1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2017 SAE International All rights reserved. No part of this p
3、ublication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-497
4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/standards.sae.org/J2773_201702 SURFACE VEHICLE STANDARD J2773 FEB2017 Issued 2011-02 Revised 2017-02Superseding J
5、2773 FEB2011 Standard for Refrigerant Risk Analysis for Mobile Air Conditioning Systems RATIONALE Update of the Standard to include references to United States Environmental Protection Agency (EPA) Significant New Alternatives Policy (SNAP) acceptable use conditions. This Standard was originally dev
6、eloped to facilitate and standardize the safe introduction and proper handling of new refrigerants. FOREWORD The potential impact of unintended refrigerant discharges resulting in high refrigerant concentrations shall be investigated and considered. All reasonable hazards affecting persons inside th
7、e vehicle and in the close proximity of the vehicle, as well as the effects of long-term exposure shall be considered. Possible failure scenarios and safety targets shall also be considered. 1. SCOPE This Standard describes methods to understand the risks associated with vehicle mobile air condition
8、ing MAC systems in all aspects of a vehicles lifecycle including design, production, assembly, operation and end of life. Information for input to the risk assessment is provided in the Appendices of this document. This information should not be considered to be complete, but only a reference of som
9、e of the data needed for a complete analysis of the risk associated with the use of refrigerants in MAC systems. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this specification to the extent specified herein. Unless otherwise indicated, the latest issue of SAE pub
10、lications shall apply. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.org. SAE J639 Safety Standards for Motor Vehicle Vapor Compression Refrigerant System
11、s SAE J1739 Potential Failure Mode and Effects Analysis in Design (Design FMEA), Potential Failure Mode and Effects Analysis in Manufacturing and Assembly Process FMEA) SAE J2683 Refrigerant Purity and Container Requirements for Carbon Dioxide (CO2 R-744) Used in Mobile Air-Conditioning Systems SAE
12、INTERNATIONAL J2773 FEB2017 Page 2 of 6 SAE J2772 Measurement of Passenger Compartment Refrigerant Concentrations Under A/C System Refrigerant Leakage Conditions SAE J2844 R-1234yf New Refrigerant Purity and Container Requirements Used in Mobile Air-Conditioning Systems 2.1.2 Other Publications ISO
13、13043 Road vehicles - Refrigerant systems used in Mobile Air Conditioning systems (MAC) - Safety requirements 2.2 Legal Requirements The United States Environmental Protection Agencys SNAP regulation defines accepted refrigerants for the use in MAC Systems. The listed substances may require use cond
14、itions (accepted with use conditions). The full SNAP list with refrigerants and potential use conditions can be found in the US federal register at - US EPA 40 CFR Part 82 Subpart G Appendix B. All motor vehicles automotive refrigerants may be subject to and must comply with all legal regulations as
15、 required by local, national or international authorities. 3. GENERAL DEFINITIONS Safety is the absence of non-acceptable risks. Non-acceptable risks are those that are higher than those already accepted by the general public today (e.g., risks involved with riding in an airplane are considered acce
16、ptable by general public today). Risk: Combination of probability of a harm occurring during an event and the severity of it. FTA Fault Tree Analysis is a methodology that graphically presents the sequences and combinations of failures that lead to a particular outcome. It utilizes a “top-down“ appr
17、oach, starting with the undesired effect as the top event of a tree of logic. Each situation that could cause that effect is added to the tree as a series of logic expressions. This technique analyzes the potential combinations or sequences of events by which an undesired event may occur. FTA can co
18、nsider such causal effects as human error, equipment failure, and operating and maintenance procedures, though it cannot cover those causes of system failure that cannot be envisioned by risk analysts (Blackwell et al., 2006). FTAs consist of various event “boxes“, which reflect the probability or f
