# Occupational Safety and Health Administration — Hazardous Materials Safety Interpretation

- **operation:** document
- **citation:** 02-0339
- **title:** Occupational Safety and Health Administration — Hazardous Materials Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 2002-05-21
- **effective on:** Not available
- **summary:** 02-0339 response to Occupational Safety and Health Administration concerning 171.7.
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-interpretation-02-0339.json
- **markdown:** https://regulus.evalyn.ai/document/phmsa-interpretation-02-0339.md
- **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-02-0339
- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2002/020339.pdf
**body:**

<<<PAGE 1>>>

•
•
Memorandum
US Deportment
of Transponation
Research and
Spedal Programs
Administration
Dale
MAY 2 1 2002
Reply to Arn of.
Subject
INFORMATION:: Response to Request for Review
Delmer F. Billings, Chief
From
Standards Development, OHMS
To
Mike Marshall
Occupational Safety and Health Administration
Office of General Industry Compliance Assistance
This is iin reference to your facsimile dated February 7, 2002 and our telephone conversation,
concerning the storage of Compressed Natural Gas (CNG) in DOT 3AA cylinders. Specifically, you
asked if a cylinder made in conformance with a specification listed in the table in § 173.34(e)(13) and
used exclusively in CNG service, instead of a periodic hydrostatic retest, be given a complete external
visual inspection at the time periodic retest becomes due. In addition, you requested our office to
review your draft of interpretation.
We suggest that the following language and/or corrections be used in your response:
Reply to Question number li
The Department of Labor's Occupational Safety and Health Administration (OSHA) workplace health
and safety requirements apply to the storage of CNG in DOT 3 AA specification cylinders. In addition,
your cylinders must conform to DOT regulatory requirements applicable to the maintenance and
requalification of DOT 3AA cylinders. The Hazardous Materials Regulations (HMR; 49 CFR Parts
171 - 180) apply to the transportation of hazardous materials in commerce, including packaging
authorized for such transportation. Packaging manufactured in accordance with HMR requirements
must be marked to indicate conformance with the specific requirements applicable to the packaging.
The OSHA regulations incorporate the HMR by reference; thus, the OSHA standards also require
DOT specification 3AA cylinders used for storage to be maintained and requalified in accordance with
the HMR requirements. Further, cylinders used to transport hazardous materials in commerce are
subject to HIMR and may not be offered or transported unless they are maintained and requalified in
accordance with the HMR.

<<<PAGE 2>>>

* OSHA/DOT Requirements
As your facsimile notes, the visual inspection requirements in §173.34(e)(10) of the HMR are for
cylinders used exclusively for materials specifically listed. However, the provision allowing performance
of a visual inspection instead of a hydrostatic test applies only to cylinders used exclusively for the
materials specifically listed in the table is contained in §173.34(e)(13). The material, CNG you
identified is not listed in the table. Therefore, cylinders used exclusively for CNG service does not
qualify for the five-year complete external visual inspection in §173.34(e)(13). Thus, the hydrostatic test
as specified in the§173.34(e) table must be used.
With regard to your reference to the Compressed Gas Association (CGA) pamphlets, C-6 and C-8,
Section 173.34(e)(3) of the HMR prescribes that a DOT specification cylinder must be visually
inspected, internally and externally, in accordance with CGA Pamphlets C-6, C6.1, C 6.2, as
applicable. CGA pamphlet C-8 applies to requalification of 3HT specification cylinders thus would
not be applicable to DOT 3AA specification cylinders, as noted in your letter. In addition, the CGA
pamphlets are specifically listed in the §171.7 table which sets forth materials (e.g. CGA pamphlets)
incorporated by reference into the HMR. Therefore, as prescribed under 173.34(e)(2)(v)(C), the
pamphlet maintained must be the edition incorporated by reference in §171.7.
I hope this information is helpful. If you have further questions, please do not hesitate to contact this
office
#

