Dressing divers and tenders for Mass Casualty Operations
In parts I and II we discussed the initial steps for becoming prepared to manage a mass casualty water-related disaster such as a bridge collapse with multiple vehicle submersions. Drill training sessions were introduced with surface and subsurface personnel working around vehicles stacked up on land. This article discusses the minimum equipment needed by divers and tenders. One goal of this article is to help you make safe, effective equipment decisions as an educated consumer.
The first step is to determine what personal protection equipment (PPE) is necessary to keep divers and surface support safe. The most important rule to follow is that if the water has not been tested consider it a hazmat dive. It is the responsibility of the diving supervisor to review available environmental data and verify that the personal protective equipment (PPE) is appropriate for the intended use or both divers and tenders. Tenders are as important as divers, yet they are often forgotten in regards to hazmat PPE.
Diving supervisors should evaluate ALL equipment including small items. We have watched too many “PSD Hazmat” instructors list knives as an acceptable cutting tool for divers, for example. They are not thinking about the real world. They are not thinking about the reality of accidentally puncturing a drysuit while attempting to cut away an entanglement in zero-visibility or cold water. And aside from PPE, are dive supervisors confident that local EMS and hospital personnel are prepared to manage hazmat-related, gas bubble injury, hypothermia-related, or drowning dive accidents?
Chief Cameron Jones, an experienced diver trainer for the Canadian Navy and public safety teams worldwide describes three levels of hazmat in a very accessible manner. “If the water is safe enough for swimmers with a maximum problem of swimmer’s itch, then the category is hazmat 1. Hazmat 2 would be the final pond of a sewage treatment center, namely the water that gets dumped into the lake or river. The first pond of a sewage plant is considered Hazmat 3.”
A mass casualty incident would be designated as hazmat 2 or 3. A single vehicle immersion brings a pristine lake to a Level 2 environment due to the fuels and possibly biohazards now in the water.
Hazmat 1 equipment includes standard recreational scuba equipment with the addition of quick-release pony bottle systems, diver harnesses, tether lines, multiple cutting tools, and hopefully electronic communication systems (ECS). Remember that PPE does not solely relate to hazmat, rather it must protect personnel from any potential hazard. Most PSD involves debris-covered-bottom dwelling divers in little to zero visibility, which means having proven tested contingency plans and equipment to manage a blackwater entangled-out-of-air-diver incident. This requires direct line access between the needy diver and a shore crew consisting of the diver’s tender, a fully dressed backup diver with a tender, and a 90%-ready diver. The direct line access is accomplished with tender-directed-solo-tethered diving that provides optimally safe and effective searches. A regulator with an 80 cuft contingency tank in a harness that has appropriate tools mounted on it should be readily available for the backup diver to bring down to a primary diver in need.
ECS are highly recommended, if not mandatory, for overhead environments (i.e. ice diving, underwater vehicle extrication) and other high risk dives. Hardwire ECS are more recommended than wireless in most cases. If divers are tethered then the hardwire comm. line becomes the diver’s tether line. Hardwire ECS are easier to use and tend to be more reliable. Surface stations are less recommended than a portable box worn by the tender with a head set to allow full tender mobility, and diver-tender privacy. Divers who know that their breathing sounds and words are broadcasted over a surface station may be more stressed and less willing to admit to having problems or fears. Also, tenders cannot count a diver’s breathing rate in overhead environments if multiple divers are sharing a surface station, while it is very easy to do so with hardwire ECS.
Far too much PSD is conducted with sport diving octopuses that are nothing more than a second mouthpiece off a single air source. The octopus was invented by Walt Hendrick Sr. and Dave Woodward for high visibility, midwater, shallow, buddy, sport diving. The only similarity between those conditions and PSD is shallow water. Octopuses, spare air, or Air II’s have no place in PSD.