19、requency of key events leading up to a system failure. The event boxes are linked by connectors (“gates“) which describe how the contributing events may combine to produce the failure. General Safety Process Requirements - Proper design practices for the application of a refrigerant to MAC systems a
20、re required. The following or other equivalent methods shall be used to assess the risks associated with the use of a new refrigerant proposed for use in mobile air conditioning systems. SAE J1739 - Potential Failure Mode and Effects Analysis in Design (Design FMEA), Potential Failure Mode and Effec
21、ts Analysis in Manufacturing and Assembly Processes (Process FMEA), or equivalent shall be applied to the design and development of mobile air conditioning refrigerant systems. SAE INTERNATIONAL J2773 FEB2017 Page 3 of 6 4. SAFETY ASSESSMENT This standard provides the guidelines for an assessment of
22、 safety with the refrigerants referenced in this standard for mobile air-conditioning systems. The management of functional safety shall include the following from the concept phase through the lifetime of the vehicle 1. Concept phase 2. Product development phase 3. Production and assembly 4. Operat
23、ion 5. Service 6. End of life and scrapping 5. RISK ASSESSMENT Risk characterization represents the step in the analysis where all data (analytical and empirical) on acute and chronic toxicity, flammability and anticipated air concentrations are brought together to quantify the potential risks of th
24、e refrigerant system. The results of the risk characterization contribute to the FTA and/or DFMEA and allow an estimate of the impact of adverse events that may result from use of the refrigerant. Risk assessment shall be established for all relevant situations including but not limited to: vehicle
25、collision related leaks, component corrosion related leaks, component durability related leaks and component assembly related leaks. 5.1 At a minimum, the following scenarios shall be considered in the risk assessment for R-744 CO2: x Inhalation exposure to CO2 concentration above health limits due
26、to a small or large refrigerant leak into the passenger compartment x Inhalation exposure to CO2 concentration above health limits during vehicle service x Liquid or fragment projectiles resulting from high pressure system burst x Liquid or fragment projection during vehicle service x Potential star
27、tling of the vehicle driver due to rupture of the high pressure system, resulting in a possible accident Manufacturers should design systems cognizant of CO2 concentration peak level concentrations that could impact driver performance during vehicle operation, and shall measure the interior concentr
28、ations as outlined in SAE J2772. Background levels of CO2 that may exist in the vehicle need to be considered. SAE INTERNATIONAL J2773 FEB2017 Page 4 of 6 5.2 At a minimum, the following scenarios shall be considered in the risk assessment for R-1234yf HFO-1234yf: x Inhalation exposure to R-1234yf c
29、oncentration above health limits due to a small or large leak in the passenger compartment x Inhalation exposure to R-1234yf concentration above health limits during vehicle service x Ignition event associated with large leak in the passenger compartment x Ignition event due to R-1234yf release duri
30、ng vehicle service x Inhalation exposure to HF concentration above health limits AEGL2 resulting from refrigerant thermal decomposition in the event of a refrigerant release Manufacturers should design systems cognizant of the flammable properties of R-1234yf and the potential for ignition sources t
31、hat could ignite the refrigerant. 5.3 All other refrigerants considered for MAC usage shall comprehend similar scenarios and the appropriate refrigerant properties in the risk assessment. 6. NOTES 6.1 Revision Indicator A change bar (l) located in the left margin is for the convenience of the user i
32、n locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publica
33、tions, nor in documents that contain editorial changes only. PREPARED BY SAE INTERIOR CLIMATE CONTROL STANDARDS COMMITTEE SAE INTERNATIONAL J2773 FEB2017 Page 5 of 6 APPENDIX A - EXAMPLE RISK ASSESSMENT INPUTS A.1 TOXICITY INPUTS x LC50 or ALC studies in rats x Tabulae Biologicae studies x Repeated
34、dose studies x Genotoxicity in vitro studies x Ames tests x Teratogenicity in multiple species x AIHA WEEL committee TWA values x NOAEL values A.2 CARDIAC SENSITIZATION x Cardiac sensitization studies A.3 ANESTHETIC EFFECT x Studies of anesthetic effects A.4 OTHER ESCAPE-IMPAIRING EFFECTS AND PERMAN
