My article earlier this year about line breaks on relief valve vent lines that are attached to a header/manifold got a lot of you to ask more questions about the practice of “line breaking” (or as some call it “process opening”). I have tried to answer each question but thought it may be helpful to explain the fundamentals of safe line breaking. As we know, “line breaking” is the one safe work practice that OSHA and EPA mention in their process safety standards yet provides ZERO guidance on. We can not even find an RAGAGEP or consensus standard for guidance; however, we do have some excellent historically practices we can rely on.
PLEASE NOTE that UK’s HSE has an excellent publication “Guidance on permit-to-work systems”
First, the concept of “Permit to Work”
The one question safety professionals often get is “why do we have to have a permit for all these tasks?”. Safe Work Permits are designed to add a layer of administrative controls to some very hazardous and high risks tasks to both the worker(s) and or the facility. We are all familiar with Hot Work Permits and Permit Required Confined Space entry permits and the hazards associated with these tasks. So much like HW and PRCS entry, line break presents a high risk to the worker(s) involved with opening a normally closed system which contains a highly hazardous chemical. By making this high-risk task a “permitted task” we add a layer of protection (administrative control) by having a subject matter expert (SME) perform a hazard analysis which will identify additional controls needed for the hazardous task(s). This is why most permit to work programs prohibit workers from issuing their own permits; having a separate set of highly trained eyes involved in permitting the work that is NOT involved in the actual work will make us pause for safety and assess the risks outside the effort “to get the job done”.
Here is the best summary of how a work permit aids in managing risky tasks…
A permit to work is not simply permission to carry out a dangerous job. It is an essential part of a system which determines how that job can be carried out safely, and helps communicate this to those doing the job. It should not be regarded as an easy way to eliminate the hazard or reduce risk. The issue of a permit does not, by itself, make a job safe – that can only be achieved by those preparing for the work, those supervising the work, and those carrying it out. In addition to the permit-to-work system, other precautions may need to be taken (eg. process or electrical isolation, or access barriers)and these will need to be identified in task risk assessments before any work is undertaken. The permit-to-work system should ensure that authorized and competent people have thought about foreseeable risks and that such risks are avoided by using suitable precautions. Those carrying out the job should think about and understand what they are doing to carry out their work safely, and take the necessary precautions for which they have been trained and made responsible.
Today many facilities will even layer their safe work permits for certain high-risk work. This is done on purpose and in some cases a single task may require up to four permits, issued by several different personnel. For example, a line break permit may also include a LOTO permit in many facilities. And if the line break is being made by a contractor (a major no-no in some facilities) there may be a “contractor work permit” and if the break is to be made at an elevated location a working at heights (or aerial lift) permits may be issued.
Here are some things to consider for your “Line Break” program:
1) Make the task a “Permit To Work” (PTW)!
Granted, OSHA/EPA require a safe work practice for “opening process equipment or piping” many will notice that there is no mention of a requirement that the program/practice include a PTW. It is my opinion that having a “line break program” without a permit to go along with it is just a waste of good paper! Opening a process that contains a highly hazardous material may be one of the more hazardous tasks an operator or mechanic can do and not having this extra layer of administrative control is a major miss.
2) What chemicals/materials should be included in the program?
The scope of the program means a lot and many make the mistake of including ONLY their covered processes in their program so that they can “comply” with OSHA/EPA. But do we really think that any of the PSM/RMP highly hazardous chemicals are less hazardous to a worker opening the process merely because we are under the PSM/RMP pounds threshold? When it comes to opening process equipment or piping, the PSM/RMP thresholds mean very little to the worker(s) safety! In opening process equipment or piping 10 pounds of Chlorine, not the PSM 2,000 pound threshold, is all that is needed to pose a significant risk.
Although the PSM and RMP chemicals are a great place to start with making a list of inclusive chemicals, we should NOT stop there. Here is an easy method I have used over the years to assess chemical/material hazards and to aid in identifying chemicals/materials that should be included in the program:
• A Health (Blue) Rating of 3 or 4 in the NFPA or HMIS Labeling System, and/or
• A Flammability (Red) Rating of 3 or 4 in the NFPA or HMIS Labeling System, and/or
• A Reactivity (Yellow) Rating of 3 or 4 in the NFPA or HMIS Labeling System, and/or
• A solution with a pH of 9 or higher or a pH of 5 or lower (when concentration is unknown), and/or
• A solution with a temperature of 130°F or higher, and/or
• A solution with a BP<100°F, and/or
• A simple or chemical asphyxiant, and/or
• A combustible dust, and/or
• A gas/pressurized system that normally operates over 50 psi
3) As the work location goes UP so do the RISKS
I think we can all agree that “opening process equipment or piping” is quite hazardous at ground level but imagine “opening process equipment or piping” 30 feet in the air. I have seen first hand how bad things can get and how quickly they go south when working 30’ in an aerial lift, on scaffolding, or from a ladder and the line releases its contents! A lot of facilities have gone to a “working at heights permit” that is meant to aid workers in their protection against falls; however, working at heights while doing OTHER HAZARDOUS tasks can pose immediately dangerous to life and health atmospheres with very limited means of egress!
4) Vapor Pressure means a lot
Vapor Pressure (VP) is somewhat considered in the NFPA/HMIS labeling system, but some facilities have a neat way of using VP as one of the means to include materials that may fall through the cracks. I have used the VP of 50 mm Hg or higher as a means to identify materials that can pose an inhalation hazard and/or develop large hazardous vapor cloud (e.g. toxic, flammable or asphyxiant). Consider this: “opening process equipment or piping” that contains a hazardous material in liquid form can pose DUAL HAZARDS: liquid contact hazard and inhalation hazard if the VP is over 50 mm Hg. Common materials that would fit into this category would be Chlorine, Bromine, and Ammonia.
5) Egress is KEY!
Opening process equipment or piping in an area with POOR EGRESS, either because it is blocked by additional piping or the work is taking place at an elevated location should be considered EXTREMELY hazardous. So hazardous that poor egress will often-times result in additional layers of protection or increased CONTROLS to ensure the lack of egress is compensated for. For example, workers in an aerial lift opening a process line with a high VP chemical would require DOUBLE BLOCK isolation (engineering control/isolation), a stand-by person at ground level who is trained in the emergency operation of the lift, and the workers level of PPE may be increased to LEVEL A with a minimum of a 4500 psi pressure-demand SCBA (rated for 1 hour). I have even seen permits require a rescue team of three (3) be present during the initial break! Keep in mind that egress at ground level can become limited. Personnel involved in the permitting and the actual work MUST verify, and continue to verify, that the workers have a CLEAR and UNOBSTRUCTED egress path should something go wrong.
6) Safety Equipment
The closest safety shower and eyewash need to be identified during the permitting process, as well as the shower and eye wash flowed to ensure proper operation (as well as flushing it out). The nearest means to sound the alarm must be identified. This could be a phone, pull station, or maybe even the safety shower/eye wash if it is alarmed back to an occupied location (i.e. control room).
These are the basics of a solid line break/process opening program. Each and every line break or process opening that is NOT routine and therefore performed without the aid of a certified SOP and training MUST be viewed as a hazardous task. No two line breaks or process openings are alike – PERIOD! If the task is so routine, then the facility needs to implement a job SPECIFIC procedure for the opening. But let’s not fool ourselves that opening a chlorine line is the same regardless of where the actual opening will take place; an opening merely 10’ away may be twice as hazardous as the one performed weeks earlier. STAY ON YOUR TOES and keep your eyes open for the unexpected during all our line breaks!