4.3.6 Complete the assembly by pushing the coated ends of the pipes into the

joint.

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to 85

F under the hood.

4.3.9 Heat the assembly in the oven at 110°C for 1 hour.

4.3.10 Cool to room temperature in a desiccator.

4.3.11 Weigh the assembly to the nearest 0.1 mg (Waf).

4.3.12 Repeat steps 4.2 to 4.3.11 six times.

4.3.13 Proceed to Section 5 for calculations.

4.4. Determination of VOC emitted by blank pipe (Note: run concurrently with sample

analysis)

4.4.1 Prepare a pipe-joint assembly as in Section 4.2.

4.4.2 Complete the assembly by pushing the pipes into the joint.

4.4.3 Weigh the pipe-joint assembly to the nearest 0.1 mg (Wbi)

4.4.4 Follow Sections 4.3.8 to 4.3.10.

4.4.5 Weigh the assembly to the nearest 0.1 mg (Wbf).

4.4.6 Repeat steps 4.4.1 to 4.4.5 two times.

4.4.7 Calculate the grams of VOC emitted by the pipe assembly, Wb,

according to Section 5.1.

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Wbj

5.2 Correction value of weight loss due to pipe assembly,W, in grams:

Waj

W= X E (Wb)n

3 n=1

5.3 The weight percent total volatiles (TV) emitted for each run:

[(W) - (Waf Waj) -Wj X 100

TV= c

5.4 The weight percent water and exempt compounds (Exem) in the total volatiles

emitted, if applicable:

Exem = (EX x TV)/100

5.5 The actual weight percent VOC emitted (VOCae) is:

VOCae TV - Exem

5.6 The weight percent of VOC retained as integral part ofthe assembly (VOCr) for

each run:

(VOC 5- VOCae) X 100

VOCr

=

VOC 5

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Note: For equation 5.7, use the average ofseven runs from 5.5 for VOCae.

5.8 Definition ofterms:

Wbj = Initial weight of blank assembly, g, (Section 4.4.3)

Wbf = Final weight of blank assembly, g, (Section 4.4.5)

W5 Weight of material used to coat assembly (W - Wsf), g

W5 = Initial weight of material container, g, (Section 4.3.2)

Wsf = Weight of material container after application, g, (Section 4.3.7)

Wai = Initial weight of assembly, g, (Section 4.2.3)

Waf = Weight of assembly after heating, g, (Section 4.3.11)Dm = Density of material by SCAQMD Method 304-91, gImL

VOC Weight percent VOC obtained by SCAQMD Method 304-91

EX = Sum ofthe weight percent water and weight percent exempt

compounds in the material, determined by SCAQMD Method304-91.

5.9 Determination ofthe VOC ofthe material for compliance.

5.9.1 To determine compliance to the requirement of Rule 1168, the VOC

value will be calculated as specified by the Rule.

6. Precision (For samples that do not contain water or exempt compounds)

6.1 Repeatability (Single Analyst)

6.1.1 The estimated coefficient of variation of results (each the average ofseven

replicate determinations), obtained by the same analyst on different days is

listed in Table 1.

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6.2.1 The estimated coefficient of variation of results (each the average ofseven

replicate determinations), obtained by analysts in different laboratories is

listed in Table 2.

6.2.2 The 95% limit for the difference between two such averages is also listed

in

Table 2.

C,,

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Cement Estimated Coefficient Degrees of 95% limit for Type of Variation, % Freedom difference, relative % relative

ABS 2.3 14 5.0

CPVC 2.7 14 5.8

PVC 3.4 13 7.3

Table 2

Reproducibility ( Multilaboratory)

Cement type Estimated Coefficient Degrees of 95% limit for

of Variation, % Freedom difference, relative % relative

ABS 11.1 5 29

CPVC 9.4 5 24

PVC 6.8 5 17

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n