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1、 CGA G-8.22007 COMMODITY SPECIFICATION FOR NITROUS OXIDE FIFTH EDITION COMPRESSED GAS ASSOCIATION, INC. 4221 Walney Road, 5th Floor Chantilly, VA 20151 Phone: 703-788-2700 Fax: 703-961-1831 E-mail: PAGE ii COMPRESSED GAS ASSOCIATION, INC. CGA G-8.22007 PLEASE NOTE: The information contained in this
2、 document was obtained from sources believed to be reliable and is based on technical information and experience currently available from members of the Compressed Gas Association, Inc. and others. However, the Association or its members, jointly or severally, make no guarantee of the results and as
3、sume no liability or responsibility in connection with the information or suggestions herein contained. Moreover, it should not be assumed that every acceptable commodity grade, test or safety procedure or method, precaution, equipment or device is contained within, or that abnormal or unusual circu
4、mstances may not warrant or suggest further requirements or additional procedure. This document is subject to periodic review, and users are cautioned to obtain the latest edition. The Associa- tion invites comments and suggestions for consideration. In connection with such review, any such comments
5、 or suggestions will be fully reviewed by the Association after giving the party, upon request, a reasonable op- portunity to be heard. Proposed changes may be submitted via the Internet at our web site, . This document should not be confused with Federal, state, provincial, or municipal specificati
6、ons or regulations; insurance requirements; or national safety codes. While the Association recommends reference to or use of this document by government agencies and others, this document is purely voluntary and not binding. A listing of all publications, audiovisual programs, safety and technical
7、bulletins, and safety posters is available via the Internet at our website at . For more information contact CGA at Phone: 703-788-2700, ext. 799. E-mail: . Work Item 05-18 Medical Gases and Equipment Committee NOTETechnical changes from the previous edition are underlined. FIFTH EDITION: 2007 FOURT
8、H EDITION: 2000 THIRD EDITION: 1994 SECOND EDITION: 1989 2007 BY THE COMPRESSED GAS ASSOCIATION, INC. All materials contained in this work are protected by United States and international copyright laws. No part of this work may be reproduced or transmitted in any form or by any means, electronic or
9、 mechanical including photocopying, recording, or any informa- tion storage and retrieval system without permission in writing from The Compressed Gas Association, Inc. All requests for permission to reproduce material from this work should be directed to The Compressed Gas Association, Inc., 4221 W
10、alney Road, Suite 500, Chantilly VA 20151. You may not alter or remove any trademark, copyright or other notice from this work. CGA G-8.22007 COMPRESSED GAS ASSOCIATION, INC. PAGE iii Contents Page 1 Scope .1 2 Classification 1 2.1 Types.1 2.2 Quality verification levels.1 2.3 Quality tests.1 3 Qual
11、ity verification systems3 3.1 Production qualification tests.3 3.2 Lot acceptance tests3 4 Sampling 4 4.1 Sample size.4 4.2 Gaseous samples4 4.3 Liquid samples.4 5 Analytical procedures.5 5.1 Parameters of analysis5 5.2 Ammonia content.6 5.3 Carbon dioxide content6 5.4 Carbon monoxide content .6 5.5
12、 Halogen content 7 5.6 Hydrocarbon content (C1-C5).7 5.7 Nitrogen content7 5.8 Nitrogen and oxygen (air) content.7 5.9 Nitrogen oxides content (NO and NO2) .7 5.10 Oxygen content .7 5.11 Percent nitrous oxide.8 5.12 Water content8 5.13 Identity.8 6 Containers8 6.1 Nitrous oxide containers8 6.2 Conta
13、iner preparation9 6.3 Nitrous oxide (USP).9 6.4 Valves on nitrous oxide containers9 7 Supplemental specification data.10 7.1 Moisture conversion data 10 7.2 Assay conversion data 12 8 References.12 Tables Table 1Directory of limiting characteristics (units in ppm (v/v) unless otherwise shown)2 Table
14、 2Typical uses.2 Table 3Moisture conversion data 10 Table 4Assay conversion data 12 -,-,- This page is intentionally blank. -,-,- CGA G-8.22007 COMPRESSED GAS ASSOCIATION, INC. PAGE 1 1 Scope This publication describes the specification requirements for nitrous oxide manufactured by various commerci
15、al processes. The term container as used in this publication shall refer to portable compressed gas cylinders and liquid containers made in accordance with Title 49 of the U.S. Code of Federal Regulations (49 CFR) Parts 100-180; Transport Canadas (TC) Transportation of Dangerous Goods Regulations; o
16、r ASME Boiler whereas contaminants such as nitrogen dioxide, ammonia, and chlorine are concentrated in the liquid phase. It is therefore important that a two-phase sample be analyzed in an analytical sequence that will not materially reduce contaminants to be determined in subsequent procedures. The
