The following article was written by Russell Warn and published in ISHN magazine (ishn.com), December 2016. Roco comments have been added to the article and are noted in red.

Working in confined spaces presents a unique and dangerous challenge in combatting the unseen – oxygen deficiency, poisonous or explosive gases, and other hazardous substances are among the most frequent causes of accidents associated with work in confined spaces and containers.

From 2005-2009, the Bureau of Labor Statistics reported nearly two deaths per week, or roughly 96 per year, could be attributed to confined space, with about 61 percent occurring during construction repair or cleaning activities.

With conditions subject to change in a moment’s notice, taking steps to protect against life-threatening dangers should always be a top priority in confined spaces. Performing a thorough clearance measurement is a demanding — yet crucial — task that dictates the safety environment, and should not be taken lightly. To help guide you along your road to enhanced safety, outlined below are several best practices based on frequently asked questions.

When should I perform a clearance measurement?

Conduct clearance measurements immediately before operations begin. Environmental factors such as temperature and air flow can change the atmosphere, causing readings to fluctuate. One shift’s measurement taken at 7 a.m. is not representative of the conditions when work operations commence for another shift at 4 p.m. New clearance measurements must be taken immediately to account for the nine hours of changing temperatures and ventilation patterns, depicting the accurate readings of present conditions.

Roco Comment: In addition to pre-entry clearance measurements, entry into permit spaces during construction activities requires "continuous atmospheric monitoring" unless the entry employer can demonstrate that equipment for continuous monitoring is not commercially available or periodic monitoring is sufficient. Ref. 1926.1203 (e)(2)(vi), 1926.1204 (e)1)(ii), and 1926.1204 (e)(2). Additionally, Roco believes that for "ALL" permit entry operations, it is advisable to provide continuous atmospheric monitoring no matter what the industry activity entails.

What’s the importance of zero-point adjustment?

When performing clearance measurements, it’s crucial to determine the reference point of the gas detector by calibrating the zero-point. The zero-point ensures that the indicated values correspond to the actual existing gas concentrations. In order to determine that the actual zero-point has been found, calibrate equipment in an environment where the hazardous substance is not present, such as fresh air environments. With every scientific test, no matter the field, a control group, which serves as a starting point of reference, permits for the comparison of results to show any contrasting changes. The zero-point calibration acts as such, allowing workers to identify the presence, or lack thereof, of different gas concentrations.

Where do I measure/take the sample?

When it comes to measuring samples, there are four things to keep in mind: the physical properties of gases, and the type and shape, temperature and ventilation patterns of the confined space.

Know the differences between light and heavy gases. Clearance measurement experts must have a strong working knowledge of hazardous substances’ properties, as they play a role in where measurements should be taken. For example, if a sample is pulled from the top of the confined space and hydrogen sulfide (H2S) is detected, the sample may not be entirely reliable. H2S has a molar mass of 34 g/mol, which is significantly heavier than that of air (29 g/mol). As a result, H2S sinks to the bottom of a space, where its concentration would be greatest. Identifying a presence at the top of the confined space says immediate danger and appropriate actions should be taken.

Light gases quickly mix with air and rise to the top. As a result, any measurements in open atmospheres should be performed close to the leak, and increases in concentration should appear in the highest points of the confined space. Heavy gases, on the other hand, should sink and flow like liquids, pass obstacles or stick to them. They barely mix with air like light gases do, so their samples should always be taken at the lowest points of the confined space.

Determine the type/shape of the confined space: In an ideal scenario, each confined space area would be in an “even” or level position. This isn’t always the case, and a container may be placed on an inclined surface, making the highest point in the corner positioned toward the top of the inclined surface. Thus, entry may be nearer to where the heavy gases have accumulated.

Take tabs on temperatures. All matter is made up of atoms and molecules that are constantly moving. When heat is added to a substance, such as a gas, the molecules and atoms vibrate faster. As the gas molecules begin to move faster, the speed of diffusion increases. If the sun has been shining on a tank for hours, there’s a good chance the clearance measurement taken at dawn no longer reflects the current readings due to the increase in diffusion.

Vet the ventilation. Air currents change the position and concentration of air clouds, and often times, the way a confined space is ventilated can affect readings. Containers cannot always be separated from pipelines, or there may be leaks in the tanks that must be accounted.

