LP-Gas Odorization and Testing: Applicability, Methods and Records
Updated: Aug 3
LP-Gas includes propane, propylene, butanes and butylenes or mixtures composed predominantly of those hydrocarbons. It is not another name for natural gas. An odorization and testing plan should start with the product, facility, transportation mode, pipeline status, end use and jurisdiction.
The applicable rule can differ for workplace LP-Gas systems, LP-Gas offered for transportation, and petroleum-gas pipeline systems. One generic testing frequency, instrument specification or record-retention period should not be presented as universal.
Burgess Pipeline Services provides operational support and documentation, not legal advice.
Distinguish the Product and System
Document the operating boundary before selecting a testing method:
Product or blend and supplier
Container, cargo tank, portable tank, storage plant or pipeline system
Facility owner and responsible operator
Transportation, storage, distribution or end-use scope
Gas source and transfer points
Odorant or supplier documentation
Applicable federal, state and local requirements
Responsible person for applicability and acceptance decisions
OSHA's 29 CFR 1910.110 defines LP-Gas separately from natural gas and addresses storage and handling of liquefied petroleum gases. Where that standard applies, it requires effective odorization by an approved agent so the gas has a distinct odor at a concentration in air of not more than one-fifth of the lower flammability limit, subject to stated exceptions.
Do not apply natural-gas terminology, odorant blends or procedures automatically to an LP-Gas system.
Identify the Governing Odorization Basis
The odorization basis should be tied to the actual activity and applicable rule.
For LP-Gas in cargo tanks and portable tanks, 49 CFR 173.315(b) addresses odorization for transportation. It states that one pound of ethyl mercaptan per 10,000 gallons of LP-Gas is considered sufficient for that paragraph, while allowing another odorant when enough is used to meet the requirement. It also contains exceptions when odorization would be harmful in use or further processing, or would serve no useful warning purpose.
OSHA 1910.110 contains its own workplace LP-Gas provisions. NFPA 58 is the Liquefied Petroleum Gas Code, but the edition adopted and its legal effect depend on the authority having jurisdiction.
Record the exact source used. Do not combine separate requirements into one unsupported universal rule.
Address Transportation-Related Odorant Fade
For specified cargo tanks and portable tanks leaving a refinery, gas plant or pipeline terminal, 49 CFR 173.315(b)(2) requires the offeror to maintain procedures addressing odorant fade during transportation.
The regulation addresses:
Quantitative testing of the amount of odorant
Manual-injection checks
Calibration checks for automatic injection equipment
Notification and quality control for new, recently cleaned, corroded or oxidized tanks
Inspection for oxidation or corrosion
Corrective action needed to ensure enough odorant remains during transportation
This is not a universal quarterly testing rule for every LP-Gas facility. The operating record should identify when the transportation provision applies and who is responsible for each required action.
Evaluate Petroleum-Gas Pipeline Systems Separately
Some petroleum-gas pipeline systems are subject to 49 CFR Part 192. 49 CFR 192.11 connects covered petroleum-gas systems with Part 192 and the applicable scope of NFPA 58 or NFPA 59.
Where 49 CFR 192.625 applies, it addresses detectability, odorant characteristics, introduction without wide variations and periodic sampling with an instrument capable of determining the percentage of gas in air at which odor becomes readily detectable.
The article previously treated that pipeline provision as a universal LP-Gas testing rule. It is not. Applicability should be established from the actual system and jurisdiction.
Build a Method-Specific Verification Plan
A useful plan separates the questions being answered.
Odorant addition or concentration
A quantitative method can help determine the amount added or the concentration of a target compound within the method's capabilities. Record:
Product and odorant
Method and measurement units
Instrument or laboratory identification
Calibration or quality-control basis
Sample location and container
Date, time and responsible person
Applicable criterion
Limitations and corrective action
Do not publish an accuracy value for a portable analyzer unless it comes from the current documentation for the exact instrument and measurement range used.
Gas-in-air odor intensity
An odor-intensity method evaluates the gas-in-air percentage at which odor becomes readily detectable under the selected procedure. It does not quantify sulfur concentration and should not be reported as though it does.
The record should identify the procedure, equipment, environmental conditions, tester requirements, result, applicable criterion and limitations.
Concentration and perceived odor intensity are different evidence. Neither replaces combustible-gas detection or an approved leak-response procedure.
Select Representative Locations and Conditions
Testing should reflect the operating boundary and the condition being evaluated.
Potential factors include:
Product source or batch
Storage or transportation container
New, cleaned, corroded or oxidized equipment
Transfer and receiving points
Active pipeline source and flow direction
System extremities where applicable
Low, intermittent or zero-flow periods
Temperature and time since odorization
Changes in supplier, odorant or operating configuration
Locations associated with an unexplained result or odor report
For each result, record what the sample represents and what it does not represent. A result from one container, batch or operating state should not be described as proof of every condition.
Set Frequency and Retention From the Applicable Program
The previous article prescribed quarterly testing and two-year record retention without establishing a governing source. Replace those blanket periods with a documented basis.
The plan should identify:
Applicable requirement or operator procedure
Trigger and testing frequency
Event-driven tests after relevant changes
Responsible person
Review and escalation path
Corrective-action authority
Record-retention basis
Conditions for returning to normal operation
Transportation procedures, workplace requirements, pipeline sampling and operator quality-control programs may have different triggers. Use the rule and approved procedure that apply to the actual scope.
Respond to Odor Reports Through the Approved Process
An odor report may involve a gas leak, an odorant release, under-odorization, overodorization, masking, fade or another source. It should enter the responsible operator's approved emergency and leak-response process before being classified as an odorization issue.
Odorized gas is supplemental leak awareness. It is not a substitute for combustible-gas detection, dedicated toxic-gas detection or the site's emergency program.
Build the LP-Gas Odorization Record
A turnover or operating record may include:
Product, supplier and batch information
System and jurisdictional boundary
Applicable odorization basis
Odorant and addition record
Container and equipment identification
New, cleaned, corroded or oxidized equipment status
Injection and calibration checks where applicable
Quantitative concentration results
Gas-in-air odor-intensity results, clearly distinguished
Sampling locations and operating conditions
Deviations, notifications and corrective actions
Responsible review and acceptance
Unobserved conditions and remaining monitoring requirements
The record should disclose limitations instead of implying universal compliance or performance.
LP-Gas Odorization Support From BPS
For a qualifying scope, BPS can discuss operational planning, vendor-neutral field measurements and organized documentation. Review Pipeline Operations and Maintenance for related operating-support capabilities.
Send the facility location, product, operating objective, container or pipeline-system type, governing jurisdiction, odorant basis, testing method, available records and requested support, or call (323) 609-5009.
BPS provides operational support and documentation, not legal advice.
Frequently Asked Questions
Is LP-Gas the same as natural gas?
No. LP-Gas is predominantly propane, propylene, butanes, butylenes or mixtures of those hydrocarbons. Natural gas and LP-Gas should not be treated as interchangeable products or regulatory categories.
Does every LP-Gas facility use the same testing frequency?
No. Frequency and triggers should come from the applicable requirement, transportation procedure, operator program and actual system conditions.
Does an odorant concentration result prove odor intensity?
No. Chemical concentration and perceived gas-in-air odor intensity answer different questions and should be recorded separately.
Does odorized LP-Gas replace combustible-gas detection?
No. Odor provides supplemental awareness. It does not replace dedicated detection or the responsible operator's approved emergency and leak-response procedures.