<<<PAGE 3>>>

02/27/02
WED 11:28 FAX 202 693 1628
OSHA/DER/GICA
B00i-
FAX MESSAGE
OCCUPATIONAL SAFETY and HEALTH ADMINISTRATION
OFFICE of GENERAL INDUSTRY COMPLIANCE ASSISTANCE *
200 CONSTITUTION AVENUE, N.W., N-3107
WASHINGTON, D.C. 20210
PHONE: (202) 693-1850
FAX: (202) 693-1628
Please deliver the following document to:
NAME: Sandra Webb
OFFICE:
DOT - RIPA
=
PHONE: 31010-3072
FAX:
366-3012
Total number of pages (including this page): 5
FROM:
Mike Marshall.
PHONE:
OSHA
comments: Sawdra: Per your vorcemeil. Have is
my draft on
viles, Lex an. Plane take a lost at my enterp of your
me too if these ENd cylinters one reformed
to be hudiod And have visuals internal enterval espections.
Also whather I' off buse on ary other siles.
Thank
PLEASE CALL IMMEDIATELY IF THIS FAX IS INCOMPLETE OR ILLEGIBLE.
Mike

<<<PAGE 4>>>

02/27/02 NED 11:30 FAX 202 693 1628
OSEA/DCP/GICA
- -
D00z
Original Draft -CNG Fueling Station 1910.101 D-113-1
MILM January 25, 2002
Initials
Dase
Last Name
Marshall
Wilkins
Probert
Office Symbol o
Buchanan
Pairfes
GICA
GICA
Slattery
DCP
Vassale
GICA
Sothiem
DCP
DSSP
SOL
DCP
OSCAL MARSHALL\1/25/021N31021693-21791D #113
pilmarshalls on "Daffy" (:)Iwplwp61 lundocs gicalinterps|CNG Fueling Station 1910.101D-113-1
(Vassalo) Elveston (HSAOJALL RASIOTI (Hovicz) HR/EPA-CEPPO (C. Mathiessen)ICHROMSUBJECTDO
:FAIRFANGALASSABUCHANANARSHALLI ALL SAA SIEGFRIEDI WILKENSIS STANDARDSISOL
Submit to OCIS & DCP Homepaze
SEE WHITE COPY for SUPPORTING REFERENCES
DCP/GICAMLM/D-113
Mr. Hank Seiff, P.E.
Director of Technology
The Natural Gas Vehicle Coalition
400 North Capitol Street, NW
Washington, DC 20001
Dear Mr. Seiff.:
Thank you for your November 9, 2001-Ietter to the Occupational Safety and Health
Administration's (OSHA's) Directorate of Compliance Programs (DCP). You have questions
regarding OSHA's Compressed Gasses (General Requirements) Standard, $1910.101. Please be
aware that this response may not be applicable to any question or situation not delineated within.
application of a latter version of a document which is incorporatod by reference into OSHA
Scenario: U.S. Department of Transportation (DOT) 3 AA cylinders are used for storage of bigh
presure gas at some CNG vehicular refueling stations.
Question #1: Does OSHA have any requirements or guidelines for station operators on the
inspection and maintenance of these fuel storage cylinders?
Reply: First, OSHA would have jurisdiction over the situation you describe. The DOT 3AA
to enforce its regulations over the storage of CNG in cylinders at the described locations.

