ES&H Manual



6550 Appendix T3

Emergency Response to an

Uncontrolled Cryogen Release



1.0             Purpose

This appendix describes how to recognize an uncontrolled cryogen release and the appropriate response procedure steps to follow.

2.0             Scope

The process steps for this procedure are performed in coordination with ES&H Manual Chapter 6550 Cryogenic Safety Program.


Emergencies related to oxygen deficiency hazards are discussed in ES&H Manual Chapter 6540 Appendix T1 ODH Emergency Procedures.


Emergency responses for situations are discussed in ES&H Manual Chapter 3510 Emergency Management Plan.

3.0             Responsibilities

NOTE:           Management authority may be delegated to a task qualified Jefferson Lab employee at the discretion of the responsible manager.

3.1              Anyone at Jefferson Lab (not trained in cryogenic emergency response)

·         Respond to an uncontrolled cryogen release per this appendix.

3.2              Supervisor/Subcontracting Officer’s Technical Representative (SOTR)/Sponsor

·         Report an event or near-miss to the ES&H Reporting Officer in accordance with ES&H Manual Chapter 5200 Event Investigation and Causal Analysis Process.

4.0             Process Steps

Unless otherwise stated, anyone at Jefferson Lab may perform the process steps outlined below.

4.1              Uncontrolled Cryogen Release

Warning signs of an uncontrolled cryogen release include:

·         Severe Temperature Drop in Area – A cryogen release can drop temperatures to -244° F (120 K) within a 10-foot radius in a few seconds.

·         Vapor Plume – An uncontrolled release causes a visible water-vapor plume until the gas warms. 

·         Rushing Gas Sound – A high-pressure cryogen release can produce a hissing or whooshing sound associated with rushing gas.


Step 1:            Don and Activate an Emergency Escape Pack (EEP) if available.


Step 2:            Evacuate the area. (If an outdoor release, evacuate 100 meters upwind of a plume. If an indoor release, evacuate out of the building and remain upwind.)

·         Stay away from vapor plumes.

o   If you see a vapor plume, use an alternate route.

o   If you find yourself in a vapor plume and do not have an EEP, hold your breath until you are out of the plume.

·         If a worker is injured or unconscious, do not attempt to rescue them. Only offsite emergency responders are trained, qualified and authorized to perform rescue operations.


Step 3:            Muster Point

·         Call 911 and Occupational Medicine (x7539) immediately if:

o   Workers are missing or injured

o   You are unsure of a person’s location or condition


Step 4:            Notifications (made from a safe location)

·         Security (x5822)

·         Occupational Medicine (x7539)

·         Crew Chief (x7045)

·         Supervisor, SOTR, or Sponsor


Figure 1: Flowchart for Emergency Response to Uncontrolled Cryogen Release


5.0             Revision Summary


Periodic Review – 06/28/19 – No changes per TPOC

Revision 1.3 – 06/30/16 – Clarified Emergency Response Expectations

Revision 1.2 – 03/19/15 – Updated Technical POC from Dana Arenius to Jonathan Creel

Revision 1.1 – 10/30/14 – Clarified evacuation instructions for uncontrolled cryogen release

Revision 1.0 – 01/17/12 – Updated to reflect current laboratory operations








ES&H Division

Jonathan Creel




This document is controlled as an on line file.  It may be printed but the print copy is not a controlled document.  It is the user’s responsibility to ensure that the document is the same revision as the current on line file.  This copy was printed on 6/28/2019.