Appendix A


This Appendix contains requirements for maintenance, selection, and installation of gas-detection systems. Explanations for when gas detection is required are presented in the General Compressed Gas Systems, Flammable Gases, and Health Hazard Gases sections of this chapter.

Detection System Maintenance

General Maintenance Requirements

  • The principal investigator or gas-use supervisor is primarily responsible for the management of gas-detection system maintenance related to his or her project or operation.
  • Maintenance must at a minimum follow manufacturer’s recommendations for maintenance, including frequency of maintenance, and LBNL/PUB-3122, Maintenance Program Guidelines for Programmatic Equipment. Testing of the detection system’s ability to detect and transmit a signal to the Fire Department must follow NFPA guidelines, or must occur on at least a quarterly basis. The Facilities Department will provide technical guidance, if requested.
  • Maintenance Personnel

  • The principal investigator may assign maintenance tasks to qualified subordinates, the Facilities Department, or contractors.
  • Personnel conducting detector maintenance must be adequately trained, having detector manufacturer recommended training, or an equivalent, and be certified as “qualified” maintenance personnel.
  • Maintenance Documentation

    A formal system of documentation will be maintained for each gas detection system, and will include:

  • Manufacturer’s operation and service manuals
  • Preventive maintenance procedures, post-maintenance testing, schedules, and records of results
  • Procedures and records for verifying proper connection of detector alarms and interlocks
  • Records of all repairs, calibrations, nonroutine maintenance, and system failures
  • Names and qualifications of maintenance personnel
  • Calibration source documentation
  • A one-year summary (e.g., log) of function checks and maintenance actions performed must be visibly maintained on the detector system. Minimum summary information must include date, person’s name, and action taken.

    Detection System Selection


    Systems must be listed by Underwriters Laboratory, Factory Mutual, or Canadian Safety Association, and the California State Fire Marshall’s office, or equivalent. The Fire Department may approve unlisted equipment if listed equipment is not available or is inferior.


    Gas-detector sensitivity must be below the lowest PEL or TLV for health hazard gases and/or at or below 10–15% of the lower explosive limit (LEL) level for flammable gases.


    System hardware must include:

  • Separate relays for “warning” (low-concentration gas detection), “alarm” (high-concentration gas detection), and “trouble” (malfunction) conditions, and normally open and normally closed dry-contact-relay output capability for specified but adjustable levels of gas detection.
  • Capability system that is installed as fixed-in-place, with hard-wired and plumbed connections.
  • Control protection from direct unauthorized personnel access.
  • Detection System Installations


    Detection system installations will be designed and documented (i.e., plans and as-built drawings) by the Facilities Department. A Facilities Department licensed professional engineer and EH&S Fire Protection Engineer will approve all designs prior to contract award or installation. In addition, an EH&S Industrial Hygienist will approve all toxic and oxygen-deficiency-detection system designs.

    Sample Point Locations

    Gas-detector sample points must be placed immediately adjacent to potential leak points or in the flow path of exhausted enclosures.

    Alarm Locations

    All gas-detection systems must have:

  • Audible and visual alarms in the following locations: gas supply location, gas use or operator room, and outside the gas use room (e.g., corridor).
  • An alarm status and gas-concentration readout panel must be located outside the gas use room.
  • Local audible and visual alarms must be specific and distinct from fire alarm bells and have signs to indicate the alarm’s meaning and required personnel action.
  • Alarm Monitoring

    Gas-detection systems required by this policy must have alarm connections to the Berkeley Lab Fire Department Alarm Room, which continuously monitors alarm status. Alarm connections must be made through the building and Berkeley Lab fire alarm system, must transmit “alarm” and “trouble” signals as separate zones, and must be made in accordance with NFPA 72.

    Alarm Conditions and Actions

  • Alarm conditions must consist of “trouble,” “warning,” and “alarm.”
  • Toxic-gas “warning” and “alarm” level setpoints must normally be set at less-than-PEL/TLV and equal-to-PEL/TLV concentrations, respectively.
  • Flammable-gas warning and alarm level setpoints must normally be set at 10–15% LEL and 20% LEL, respectively.
  • Low-level “warnings” must activate local alarms and personnel response only.
  • High-level “alarms” must activate local-area evacuation, automatic gas shutdown at the gas source, and Fire Department notification.
  • Power and Control

  • The detection and alarm systems will be connected to emergency power. In the event of a power failure, the detection system must continue to operate without interruption (e.g., must have an uninterruptable power supply), or gas systems must be automatically shut down at the gas source.
  • Power connections, control switches, and adjustments that affect the system’s safety control must be protected from direct access (e.g., must be hard-wired or covered and locked).
  • Responsible Parties

    Principal Investigator/Supervisor

  • Ensures that gas users are adequately protected by verifying that appropriate detector systems are selected and installed.
  • Ensures implementation of detector maintenance and calibration in an approved manner.
  • Ensures that records of gas-detection system maintenance are maintained and archived.
  • Provides records of new or removed gas-detection systems to Maintenance.
  • Ensures that documented self-assessments of gas detection system functions and maintenance are conducted.
  • Facilities Department — Maintenance

  • Manages gas-detector maintenance services for detector users who request service. Provides service on a chargeback basis through Maintenance, outside contractors, or other means.
  • Maintains and archives records of gas-detection system maintenance for activities that are managed by Maintenance. In addition, provides maintenance status reports to the principal investigator.
  • Administers detector maintenance contracts, if requested.
  • Maintains an updated inventory of all gas detectors, and provides copies of same to EH&S.
  • Installs and maintains fire alarm systems used to monitor gas-detection systems.
  • Assists in the selection, installation, and startup of maintainable and reliable detector systems.
  • Facilities Department — Engineering

  • Assists in gas-detector system and hardware selection.
  • Develops and approves detector, alarm, and interlock system design packages.
  • Reviews and approves detection system construction, installation, and startup.
  • EH&S Industrial Hygiene Group

    Provides an EH&S coordination role in the following areas:

  • Assists in detector, alarm, and interlock-system conceptual design and selection. Approves design and installation. Witnesses acceptance tests of detection systems.
  • Specifies alarm setpoint concentrations.
  • Determines toxic-gas physiological warning property ratings.
  • Periodically audits installation and maintenance of gas detectors as one component of the EH&S Integrated Functional Appraisal Program.
  • EH&S Fire Department

  • Monitors and responds to alarms transmitted via the fire alarm system or emergency telephone number system.
  • _____________________

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