If you spend any time around Anhydrous Ammonia, you know how easy it is to detect its presence; however, if you have ever tried to find the leak causing the issue, it can be extremely difficult. One of the most common, simplest, and cheapest methods is using sulfur (or sulfur) sticks. These have been around for generations in facilities handling ammonia, and I am not sure of their whole history, but I can attest to their effectiveness and ease of use. But as a safety professional, I have some concerns with their use and wide acceptance as the “only method that makes sense to locate leaks.” I will frame my concerns in terms of OSHA’s minimum compliance requirements. Now I am in NO WAY suggesting these devices NOT be utilized, but using them comes with some level of risks and advantages; so I am just trying to start the discussion by asking the questions and trying to use a situation as a learning experience that is much more than just about the use of sulfur sticks.
Here is a scenario to consider… A leak has been identified by odor, and io find the exact leak point, operators use sulfur sticks, which require the stick(s) to be lit using an open flame. My questions:
1) Does anyone issue a HW Permit for the use of these sticks? Both the lighting of the sticks and the sticks themselves would qualify as Hotwork in many facilities. Albeit the open flame is small, many facilities would fire someone if they engaged a lighter or struck a match in a process area(s), so how can we not call the use of these sticks “hotwork”? I am well aware that there is a significant difference in the level of risk between a cutting torch and a sulfur stick, and bic lighter. However, the discussion still needs to happen – where do we draw the line in our control of ignition sources within our process areas?
2) What kind of controls (i.e., procedures) are in place for the use of these sticks in leak detection? From a PSM perspective, the use of these sticks is a “non-routine task” (or at least it should be!), and many process safety professionals will state these types of tasks are those that should be “permitted tasks”. Without a doubt, there is a need for either an Operating Procedure or a Maintenance Procedure (depending on how you classify the task). But how many facilities have a procedure on the safe use of these sticks? Does the procedure establish a limit of NH3 in the atmosphere as to when the sticks can NOT be used, such that someone who wants to use them in a large release (i.e., emergency response) would be prohibited from doing so? Who is permitted to use the sticks? What training do the users need to use the sticks safely?
If you want to lose sleep at night, poll your emergency response team and ask if they would use a sulfur stick while wearing a LEVEL A or B ensemble searching for a leak.
If a facility has no procedures for the use of these sticks, what is the argument for not having procedures for their safe use? What would be the argument not to call this hot work and not issue a HW permit? If we claim the use of an open flame to ignite the stick and the glowing red stick is not an ignition source, why do we prohibit cell phones in the area?
I am sure there will be those who scoff at the idea of issuing a HW permit when we have a leak and say that the permit brings no safety benefit to the use of the stick(s). Those will argue that “wasting the time to get the permit could make the leak bigger” and thus more dangerous. And to be truthful, I would agree to some extent, but those are diversions from the basic question:
Is lighting a sulfur stick an open flame, and would this not fall under your hot work permit requirements?
Would a PSM-covered process not be required to have a procedure for its use?
Now for a twist to this little story… how many have heard of dissociated ammonia? This is when Ammonia is broken down into Nitrogen and Hydrogen at very high temperatures (+900ºF). Imagine smelling ammonia and grabbing a sulfur stick to find the leak. You can imagine what this could lead to! There are those that will claim anyone who would use a sulfur stick in a hydrogen atmosphere is just “dumb,” and that no amount of safety procedures or training will save them. Of course, none of us have done anything dumb, and the 12,000 photos I posted at SAFTENG are all setups and unreal! My favorite response when someone claims safety is “common sense” is from the great Forrest Gump… Stupid is as Stupid does. If a facility sends some workers to an “ammonia safety course” to learn more about how to “safely” handle ammonia and they learn about these cheap and easy-to-use sticks and are told “they are as safe as it comes… hardly any risk at all… the fastest way to find a leak… much safer as an alternative… no business handling ammonia should be without them…” why would they not think this is what the business needs. After all, their process is covered because of their anhydrous ammonia, and they need help.
So does everyone have a procedure, limiting the uses of these devices? How many are issuing HW permits for their use?
NOTE: 2017 UPDATE
IIAR’s 2014 edition of ANSI/IIAR 2 – Standard for Safe Design of Closed-Circuit Ammonia Refrigeration Systems states the following regarding the use of sulfur sticks..
6.5 Open Flames and Hot Surfaces. Fuel-burning appliances and equipment and surfaces with temperatures exceeding 800°F (427°C) shall not be installed in a machinery room.
EXCEPTIONS:
1. Fuel-burning appliances and equipment shall be permitted in a machinery room where combustion air to the fuel-burning appliance is ducted from outside of the machinery room and sealed to prevent ammonia leakage from reaching the combustion chamber.
2. Fuel-burning appliances and equipment shall be permitted in a machinery room where an ammonia detector is in accordance with Section 6.13 and automatically shuts off the combustion process upon detection of ammonia.
3. The use of matches, lighters, sulfur sticks, welding equipment, and similar portable devices shall be permitted EXCEPT when charging is being performed and when oil or ammonia is being removed from the system.
4. Internal combustion engines powering compressors shall be permitted in a machinery room.