Roco Comment: Not only is it required by certain OSHA provisions like alternate entry procedures, but Roco highly recommends monitoring the atmosphere prior to initiating ventilation. This is intended to provide a reasonable assessment of the potential atmosphere change should the ventilation equipment fail. The rate for a potential hazard to re-develop will be based on factors such as the effectiveness of isolation, any residual product within the space, temperature, humidity and passive ventilation which are among just some of the factors.

How do I safely conduct the measurement for an accurate reading?

People often question why they can’t just use the carrying strap of their device to lower the device into the confined space for a reading. Although this seems like a simple fix, it’s not a safe or recommended way to conduct the measurement. Lowering the device into the container this way not only obscures the way the display is read, but it may not audibly alarm. If the measured value is slightly below the threshold value and the alarm does not sound, a worker would not be notified of the dangerous concentrations lurking below. Not only this, but measurements may be inaccurate since the measured gases, due to their molar masses, may be concentrated at a higher or lower point within the container. Clearance measurements should be conducted on-site and on-the-ground of the confined space for accurate, safe readings.

Roco Comment: The points made in the preceding paragraph are certainly valid. The best solution that we can offer is to use remote sampling probes or tubes to actively draw (pump) samples from the stratified levels of the space while the direct reading instrument is in a position outside the space to observe the real time readings. To expound upon the point the author makes, if the pre-set threshold for the alarms are not enough to trigger the alarm indicating the presence of a hazardous atmosphere, and the individual performing the assessment relies instead on rapidly pulling the monitor from the space in the hope that they are able to read the display before the values change, is a very dangerous way of approaching this procedure. Depending on the sampling rate of the monitor, the hazardous gas(s) may have cleared from the monitor in the time it takes to withdraw it from the space, and it is very likely that the instrument will display a normal atmosphere by the time it is back within view. Additionally, for areas within the space that cannot be remotely assessed by remote sampling prior to entry, the only safe recourse is to limit entry to the areas that have been assessed and to take a monitor into the space to continuously assess the unreachable regions before venturing further.

What do I need to document during clearance measurement protocols?

Just as it’s important to remain thorough in clearance measurements procedures, it’s equally as important to remain thorough in the general housekeeping protocols surrounding samples. This includes documenting:

• • The container number
• • The measuring point of the container, and whether there was more than one measuring point
• • At which time was the clearance performed
• • Under what condition was the measurement performed
• • Measured hazardous substances
• • Name of person performing measurement
• • Equipment used for clearance

Safety, regardless of job title or responsibility, should be everyone’s top priority. When working in the midst of poisonous and explosive hazards, performing clearance measurements correctly and carefully means not only keeping one’s self safe, but keeping the working environment safe, as well.

About the Author:
Russell Warn is the product support manager for gas detection products at Dräger. He has been in the safety industry for more than 29 years, with most of this time dedicated to gas detection product and application support.

As shown in this photo, an engulfment scenario was featured at last year's Rescue Challenge. Be aware...it only takes 5 seconds for flowing grain (or other product) to engulf and trap a worker.

In 60 seconds, the worker is submerged and is in serious danger of death by suffocation. More than half of all workers engulfed die this way. Many others suffer permanent disability.

OSHA has recently issued further warnings on the dangers of working in grain or bulk storage facilities.

An "engulfment" often happens when "bridged" grain and vertical piles of stored grain collapse unexpectedly. Engulfments may occur when employees work on or near the pile or when bin augers whirl causing the grain to buckle and fall onto the worker. The density, weight and unpredictable behavior of flowing grains make it nearly impossible for workers to rescue themselves without help.

"Far too many preventable incidents continue to occur in the grain-handling industry," said Kim Stille, OSHA's regional administrator in Kansas City. "Every employee working in the grain industry must be trained on grain-handling hazards and given the tools to ensure they do not enter a bin or silo without required safety equipment. They must also take all necessary precautions - this includes using lifelines, testing the atmosphere inside a bin and turning off and locking out all powered equipment to prevent restarting before entering grain storage structures."

