Roof Access

When work is necessary on fume hood exhaust systems, proper personal protective equipment (PPE) must be worn at all times. Personal protective equipment (PPE) is also necessary for work on, or entry into, the exhaust plenums in buildings with fume hoods where general roof access is "unrestricted." Fume hoods must be POSTED (on the sash) out of service per the procedure below anytime power will be shut down or other work is performed that impairs the normal safe operation of the hoods. It may be necessary to POST fume hoods out of service per the procedure below. If the hood is POSTED out for work on the inside of the fume hood itself (i.e plumbing, electrical, etc.), the hood surfaces must be cleaned by laboratory personnel prior to work beginning. Personal protective equipment may include respiratory protection, chemical-resistant clothing and gloves, and safety glasses or goggles. Contact Environmental Health & Safety at 540-231-3427 for assistance, if necessary.

General roof access is often necessary to perform tasks other than those involving fume hood exhaust systems. Depending on the design of the exhaust system, the potential for chemical exposure may exist for personnel on the roof. Authorized personnel only are permitted on building roofs. Refer to the Roof Access Chart to determine the roof access level - "Restricted" or "Unrestricted," and follow the guidelines below for safe and proper access. 

"Unrestricted"

Buildings with "unrestricted" roof access have strobic-like exhaust design and the potential for chemical exposure is minimal. No special precautions are necessary for chemical exposure.

"Restricted"

Buildings with "restricted" roof access do not have strobic-like exhaust design and the potential for chemical exposure requires that one of the following precautions be taken:

1. Fume hoods must be POSTED as out-of-service during roof access by the department(s).

• Personnel accessing the roof must coordinate directly with the building point(s) of contact at least three (3) working days prior to access to have fume hood(s) shut down for affected laboratories and work groups. 
• Departmental personnel must post a notice on the fume hood(s) indicating the date(s) and time(s) the hoods will be out of service (i.e. powered off, chemicals and wastes transferred to designated storage locations or cabinets outside of the hood if possible or containers properly capped and secured, hood sashes closed, and no active work going on). 
• POSTINGS must be placed on the closed sash. The number of fume hoods will be identified in parentheses for the building to help coordinate tagging hoods out of service, if necessary. Note: POSTNG a fume hood out of service does not physically prevent laboratory personnel from using the hoods. Department Management is responsible for enforcing lab compliance with all tag instructions related to the shutdown. A sample tag can be found here.
• The Departmental contact must inform the person requesting access that proper posting is complete before work may proceed at that point.
• If for any reason the scheduled work will not be performed during the requested time period, and fume hoods have already been tagged out of service, notify the Department immediately to avoid unnecessary disruption of laboratory activities. 

2. Proper respiratory protection must be used if fume hoods cannot be posted out of service on "Restricted" roofs if work is being performed directly on the chemical fume hood exhaust system, or in cases where emergency access may be necessary. Where respirators are required, the user shall use a P100/Multi-gas/vapor cartridge suitable for the type of respirator being used. This cartridge will protect the user from multiple potential exposures, such as organic vapors, chlorine, hydrogen chloride, sulfur dioxide, chlorine dioxide, hydrogen sulfide, ammonia, methylamine, formaldehyde, or hydrogen fluoride, and non-oil and oil particulates. VT personnel must comply with EHS' Respiratory Protection Program.

3. Short-term excursions onto "restricted" roofs may be approved on a case-by-case basis if it can be determined that no chemical exposure or risk exists. Contact the Chemical Hygiene Officer at 540-231-3427 for access review and approval.

Where the Roof Access Chart indicates a potential biological hazard, approval from the department is required prior to accessing the building roof. Coordination of work and fume hood shutdowns may be necessary.

Where the Roof Access Chart indicates a potential radio frequency hazard, coordination with the radio tower owner to be powered it down prior to access may be necessary. Contact the appropriate radio station owner for coordination and access.

Where emergency notification systems are present on a roof, severe noise hazards will be present if the siren/emergency notification system is activated during roof access. If relay "clicks" are heard, indicating activation, leave the roof area immediately.

Fall hazard situations exist on all building roofs.  Some may have sufficient fall hazard protection where no special requirements must be followed. Others may require the use of fall protection systems. Follow the information provided for the access code below. If no code is available, contact EHS at 231-2341 for review.

• Unknown: Access to this roof has not been reviewed. Please contact Facilities and/or EHS for assistance, if needed.
• 1 - No Access: Access is not permitted on this roof until a fall protection system has been implemented and/or corrected.
  • 1A: No access permitted on this roof at this time. Contact EHS for review and recommendations, if necessary.
  • 1B: Access from aerial lift or scaffolding only. 
• 2 - Guardrails/Parapet Wall (of sufficient height) Provided: Appropriate parapet walls and/or guardrail system is in place. Stay within the confined area.
• 3 - Warning System Required:
  • 3A: Construction Work, a warning line system that meets OSHA requirements for construction must be implemented. See 29 CFR 1926.502(f) for more information.
  • 3B: General Industry Application (e.g. maintenance), a designated area must be established.
• 4 - Personal Fall Arrest System Required: Only trained personnel, wearing appropriate an appropriate PFAS, attached to an approved anchor point may access this roof, or be within 6 feet of the edge of the roof. Note: Designated anchor points on campus are for personnel attachment only. Equipment must be attached to some other structure.
  • 4A: Permanent anchor points have been installed for use.
  • 4B: Mobile anchor points are available for use. Only trained personnel may use this system. Mobile anchor points must be used in accordance with manufacturer instructions at all times.
  • 4C: Temporary anchor points must be installed. Contact EHS for review and recommendations.
  • 4D: Horizontal Life Line provided.
  • 4E: Travel Restraint System provided.
• 5 - Safety Monitor System Option: If no other means of protection are feasible and certain conditions are met, a safety monitor system may be used.