<<<PAGE 5>>>

02/27/02 TED 11:30 FAI 202 893 1628
OSHA/DCP/GICA
฿003
1 7
popeline
Consequently, there is no pre-emption of OSHA authority and OSHA would enforce its
•workplace health and safety regulations over the situation you describe.
7
OSHA/DOT Requirements
While OSHA has not published any guidelines on the situation you describe, we do have
regulations related to the inspoction and maintenance of compressed gas cylinders, which include
CNG cylinders. OSHA has incorporated by reference DOT Hazadous Materials Regulations, 49
CFR Parts 171-179 (ammended January 1, 1970). Part of OSHA regulation §1910.101(a)'
requires station operators/employers to determine that compressod gas cylinders under their
control are in a safe condition to the extent that the cylinders' mechanical integrity can be
determinod by visual inspection. OSHA and DOT recognize that based on the service of the
cylinder, i.e., material, pressure, etc. a visual inspection alone may be insufficient to determine the
mechanical integrity of a compressed gas cylinder. Therefore, an employer may not be able to
adaquately determine the condition of their cylinder(s) based merely on a visual inspection.
Therefore, OSHA and DOT require visual and other inspections as prescribed in the refcrenced
DOT regulations. DOT has a regulation, 49 CFR 173.34, Qualification, Maintenance and Use of
Cylinders (a copy of this section of the 1970 incorporated standard is attached), which is
applicable to your question. In particular, 49 CFR §173.34(e), Periodic relesting and reinspeciion
of cylinders, requires periodic retesting of DOT 3AA cylinders every 5 years. This requirement
would be applicable to DOT 3AA cylinders containing CNG. Further, 49 CFR §173.34(c)(1)°
specifies criteria to be included in a periodic relest and also requires a visual internal and external
examination.
As stated in the previous paragraph, in addition to byrostatic retesting, 49 CFR §173.34(e)(1)
requires a visual internal and external examination of DOT cylinders. While the particular DOT
1970 standard does not specify the criteria for the interal and external examinations, the current
DOT standard, 49 CFR 173.34(e) 3)', Visual Inspection, (see the website
http://63.141.231.97/cgi-bin/om_isapi.dil/infobase=petdordsoftpagc=Doc_Frame_842 for the
current version of this regulation) does specify criteria for these inspections. Based on the 1970
DOT incorporated standard requirement to conduct interpal and external visual inspections,
29 CFR 1910.101(a) Inspection of compressed gas cylinders. Each employer shall devermine
be derermined by visual inspection. Visual and other inspecsions shall be conducted as prescribed
that compressed gas cylinders under his control are in a sofe condition to she extens that this can
179 and 14 CFR part 103). Where those regulasions are nos applicable, visual and other
in the Hazardous Materials Regulations of the Departmens of Transportation (19 CFR parts 171-
1968 and C-8-1962, which is incorporaled by reference as spectfied in Sea. 1910.6.
inspections shall be conducted in accordance with Compressed Gas Assoclation Pamphless C-6
2
49 CFR 173.34(eX(I) This periodie reless muss include a visual internal and external
apparatus of suilable form for the delermination of the expansion of the cylinder....
examinatioon logether with a test by interior hydrostatic pressure in a waler jacket or other
49 CFR 173.34(eX3) Visual Inspection. Exceps as otherwise provided in this section, each time a
cylinder is relessed, it must be visually inspecied, insernally and exserally, in accordance with
rejected or condemned according to the criteria in the applicable CGA pamphleh..
CGA Pamphless C-6, C-6.I, C-6.2, or C-6.3, as applicable. The cylinder must be approved.

