The first standards addressing portable electrical detectors for toxic gases and vapors were developed in the European Union by a Joint Working Group of the European Committee for Standardization (CEN) and the European Committee for Electrotechnical Standardization (CENELEC). This working group produced a four-part standard: EN 45544 (since revised in 2016), . This standard incorporated performance uncertainty requirements from another CEN standard, EN482, Workplace Exposure – General Requirements for the Performance of Procedures for the Measurement of Chemical Agents. However, once the CEN/CENELEC Joint Working Group had done its job, it became clear that other national standards existed around the world. These standards included:

• ANSI/ISA-92.00.01-2010,
  Performance Requirements for Toxic Gas Detectors
  and ANSI/ISA 92.00.02-2013,
  Installation, Operation, and Maintenance of Toxic Gas-Detection Instruments
  , developed by the International Society for Automation and published as American National Standards
  
• UL 2075,
  Gas and Vapor Detectors and Sensors

  from Underwriters Laboratories
  (now UL, LLC)
  
• CAN/ULC-S588,
  Standard for Gas and Vapour Detectors and Sensors, Including Accessories
  (a Canadian standard)
  
• AS/NZS 4641:2007,
  Electrical Apparatus for the Detection of Oxygen and Other Gases and Vapours at Toxic Levels – General Requirements and Test Methods
  (a standard in Australia/New Zealand)
  
• ASTM E2885,
  Standard Specification for Handheld Point Chemical Vapor Detectors (HPCVD) for Homeland Security Application
  , developed by ASTM International
  

In addition, U.S. NIOSH has published a Technical Report 2012-162: (as well as an addendum, ). This technical report also provides performance tests. The “precision and accuracy” concept used by NIOSH is generally equivalent to the “expanded” uncertainty used in EN482.  International cooperation on standards is important for creating a level playing field in commerce, to allow manufacturing and sales to be unencumbered by the necessity of meeting proliferating national and regional standards. At the time the EN standards were undergoing revision and the NIOSH technical report was published, I recommended the revival of a Working Group on Gases within the International Organization for Standardization. This Working Group existed within the Workplace Atmospheres subcommittee of ISO’s Technical Committee 146 on Air Quality. Thanks to existing agreements between ISO, CEN, and IEC, it was relatively simple to replace a regional CEN/CENELEC Joint Working Group with an international equivalent, Joint Working Group 45, which drew members from both ISO TC 146 SC 2 WG3 and IEC TC 31 MT 60079-29. Since the greater expertise lay within the IEC body, it naturally became the lead, with the convenor (a position similar to that of chair) and secretary being drawn from IEC.

The official roster of JWG 45 includes 27 participants from IEC representing 13 countries and 20 participants from ISO representing seven countries. (These numbers include individuals who belong to both organizations, and some who are not active.) Meetings have been held in the U.S., Canada, Germany, Russia, Belarus, Croatia, and Australia, generally in connection with the parent committee’s meetings (IEC TC 31). Unfortunately, there has been no ISO participation in meetings outside North America and Europe. The last meeting was held at AIHA headquarters in Falls Church, Va., in October, while the next meeting will be in October or November 2019. Two standards are at advanced ballot stages under the JWG 45: IEC/ISO 62990, , and IEC/ISO 62990, . These standards classify two types of detector:

• Type SM (safety monitoring) “general gas detection” equipment: for general gas detection applications (for example, safety warning, leak detection), where the performance requirements are focused on alarm signaling and the measuring range is defined by the manufacturer. 
  
• Type HM (health monitoring) “occupational exposure” equipment: for occupational exposure measurement, where the performance requirements are focused on the uncertainty of measurement of gas concentrations related to occupational exposure limit values.
  

Part 1 of IEC/ISO 62990 is ready for its Final Draft International Standard ballot. No technical changes are allowed at this time: member countries are required to vote affirmative, negative, or abstain, a plurality of affirmatives will carry the day, and, if approved, the standard will be published until a new work item to modify, withdraw, or replace is undertaken. Part 2 will go out for its Draft International Standard ballot, and comments from this ballot will be addressed at the next meeting. The JWG includes two commercial test laboratories (Factories Mutual in Rhode Island and DEKRA EXAM in Bochum, Germany) that assisted with developing the procedures and designing the equipment for testing the detectors. It was very important that the tests in these standards not be so exacting that no equipment could ever pass them, nor so expensive as to effectively prevent their adoption. When final, these new standards will help inform the revision of AIHA’s Field Use of Direct Reading Instruments Body of Knowledge and the Field Use of Direct Reading Instruments certificate program. How can these standards be used by our IH community? As with all standards, the end-users must be aware of them and ask vendors or other parties to make use of them. Of course, regulators could compel the use of performance standards through regulation. After all, if a ladder must meet federal requirements, shouldn’t a toxic gas detector?  A subtler but equally effective path is for a customer to include a requirement for testing and certification as part of the sales contract. To help customers make knowledgeable purchasing decisions, AIHA’s Real-Time Detection Systems Committee has spent much effort developing Standardized Equipment Specification Sheet forms. The Committee created two SESS forms: one for instruments, and one for sensors. Each SESS form includes performance metrics, which are aligned with the NIOSH Technical Report tests, and which have their equivalents in the IEC/ISO standard tests. SESS forms are intended to be completed by instrument manufacturers at the request of anyone interested in purchasing a meter. Manufacturers could slot the results of their performance testing right into the SESS and could indicate the standards against which any piece of equipment was tested.  The SESS forms (version 2.0) can be downloaded from the Real-Time Detection Systems Committee . Also available is a SESS manual that explains in detail how to use the forms. (For more information, read Patrick Owens’ article “” in the June/July 2017 issue of .) In addition to the use of sensors in workplace air monitoring, there has been substantial promotion of sensors for use in ambient air through “citizen science” projects. Sensors for typical ambient air pollutants such as particulate matter, carbon monoxide, and ozone are being produced cheaply, and miniature, wearable devices containing multiple sensors are now available. The National Institute for Environmental Health Sciences and EPA have a considerable interest in these instruments, especially as tools to be used in meeting the goals for Exposure Science in the 21st Century, an inter-agency effort to identify efficiencies and opportunities to collaborate in exposure science. One difference between instruments for occupational use and those for environmental applications is that guidance on interpreting the output of environmental sensors may not be readily available. As these sensors continue to proliferate, questions regarding the significance of high readings will likely be fielded by local environmental and health departments, whose staff probably have limited technical expertise. The provision of training and educational resources for these individuals will be critical.  Performance standards are also necessary for confirming the accuracy and reliability of these products. In August 2018, ASTM International initiated standard WK64899, , and EPA is likely to participate. An ASTM subcommittee on Indoor Air Quality also has a new work item, WK62732, . In addition, Newport Partners, LLC, alongside researchers at the South Coast Air Quality Management District of California, is involved in new work items to characterize monitors for specific issues, such as carbon dioxide and PM2.5 indoor air sensors, for submission as ASTM standards. It is almost certain that similar initiatives exist in Europe. Is this “déjà vu all over again”? Is it time for a new Joint Working Group?   Send feedback to The Synergist.

International cooperation on standards is important for creating a level playing field in commerce, to allow manufacturing and sales to be unencumbered by the necessity of meeting proliferating national and regional standards.