17、 analytical proce- dures are listed in a sequence that will minimize concentration changes. Analytical sequence may be altered as agreed to by the supplier and the customer for non-USP nitrous oxide. 2) Unless otherwise specified, the sample shall be obtained from the vapor phase of the container or
18、 as agreed to by the sup- plier and the customer. 3) For USP quality verification, the percent nitrous oxide shall be defined as the difference between 100% and the percent air. This test is performed last in the sequence of USP tests after all other trace constituents have been determined. 4) For U
19、SP quality verification, perform the verification tests in the sequence listed (after the filled container has warmed to ambient temperature); a gas/liquid equilibrium must be established in the container. For a vapor sample, test nitrous oxide gas from the vapor phase of the container; for a liquid
20、 sample, a representative vaporized sample of the liquid phase must be obtained. The sequence listed minimizes concentration changes and allows for maximum detection of toxic contami- nants on the assumption that the usage is inhalation. Table 2Typical uses Quality verification level (QVL) Typical u
21、ses A Medical/USP B General commercial uses C Semiconductor NOTETypical uses defined in this table are not all-inclusive. -,-,- CGA G-8.22007 COMPRESSED GAS ASSOCIATION, INC. PAGE 3 3 Quality verification systems 3.1 Production qualification tests These tests are a single test or a series of analyse
22、s performed on the product to ensure the reliability of the production facility to supply nitrous oxide of the required QVL. This production qualification can be verified by the analytical records of product from the supplier or, if required, by the analysis of representative samples of the product
23、from the facility at appropriate intervals as agreed to by the supplier and the customer. Production qualification tests can be performed by the supplier or by a laboratory agreed to by the supplier and the cus- tomer. 3.1.1 Analytical requirements of the production qualification tests Analytical re
24、quirements of the production qualification tests include the determination of all the limiting charac- teristics of nitrous oxide. 3.1.2 Compliance with U.S. Pharmacopeia and National Formulary To comply with the General Notices requirements of the U.S. Pharmacopeia and National Formulary (USPNF), t
25、ests suitable for detecting the occurrence of other impurities, the presence of which is inconsistent with applicable manufacturing practice or good pharmaceutical practice, should be used in addition to the tests provided in the USP monograph 6. 3.2 Lot acceptance tests These tests are analyses per
26、formed on the nitrous oxide in a shipping container, or a sample thereof, that is representative of the lot. 3.2.1 Lot definitions Selection of the appropriate lot definition may be subject to regulations for some QVLs. One of the following shall be used: no specific quantity or any quantity of nitr
27、ous oxide agreed to by the supplier and the customer; all the nitrous oxide supplied during the contract period; all the nitrous oxide supplied or containers filled during a calendar month; all the nitrous oxide supplied or containers filled during 7 consecutive days; all the nitrous oxide container
28、s filled during a 24-hour period; all the nitrous oxide supplied or containers filled during a continuous workshift; all the nitrous oxide supplied in one shipment; all the nitrous oxide supplied in one shipping container; all the nitrous oxide in the container(s) filled from one unreplenished bulk
29、container; or all the nitrous oxide supplied or containers filled during an uninterrupted filling sequence. 3.2.2 Number of samples per lot The number of samples per lot shall be in accordance with one of the following: one sample per lot; or any number of samples agreed to by the supplier and the c
30、ustomer. PAGE 4 COMPRESSED GAS ASSOCIATION, INC. CGA G-8.22007 4 Sampling 4.1 Sample size The quantity of nitrous oxide in a single sample container should be sufficient to perform the analyses for all the limiting characteristics. The filled sample container must be allowed to reach ambient tempera
31、ture before test- ing. If a single sample does not contain a sufficient quantity of nitrous oxide to perform all of the analyses for the required QVL, additional samples from the same lot shall be taken under similar conditions. Withdraw the sample for the tests with the least possible release of ni
32、trous oxide consistent with proper purging of the sam- pling apparatus. CAUTION: The American Conference of Governmental Industrial Hygienists (ACGIH) recommends a Thresh- old Limit ValueTime-Weighted Average (TLVTWA) of 50 ppm (90 mg/m3) for nitrous oxide. The TLVTWA is the time-weighted average co
33、ncentration for a normal 8-hour workday and a 40-hour workweek to which nearly all workers may be repeatedly exposed, day after day, without adverse effect 7. CAUTION: For safety reasons, sample cylinders shall conform to ASME code specifications or DOT or TC regulations and shall not be filled to a