35、ENT INJURY x Occupational Safety and Health (NIOSH) IDLH Immediately Dangerous to Life and Health limits A.5 OTHER FACTORS x Pressures during operation and service of vehicles shall be considered. x Flammability properties including those shown in the table below x Other properties available in the
36、current published MSDS sheets Table A1 - Flammability properties Upper Flammability Limit, Vol. % in air (21C, ASTM E681) Lower Flammability Limit, Vol. % in air (21C, ASTM E681) Minimum Ignition Energy, mJ at 20C and 1 atm (per IEC 79-3, 3rd ed., 1990) Autoignition Temperature, C (EC Physico/Chemic
37、al Test A15) Heat of Combustion, MJ/kg per ASHRAE Standard 34 Fundamental burning velocity, cm/s (per ISO 817) Minimum Ignition Current (per IEC 79-3, 3rded., 1990) Minimum Ignition Current Ratio (per IEC 79-3, 3rded., 1990) SAE INTERNATIONAL J2773 FEB2017 Page 6 of 6 APPENDIX B - HEALTH BASED LIMIT
38、S FOR HYDROGEN FLUORIDE (HF) B.1 AEGL: ACUTE EXPOSURE GUIDELINE LIMIT AEGLs have been developed primarily to provide guidance in situations where there can be a rare, typically accidental exposure to a particular chemical that can involve the general public. They, therefore, differ from other exposu
39、re guideline values in that they are based primarily on acute toxicology data and not sub -chronic or chronic data. The guidance therefore does not reflect the effects that could result from frequent exposure. Also, they are designed to protect the general population including the elderly and childr
40、en, groups that are generally not considered in the development of workplace exposure levels. AEGLs consist of three specific values for a chemical of interest, corresponding to increasing severity of health effects with increases in exposure time (10 min to 8 h). x AEGL-1: Exposures below this valu
41、e will result in no adverse health effects. x AEGL-2: Exposures below this value may result in mild and reversible effects, such as irritation or discomfort, but will not impair the ability to escape or result in permanent health effects. This value shall be used in assessing the risk of exposure to
42、 HF x AEGL-3: Exposures below this level are not lethal, but could result in long-term health effects. Hydrogen fluoride (HF) is a potential decomposition product for any fluorine containing refrigerant product, (R-152a, R-134a and R-1234yf). Refrigerant is not expected to come into contact with ope
43、n flames or red hot surfaces during normal usage. However, in the unlikely event that R-1234yf should come into contact with an open flame or red hot surface (possibly from an accident) there is a possibility that the refrigerant may decompose into HF. Hydrogen fluoride (HF) is a noxious and irritan
44、t gas. The odor threshold for HF varies among individuals but has been reported to be 0.02 to 0.13 ppm (NRC, 2004). Appropriate guidelines for assessing acute exposures to HF in an emergency situation include the Emergency Planning Response Guideline (EPRG) values published by the American Industria
45、l Hygiene Association (AIHA) and the Acute Exposure Guideline Limits (AEGLs) established by the U.S. National Advisory Council for AEGLs and National Research Council (NRC).1Occupational exposure values such as the U.S. Occupational Health and Safety Administrations (OSHA) Short Term Exposure Limit
46、(STEL) or the National Institutes of Occupational Health and Safety (NIOSH) shall be used. Recommended Exposure Limits (REL) are not appropriate values for consideration because these values are intended for workers who may be exposed repeatedly to these values over the course of their job tenure (i
47、.e., multiple brief exposures per work week or even per day). Such a value would not be consistent with the emergency-type situation envisioned by release and ignition of a refrigerant. The AEGL-2 values represent reasonable health-based limits for use in this risk assessment. The key concern should
48、 be to prevent situations in which the individual is unable to safety operate the vehicle or take action (e.g., stopping, opening windows) in order to avoid significant and permanent injury. AEGL-1 values, which represent a threshold for minor discomfort, would be overly restrictive for evaluating s
49、cenarios which by their very nature involve other hazards such as collision-related trauma, exposures to smoke or flames in car fires, etc. x AEGL-2 value for HF is 95 ppm for 10 min x AEGL-2 value for HF is 34 ppm for 30 min x AEGL-2 value for HF is 24 ppm for 60 min 1Provisional AEGLs are developed and proposed by the U.S. National Advisory Council for AEGLs with administrative su