In 2016, OSHA has opened investigations of the following grain industry fatalities and incidents:

• March 16, 2016: A 42-year-old superintendent at Cooperative Producers Inc.'s Hayland grain-handling site in Prosser, Nebraska, suffered fatal injuries caused by an operating auger as he drew grain from a bin. OSHA cited the company on Sept. 9, 2016, for three egregious willful and three serious violations and placed the company in its Severe Violator Enforcement Program. The company has contested those citations. See news release here.
• March 22, 2016: A 21-year-old worker found himself trapped in a soybean bin, but escaped serious injury at The Farmer's Cooperative Association in Conway Springs, Kansas. Rescue crews were able to remove the worker and he was treated and released at a local hospital. On June 2, 2016, OSHA cited the company for 13 serious violations.
• March 25, 2016: A 51-year-old employee was trapped in a grain bin at McPherson County Feeders in Marquette, Kansas. Emergency crews were able to rescue him. OSHA cited the company for four serious violations on April 14, 2016.
• May 19, 2016: A 53-year-old male employee at Prinz Grain and Feed suffered severe injuries on May 18, 2016, as he worked in a grain bin in West Point, Nebraska. The maintenance worker was in a grain bin when a wall of corn product collapsed and engulfed him. He died of his injuries two days later.
• Sept. 1, 2016: A 59-year-old employee suffered severe injuries to his leg when the sweep auger inside a bin at Trotter Grain in Litchfield, Nebraska, caught his coveralls.
• Sept. 19, 2016: A 28-year-old employee of the Ellsworth Co-Op in Ellsworth, Kansas, had his left leg amputated when he stepped into an open auger well inside a grain bin while the auger was running.

"It is vital that we work with leaders, farmers and those employed in the grain and feed industry to increase awareness of hazards in the grain industry and discuss ways to protect workers on the job," stated an Omaha OSHA official.

We add that it’s critically important for emergency responders to be aware of the dangers they may face in bulk storage facilities. In addition to engulfment, there’s also the risk of dust explosions as well as entrapment from moving mechanical equipment.

Does a competent person inspect your rescue equipment each year?

If not, you may want to consider having an independent third party perform the inspection for you. This service is offered by Roco as a stand-alone service, or it can be added to your next private training session. 

Functional Ops Check

The service includes a “sight and touch” functional inspection of hardware, nylon products (including rope, webbing, and anchoring components), harnesses, and accessory equipment (including litters and stretchers) utilized in confined space/high angle applications. The inspection will be conducted in accordance with manufacturer’s specifications and will satisfy the requirement for an annual² inspection by a competent person.
Note: Equipment recommendations will NOT be provided by inspection personnel unless requested to do so.

Service Inspection Benefits include:

• Certified personnel to inspect equipment to manufacturer's standards.
• Inspection documentation from an independent third party.
• Frees your personnel from the responsibility of equipment inspections.

A full report of findings will be provided to include accessibility of equipment to responders and any other recommendations to improve overall team performance. It will include other pertinent information such as the manufacturer, product number, and serial/lot number (where applicable), date of manufacture, and in-service date (when available). It will also include the results of pass/fail testing for both visual and functional inspection. All equipment deemed unsuitable for use will be tagged for removal from service.

Regardless of the stated service life, the condition of equipment – as determined through inspection by a qualified party – is a key factor in determining whether or not a piece of equipment is fit for service.

Although the definition of “equipment lifespan” is very broad depending on the manufacturer, each provides specific instructions on proper inspection of equipment and detailed explanations on when to retire the service item. Several general identifiers that pertain to all equipment are shown below.

Reasons for Equipment Retirement include:

• Item fails to pass any pre/post use or competent person inspection.
• Item has been subjected to a major fall or load.
• Item is constructed of plastic or textile material and is older than 10 years.
• You cannot determine the complete full-use history of item.
• You are not certain or have lost confidence in the equipment.

As a reminder, it is very important to keep the manufacturer’s instructions when purchasing new equipment. This is vital to identifying and keeping track of the manufacture date as well as other important information. For example, if the manufacture date of equipment, such as life safety rope and harnesses, cannot be identified; it can pose extreme liability for agencies or facilities whose teams may potentially be operating with equipment that has passed its service life. It could also create a compromise in the safe operation of the equipment.

A 10-year service life for nylon/polyester products is set according to ASTM F1740-96 (American Society for Testing and Materials).

Inspect Rescue Equipment Every Time It’s Used

All team members should be qualified and knowledgeable enough to perform pre- and post-use inspections of equipment. It is crucial that all members document each use of equipment, denote any deficiencies, and report to the proper person. One person should be designated to perform the competent person annual inspection. This person should have complete knowledge of the equipment and inspection procedures as well as the authority to keep or remove equipment from service as they see fit. If team members are unable to fill this role, a qualified third party with applicable manufacturer certifications in competent person inspection should be utilized to assist in determining the condition and estimated service life of rescue equipment.

Download Roco's Quick Checklist for your convenience. →

Rescue team members are encouraged to attend this inspection where they will receive information on proper pre- and post-use inspections for their equipment. Guidance can be also offered in areas of equipment care, inspection, record-keeping, and proper storage. Again, equipment recommendations will not be addressed unless specifically asked to do so – this is only an inspection of the equipment you currently have on site.