34、 quantity greater than 68% of their water capacity by weight, the maximum fill density allowable. See 49 CFR Parts 100-180 or Canadian Standards Association B340, Selection and Use of Cylinders, Spheres, Tubes, and Other Containers for the Transportation of Dangerous Goods, Class 2 1, 8. The minimum
35、 service pressure rating of the cylinders must be 1800 psig 12 410 kPa).2 4.2 Gaseous samples Gaseous samples shall be representative of the nitrous oxide supply. Samples shall be obtained in accordance with one of the following: By selecting the first container filled as the representative containe
36、r from the containers filled in the lot. The container should be checked by weight to be sure that it is filled to the maximum allowable fill density (68% water capacity by weight); By connecting the gaseous phase of the container being sampled directly to the analytical equipment using suitable pre
37、ssure regulation to prevent overpressurizing this equipment; or CAUTION: For safety reasons the sampling system shall have a rated service pressure at least equal to the pressure in the supply container. By filling the sample cylinder from the vapor phase. The sample cylinder shall be double-ended w
38、ith a valve on each end. There shall be a purge valve on the sample line immediately before the sample cylinder to purge the sample line. Fill the sample cylinder by first opening the inlet valve, then the discharge valve. After adequate purging, close the discharge valve and then the inlet valve. 4
39、.3 Liquid samples Liquid samples shall be representative of the nitrous oxide supply. Samples shall be obtained in accordance with one of the following: CAUTION: Provide adequate pressure relief devices to prevent possible hydrostatic rupture from liquid-filled lines and overfilled sampling cylinder
40、s. By selecting a representative container from the containers filled in the lot. The container should be checked by weight to be sure that it is filled to the maximum allowable fill density (68% water capacity by weight). Connect the liquid phase directly to the analytical equipment using suitable
41、flash vaporization and pressure regulation; By filling the sample cylinder using standard cylinder filling equipment (equipped with suitable pressure relief devices and a high pressure gauge), and adequately purging the system by filling other containers or 2 kPa shall indicate gauge pressure unless
42、 otherwise noted as (kPa, abs) for absolute pressure or (kPa, differential) for dif- ferential pressure. All kPa values are rounded off per CGA P-11, Metric Practice Guide for the Compressed Gas Industry 9. CGA G-8.22007 COMPRESSED GAS ASSOCIATION, INC. PAGE 5 otherwise flowing liquid through the sy
43、stem. The cylinder shall be checked immediately by weight to be sure that it is not filled to more than 68% of its water capacity by weight (see second Caution under 4.1); By filling the sample cylinder from the liquid phase. The sample cylinder shall be double-ended with a valve on each end. There
44、shall be a purge valve on the sample line immediately before the sample cylinder to purge the sample line. Fill the sample cylinder in a horizontal position by first opening the inlet valve, then the discharge valve. When nitrous oxide escapes, close the discharge valve, then immediately close the i
45、nlet valve. Disconnect the cylinder and promptly check its weight. If filled to more than 68% of the water capacity by weight, immediately vent liquid from the cylinder until the correct weight is achieved (see sec- ond Caution under 4.1 and Caution under 4.3); By connecting a properly prepared samp
46、le cylinder to a liquid line and closing the sample cylinder valve as soon as flow into the cylinder stops. The sample cylinder may be precooled to increase the volume of the sample. The cylinder shall be checked by weight to be sure it is not filled to more than 68% of its water ca- pacity by weigh
47、t. If overfilled, immediately vent liquid from the cylinder until the correct weight is achieved (see second Caution under 4.1 and Caution under 4.3); or By direct connection between the liquid phase of nitrous oxide and the analytical equipment using suitable flash vaporization. This sampling techn
48、ique is not recommended for determining water or dew point. 5 Analytical procedures 5.1 Parameters of analysis The parameters for analytical techniques contained in this section are: 5.1.1 Percent percent (v/v) = parts per hundred by volume. 5.1.2 Parts per million ppm (v/v) = parts per million by v
49、olume. 5.1.3 Water/dew point Water, measured in ppm (v/v) or as dew point in degrees Fahrenheit, is expressed at one atmosphere absolute (101 kPa, abs). To convert to other units, see Table 3. 5.1.4 U.S. Pharmacopeia U.S. Pharmacopeia (USP) refers to the test requirements for air contained in the most recent edition of the USP