ES&H Manual



6540 Appendix T1

Oxygen Deficiency Hazard (ODH) Safety Review



Jefferson Lab has determined that working within an ODH area that has not been subjected to a Safety Review or Risk Assessment carries an unmitigated Risk Code >2. An ODH area that has been reviewed and identified control measures have been instituted is considered mitigated to a RC <2. It does not require an OSP. An Operational Safety Procedure (OSP) is required when any work is considered to be a Risk Code >2 in accordance with ES&H Manual Chapter 3210 Work Planning, Control, and Authorization Process.


1.0             Purpose


An Oxygen Deficiency Hazard (ODH) Safety Review is performed when gas is proposed, switched, or discovered in a process or an area; or as requested in accordance with ES&H Manual Chapter 3210 Work Planning, Control, and Authorization Process. If the system involved is complex and/or where experience demonstrates an ODH Risk Assessment WILL be required, an ODH Safety Review Form need not be completed. Relevant factors include, but are not limited to:


·         Volume of the area

·         Potential volume of the gas

·         Work to be performed in the area

·         Engineering controls currently in place

·         Required administrative controls

·         Existing ODH sources or installations


This appendix provides instructions on how to complete an ODH Safety Review Form so an accurate determination of risk can be made and appropriate mitigation can be implemented.


2.0             Scope


The ODH Safety Review Form is to be completed for any area before an ODH is introduced, or when it is recognized. This includes, but is not limited to, fixed sources and permanently installed equipment. The ODH Safety Review Form is also used to assist in identifying areas that have the potential to become oxygen deficient. If the potential ODH is located outside, this ODH Safety Review procedure is not appropriate. For these cases, the individual is directed to ES&H Manual Chapter 6540 T4 Oxygen Deficiency Hazard (ODH) Risk Assessment for guidance.


The process steps for this procedure are performed in coordination with ES&H Manual Chapter 6540 Oxygen Deficiency Hazard Control Program.


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

·         Complete an ODH Safety Review Form prior to introducing an ODH, prior to alteration of a system or area that might produce an ODH, when an ODH area is recognized, or as requested by a cognizant individual.


3.2              ODH Safety Reviewer

·         Review ODH Safety Review Form conclusions and, if acceptable, approve the completed form.

·         Submit a request for a Facility Design Review or ODH Risk Assessment as appropriate.

·         Distribute/File final approved ODH Safety Review Form to affected area, Document Owner and ES&H Document Control

·         Verify that ODH equipment safeguards, inventory requirements, posting, and labeling, are in-place prior to introduction of the ODH.

·         Coordinate review of documentation every three years if ODH is present.

·         Qualifications include:

o   Certified Industrial Hygienist

o   Approved by the ES&H Division Head


3.3              ODH Analysis Authority

·         Provide assistance to the ODH Safety Review Form author and the ODH Safety Reviewer as required.

·         Perform a review of ODH documentation every three years if an ODH is present.

·         Qualifications include:

o   Demonstrated ability to analyze and mitigate oxygen deficiency hazards within laboratory user systems. 

o   Maintain appropriate training SAF103 Oxygen Deficiency Hazard   

o   Technical proficiencies and knowledge of: 

§  ODH evaluations, calculations, design/implementation of control measures 

§  common compressed and liquefied gases, mixed gas properties 

§  ODH propagation calculations 

§  29 CFR 1910.146 Permit Required Confined Spaces

§  Pressurized gas mechanical systems with their associated failure modes analysis. 

o   One of the following:

§  Completion of an engineering or physics degree, requiring four or more years of full time study, plus a minimum of five years experience relating to the technical requirements listed above.

§  Professional Engineering registration, recognized by the local jurisdiction, plus experience in systems relating to ODH classification, mitigation, evaluation, and their properties.


4.0             ODH Safety Review               


4.1              ODH Description and Basic O2 Calculation: Using the online ODH Safety Review Form, fill in all information requested.


Step 1:            Introduction

·         Task Title: Brief description of work.