Remember, with rescue gear, lives are literally “on the line,” – if in doubt, throw it out!

To schedule your Roco Competent Person Inspection, or add it to your current training dates, call us at 800-647-7626 or email info@rocorescue.com. Roco offers this service at no charge for current customers or for a very nominal fee for non-customers.¹

¹ Current customers receive a one-day equipment inspection at no charge. Travel expenses apply for out-of-town customers.

² References include: 1926.502 Appendix C; ANSI Z359.2 Section 5.5.2 Inspections; ASTM Rope Inspection Guide; NFPA 1983 Section 5.2; ANSI Z359.11 Annex A (harnesses); and ANSI Z359.4 Section 6.1.

NOTICE: The client remains responsible for ensuring that all guidelines and requirements for maintaining and, where indicated, removal of equipment from service, are followed. This includes removing equipment from service anytime there is a situation or incident that occurs during handling, training, or rescue, that might have caused damage or otherwise compromised the integrity of the equipment, particularly where internal damage that is not visible might be present (e.g. equipment dropped from height, exposure of nylon products to chemicals or other potentially degrading substances, etc.). Client will be required to complete a certification that between Roco inspections, the equipment was properly stored, was available only to personnel trained to use the equipment properly, and that any equipment that was exposed to any condition or occurrence that could have resulted in hidden damage has been removed from service. A company representative, preferably someone from the rescue team, must be present during the inspection process.

By Pat Furr, Safety Officer & VPP Coordinator for Roco Rescue, Inc.

I have written previous articles on modern equipment and I do have my all-time favorite piece of kit that in my 36 years of bending rope has earned the title of the best piece of equipment in my view. It is my choice for that title because it is versatile, safe, and efficient. Second in line on my list of all-time favorites is the Omni-Block/CMC PMP Swivel Pulley. If you have not used this pulley yet, I suggest you beg, borrow, but don’t steal one.

So what’s so great about this pulley? For starters, the materials and the bearings of this pulley are gem like. The quality of build and the bearings reduce stiction (static friction) at the sheave axle increasing efficiency, even for such a small tread diameter. But the real advantages of these pulleys are the built in swivel and the swinging side plate. There is a story about the swinging side plate that I may tell you some day. Here is a hint: If you have what you think is a good idea, don’t hesitate in exploring that idea further. If you wait, you just may miss a great opportunity.

The built in swivel has several benefits. For situations that call for a swivel built into the system, you can accomplish with a single piece of equipment what would normally require three separate pieces. By having the swivel built in, you eliminate a separate swivel and the carabiner needed to connect it to the pulley. Less weight and less likelihood you have to dig or go searching for a separate swivel and extra carabiner. For directional pulleys the built in swivel aligns the side plates with the direction of pull and eliminates chafing between the rope and side plate which increases efficiency.

Another advantage of the built in swivel is while building or operating Z-Rigs and blocks and tackle (BT). For vertical BTs, the load can stay in any orientation with no fear of putting twists into the lines or creating side plate interference. Additionally, if you are not paying attention while building a Z-Rig and create a twist in the ropes coming from the first change of direction at the anchor to the pulley and then the haul line, it would normally create a lot of friction as the second and third sections of rope cross each other. But with the built in swivel, any twists in those lines will spin clear as soon as you put any tension on the haul line. It’s like magic.

The swinging Prusik minding side plate has a double action lock that when operated allows one side plate to open to mount or dismount the rope while the pulley is still attached to the carabiner. This feature alone makes this pulley unique in its function.

For a series of directionals that need to be disassembled as the rescue progresses, this will speed the operation up significantly. But my experience with this pulley - especially for tower rescue- is the reduction in the potential to drop the pulley. In fact my tower rescue set up relies on a one piece mechanical cam, a carabiner and this pulley and they never have to be disconnected from each other! I have seen the incidence of dropped objects practically eliminated during the tower recue classes I teach just because of this one change.

The swinging side plate really shines during the construction of a Z-Rig. It is so simple to mount the cam, carabiner and pulley as a three piece set onto the mainline and then simply mount the rope into the pulley and close it up. Remember, if you managed to build any twists into the 2nd and 3rd lines, they will spin free as soon as you pull the haul line.

