Sniff Tests

Updated: Mar 27, 2018

The nose knows.

In our high tech world today we have gadgets and apps for everything. Sometimes though, the simple and best tools are right in front of our face. Yes, your nose. It usually works well and is cost effective.

A sniff test can tell you a lot about propane. Does it have odorant? Is it possibly contaminated with ammonia or high sulfur content? With a normal person and a good stiff test program that is properly implemented these three issues are likely to be identified. There are issues such as someone with a sinus condition, head cold, smoking or the use of alcohol or drugs that will decrease the ability to smell. This is all the more reason to have more people involved in sniff testing programs.

The NFPA 58 says that odorant shall be determined by sniff-testing or other means and the results shall be documented, (1) when product is delivered to the bulk plant (2) when shipments bypass the bulk plant. Transport operators should also document on the bill of lading at the terminal that product is properly odorized. Bill of ladings should specify the type of odorant and the amount used. It is required to be 1 pound per 10,000 gallons of propane but it is common to use 1 ½ to 2 ½ pounds per 10,000 gallons.

A sniff test is performed by simply venting a small quantity of liquid through a # 54 vent outage gauge and then closing the valve. Sniff the area after the liquid vaporizes. It should go without saying, but wait till it vaporizes. I have actually heard of a guy freeze burning his nose doing a sniff test! Verify the product is odorized or that there is not anything that smells unusual such as ammonia or sulfur. If unsure, notify your supervisor or a qualified individual to do additional tests. Red litmus paper tests can show ammonia contamination and lead acetate paper will show hydrogen sulfide. It might be necessary to have a stain tube test performed. There are many field tests available. If unsure of your product quality, ask an expert.

The following is a recommended sniff test program: 1. Ask your transport operators to sniff test and document the test on their paperwork. 2. At the bulk plant to designate someone to perform a sniff test on the storage tanks daily or at a minimum of each time a new load is delivered. 3. Ask each bobtail driver to sniff test and document, each time the bobtail is loaded. 4. Dispenser operators or people filling cylinders should also perform and document the tests.

This gives you a minimum of three noses before the propane gets out of your plant. Three noses documented that they smelled odorant in the gas. Three noses didn't detect a potential contamination. If you are in a one person plant it is two different noses (you and the transport operator) and at three different times in the distribution process. Loading on the transport, unloaded into the bulk storage and loaded on the bobtail. If an odorization case goes to trial, you might just win.