·         Location: Specify building, room, or area and contiguous areas and relative position within the building or larger area.

·         Effective Date: Date when the ODH will be introduced (not necessarily the date the form is approved).

·         Expiration Date: Date by which the area must be re-assessed or hazard will no longer apply (not to exceed three years).

·         Document /Division/Department Owner: Print name of person responsible for the work, their division/department.


Step 2:            Hazard Information

·         Gas(es) to be Introduced: List the name and source concentration of the gas(es). Denote any additional hazard issues that may be of concern.

·         Denote Hazard Category (See ES&H Manual Chapter 6150 Compressed Gases)

·         Denote if gas is self-contained (In a Dewar or similar?)

·         Attach copies of any existing “Oxygen Deficiency Hazard Risk Assessments” for the building and any additional supporting documents/calculations.


Step 3:            Building or Room Volume

See Facilities Management and Logistics “List of Facilities – Online Facilities Database” for square footage and Primary Custodian contact information. Consult with the Primary Custodian for height, usable area and ventilation capacities.


Step 4:            Basic %O2 Calculation

Depending on the location of your source, complete the appropriate calculation:




Source is located inside the proposed ODH area


21(VR – VG)



Source is located OUTSIDE the proposed ODH area *



 (Q + VR/t) *


VR = the total volume of the room in cubic feet

VG = the volume of gas at room temperature and pressure in cubic feet

t = time in hours(s)

Q = Volumetric flow rate of gas into room at room temperature and pressure in cubic feet per hour  (Contact Engineering if you require assistance)

* Assuming one fresh air change per hour (ACH).  If more than one ACH is needed additional review may be required.


4.2              Designate ODH Classification 0 or Perform ODH Risk Assessment: With the calculated %O2 from Step 4, use the following table to either complete the ODH Safety Review Form or revert to the procedures identified in ES&H Manual Chapter 6540 T4 Oxygen Deficiency Hazard (ODH) Risk Assessment


If Resulting % Oxygen is:

Document Owner shall:


1. Input ODH Classification “0” below

2. Obtain approvals per Department Procedures

3. Submit completed form to ODH Safety Reviewer.

18 - 19.5

1. Submit preliminary form to ODH Safety Reviewer.

2. Document Owner and ODH Safety Reviewer identify special mitigations

    that make area ODH Classification 0. Alternatively, ODH Safety

    Reviewer may request an ODH Risk Assessment.

3. Input ODH Classification “0” below

4. Obtain approvals per Department Procedures

5. Resubmit completed form to ODH Safety Reviewer for two ODH Safety

    Reviewer signatures.


Send information to ODH Analysis Authority for an ODH Risk Assessment according to ES&H Manual Chapter 6540 T4 Oxygen Deficiency Hazard (ODH) Risk Assessment. Form is no longer valid or required.

4.3              Final Submittal (does not apply to ODH Classification >0)

Step 1:            Document Owner and/or ODH Analysis Authority submit the completed online ODH Safety Review Form and relevant attachments to ODH Safety Reviewer for approval.


Step 2:            ODH Safety Reviewer reviews the completed form and:

§  Verifies ODH Classification 0

§  Provides approval signature (a second ODH Safety Reviewer signature is required for 18-19.5% O2)

§  Posts the ODH Classification signage

4.4              Distribution:   

Upon final approval, the ODH Safety Reviewer makes the following distributions:

·         Copies to: affected area, Document Owner and ES&H Document Control.

4.5              Review document every three years if ODH is still present (coordinated by ODH Safety Reviewer, performed by Document Owner) Distribution:   


5.0             ODH Safety Review Flowchart


6.0             Revision Summary


Revision 1.2 – 07/19/18 – Periodic Review; updated Step 4 Preliminary ODH calculation for outside sources and the ODH Safety Review Flowchart

Revision 1.1 – 06/22/16 – Updated TPOC from D.Owen to J.Williams

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











ES&H Division

Jennifer Williams





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 3/24/2020.