In single sheave versions these CMC PMP Swivel pulleys come in three sizes. 1.1”, 1.5”, and 2.6”. The 1.1” is NFPA rated for Technical Use, while the 1.5” and the 2.6” are NFPA rated for General Use. They will all accept up to 13mm rope. The Double Sheave version does not have a Prusik minding feature, but does have a becket. Both side plates have the dual action release button for ease and speed of loading the rope(s).

It is hard to put into words just how efficient these pulleys are until you use them in your rope systems. But I hope I have piqued your interest enough to look into them.

By Josh (JC) Hill, Roco Technical Equipment Manager & Chief Instructor

As mentioned in our original story, the alarming statistic of confined space fatalities still proves to be accurate – approximately 60% of fatalities in multi-casualty incidents are the “would be rescuers.” In January, it happened once again. Four construction workers had entered a drainage manhole to determine why the newly paved road was settling in that location.

Upon entering the space, which is believed to have been done without initial monitoring or ventilation, the worker collapsed. As is seen much too often, a second worker entered the space to assist the downed worker and was rendered unconscious. A third worker entered the space and again succumbed to the atmosphere.

The 911 system was activated and responders from the Key Largo VFD arrived at the scene and prepared to enter the space to perform rescue. Initial reports state that a volunteer firefighter donned an SCBA for respiratory protection and attempted to enter the manhole. He found the space to be too confining and removed his SCBA to make entry. He was in the space for approximately 20 seconds prior to being overtaken by the atmosphere. Note: It is our understanding that proper monitoring of the confined space had still not occurred at the time of the firefighter’s entry to attempt rescue.

Another firefighter then entered the space and recovered the first firefighter from the deadly space. Medical attention was provided until he was airlifted to Jackson Memorial Hospital’s Ryder Trauma Center. The Miami-Dade County Haz-Mat Team was also called to the scene.

After proper monitoring of the space, it was determined that rescue was no longer a viable option and that the scene would be transitioned to recovery efforts. The testing of atmospheric conditions showed the space contained significant levels of hydrogen sulfide and methane gas with decreased levels of oxygen.

Although original reports did not give indication of toxic gases, the signs surrounding the events make it obvious that the potential was there. To have several workers enter a space like this and rendered unconscious in short periods of time is a classic scenario involving atmospheric hazards. This combined with several statements from neighbors that the area smelled of “rotten eggs” for months provide significant clues to atmosphere being a significant contributing factor to the emergency.

So, why do these confined spaces incidents continue to occur across the nation with emergency responders?

When you break it down, the reasons are fairly simplistic and very alarming. Most citizens have a misconception of fire departments and emergency responders. Most often, it is assumed that if you call the fire department, whether in a large municipality or small township, the personnel responding will be qualified and equipped to perform any task needed.

Fact is the vast majority of fire departments are trained and equipped to perform basic first aid and life support along with standard firefighting operations.

Funding has and will continue to be the major handicapping factor that limits the capabilities of these agencies. Unfortunately, it usually takes a catastrophic event before funding is provided.

Also, unless dedicated specialty teams are established, it is practically impossible for agencies to train each individual to a proficient level for technical rescue and hazardous material response and have them maintain this level without regular, on-going training. It is also unrealistic for departments to outfit each individual responding unit with all of the necessary equipment to respond to every conceivable scenario.

As we all know, emergency responders are built around running towards the danger when human life is at risk. This attitude is what separates them from the average population and makes them successful at protecting life and property.

However, when not properly trained to react and respond to these types of uncommon hazards, the results are often as unfortunate as what we witnessed in Key Largo.

So, how can we change these alarming statistics for emergency responders?

First of all, it is critical that responders understand the unseen hazards they could be exposed to during these types of hazardous confined space operations. It is imperative that all personnel – from the newest rookie to the incident commander – understand what they are facing. Emergency responders must be able to recognize when they are not adequately trained or equipped for an event or hazard. They must understand that their lives are on the line in these hazardous environments.

Firefighters, from the smallest volunteer departments to the largest municipalities, must be trained to recognize the signs of hazardous environments and understand that they would be putting themselves in grave danger if they proceed with rescue attempts. Supervisory personnel should receive additional training that provides the knowledge to understand their full capabilities when facing scenarios they are not properly trained and equipped to safely handle. To stand-down is the wisest decision to protect their personnel from severe injury or death when the chances of successfully performing rescue have little to no chance for success.

It’s a difficult choice – risk vs. reward. But it’s a critical decision that emergency responders must make every day. Their personal safety must come first – it must be a viable rescue before they put themselves in harm’s way.