<<<PAGE 6>>>

02/27/02 WED 11:30 FAX 202 693 1628
OSHA/DCP/GICA
21001
• OSHA requires employers in this case to conduct these inspections as prescribed by established
inspection criteria required by the current DOT standard 49 CFR 173.34(e)(3).
The OSHA incorporated standard, 49 CFR $173.34(e)(10) is not applicable to CNG cylinders la
his case because your CNG cylinders do not meet the listed service criteria ("...listed in the tabl
below and used exclusively in the service (emphasis addod] Indicated.."). This table only lists the
used exclussively for services of liquified petroleum gas, anhydrous ammonia, fluorinated
service materials.
hydrocarbons, butadiene, and liquified hydrocarbon gas - CNG is not one of these specified
Process Safety Management SVD Requirements
OSHA has another standard which may apply to the the inspection and maintenance of the subject
cylinders. OSHA's PSM standard, 29 CFR 1910.119 would apply to the situation you describe -
the storage and bandling of flammable gases (c.g. CNG) when an amount of flammable gas exist
in a process equal to or greater than 10,000 pounds [threshold quantity (TQ) for flammable gas].
cylinders are not interconnected but are in close proximity/co-located, their amounts are
the release of the contents of the non-interconnected cylinders.
aggregated if it is determined by the employer that an event such as a fire or explosion could cause
When a PSM-covered process does exist and none of the exemptions apply (i.e. bydrocarbon
fuels exemption, 29 CFR 1910.119(a)(1)(ii)(A), retail facilities exemption 29 CFR
1910.119(a)(2)(i), etc.), OSHA's PSM standard, 29 CFR 1910.119(), Mechanical Integrity,
specifically applies to the inspection, testing and maintenance of these cylinders. This particular
standard among other requirements, requires employers to conduct inspections and testing on
PSM-covered equipment pes recognized and generally accepted good engineering practices
(RAGAGEP) - 1910.1190)(4)(ii)*. PSM is a performance oriented standard and therefore, OSHA
does not specify the RAGAGEP employers utilize for their workplace application. PSM is a safety
management standard. The standard requires employers to specify which codes and standards they
employ (1910.119(d)(3)()(F), including RAGAGEP applications for PSM-covered inspections,
testing, and maintenance. After the employer specifies which standard they utilize for the
inspection of their cylinders, they are required to implement the provisions of the RAGAGER.
With respect to compressed gas cylinder inspection and testing, OSHAPSM does not specify or
benchmark the DOT Hazardous Materials Regulations as the only RAGAGEP. Based on input
from stakeholders, OSHA stated in the PSM final rule (see F.R., Volume 57, No. 36, pg 6390)
that it did not intend to incorporate by reference into PSM all the codes and standards published
by consensus groups. Therefore, in evaluating whether an employers engineering practices with
respect to compressed gas cylinder inspection and testing complies with PSM, OSHA would
consider among other factors, whether the employer meets the requirements of the current DOT
49 CFR 173.34, Qualification, Maintenance and Use of Cylinders regulations.
accepled good enginecring proctices.
1910.119GX4)(ii) Inspecsion and lessing procedures shall follow recognized and generally

<<<PAGE 7>>>

02/27/02 NED 11:31 FAX 202 693 1628
OSHA/DCP/GICA
B005
The PSM standard is a performance-oriented standard. When not specified, the employer has
flexibility in complying with the requirements of PSM, including recognized and generally
accepted good engineering practices.
The previous discussion has focused on employer requirements under PSM for the inspection,
testing and maintenance of DOT cylinders. Please note, when these cylinders are in a PSM-
covered process, the employer must comply with all elements of PSM.
Question #2: What is OSHA's position on whether an employer may follow latter versions of the
Compressed Gas Associations (CGA) pamphlets?
Response: The Last sentence in 29 CPR 1910.101(a) specifies thai visual and o
hall be conducted in accordance with CGA Pamphlets C-61968 and C-8-19
ctions
opening statement in this same sentence states, "Where those regulations are n
ver, the
In your case, DOT regualtions are applicable, therefore, this third sentence in 19. urune) is not
ble....".
applicable to you. As noted in the Response to the above question, CGA phamphlets are specified
in DOT's current regulation 49 CFR 134(e)(3) for the visual inspection of cylinders. In this case,
OSHA would require compliance with the current DOT regulation which spocifies latter versions
of the CGA pamphlets for establishing inspection criteria for the visual inspection of compressed
gas cylinders.
Thank you for your interest in occupational safety and health. We hope you find this information
helpful. Please be aware that the enforcement guidance contained in this response represents the
views of OSHA at the time the letter was written based on the facts of an individual case,
question, or scenario and is subject to periodic review and clarification, amplification, or
correction. It could also be affected by subsequent rulemaking; past interpretations may no longer
be applicable. In the future, should you wish to verify that the guidance provided herein remains
current, you may consult OSHA's website at http://www.osha.gov. If you have any furthes
questions, please feel free to contact the Office of General Industry Compliance Assistance at
(202) 693-1850.
Sincerely,
Richard E. Fairfax, Director
Directorate of Compliance Programs Assistance
Supperting References:
OSHA Standards
1. 1910.101(a)
- **truncated:** false
- **body characters:** 15695