Another common error is back-inflated buoyancy control devices (BCD’s) that were created by the recreational technical dive industry for ‘rec tech’ divers wearing multiple, large volume, heavy steal cylinders. PSD divers have no need to waste money on heavy steel cylinders, and do not need multiple main cylinders or large volume cylinders because PSD bottom times should not exceed 20 to 25 minutes regardless of depth. Rather, PSD divers need to be able to effortlessly remain vertical on the surface, even when holding tools or a heavy recovered search object such as a body. PSD divers also need plenty of pockets for cutting tools, window punches, marker buoys, and a standard face mask, which back-inflated BCD’s rarely offer. With the increased number of dive stores selling PSD teams back-inflated BCD’s, we have observed an increasing number of diver near-panic situations on the surface characterized by attempts to keep their faces out of the water with rapid arm movements.
Additionally these BCD’s often cause potentially dangerous overweighting because they are significantly more difficult to fully vent at the surface. Every pint of air left in the BCD requires a pound of lead in compensation to make a diver neutral or slightly negative (1 lb) to descend. Back-inflated BCD’s are often weight integrated, which means if divers need to ditch their BCD/tank assemblies because of severe entanglement, then they are also ditching their weights, with resulting uncontrolled ascents to the surface or overhead environment. Some experienced PSD divers have made back-inflated BCD’s work for them, but they certainly are not recommended for newer divers and they beg the question of why not just get a BCD that does not present any of these problems and that is built for the PSD job?
Hazmat 2 requires the equipment for Hazmat 1 with the addition of properly tested hazmat drysuits with attached dry gloves and an appropriate fullface positive pressure/semi-positive pressure mask. The issue of “properly tested” is important to understand. Trellerborg Viking is credited with being the first drysuit manufacturer in the U.S. to test their suits with a rigorous battery of Hazmat tests, and is still one of the only suits to meet those high standards. Their test data is available for free at 800-344-4458 and is worth reading.
John Drewniak of Trelleborg states, “Hazardous material response teams can look to the National Fire Protection Association standards ( NFPA 1991, 1992, 1994) for material and suit performance to see what suits pass the standard. These standards are set
to offer a minimum protection factor for a list of chemicals which are done by a third party test lab and then audited by a separate company. The problem starts with the fact that there are no standards for equipment performance for dive gear.
Dive teams need to look at manufacturer test data and compare those
results to other manufacturers for results. But as there is no standard, the same chemical test can be performed in a different way making the data nearly impossible to compare. Viking has completed all tests to the same standard used in the NFPA 1991 standard for level A chemical suits with the same battery of chemicals and the same detection limits.
Example: The NFPA standard states detection levels of 0.1ug/cm2/min. The
European EU standard states a detection limit of 1.0ug/cm2/min or 10 times easier. If someone were to compare results on the same material done with these 2 different tests they would see a big difference in breakthrough results making one material look much better, when in fact it is the same material only tested differently.
Another problem is companies are now supplying data that does not represent
real testing but an estimation of the way the material will react to a certain chemical, i.e.: excellent, good, fair, poor. The problem here is: what is the difference between good and fair? Is it 5 minutes or 45 minutes? That is pretty important information to the guy getting in the water.”
When comparing test data, make sure that the entire suit was tested, not just a swatch of suit material, because a suit is only as protective as its weakest link (i.e. seals, zippers). We prefer suits made of EPDM (Ethylene Propylene Diene Mthylene) vulcanized rubber for a variety of reasons aside from their excellent hazmat protection.
- If punctured, these suits can quickly be repaired on scene immediately after immersion.
- They can be towel-dried and immediately put back in service after use, while other suits have to hang for hours to dry.
- They do not freeze easily between repetitive cold weather dives.
- They are inherently negatively buoyant so they do not require additional weight.
Note that teams should always use Hazmat 2 equipment if they have both hazmat 1 and 2 environments. A common error is to dive with wetsuits and other hazmat 1 equipment until conditions demand hazmat 2 PPE. This typically occurs when divers are not as comfortable in hazmat 2 PPE. Few PSD teams dive often enough to become reflexively comfortable in two different sets of equipment. Saving hazmat 2 equipment for only hazmat 2 conditions means using the more difficult, less well-trained-for equipment in the riskier and more difficult conditions. That makes about as much sense as putting the strongest divers in the water and backing them up with less comfortable and less experienced divers. Such unsafe, backwards procedures stem from an incorrect belief that “nothing will go wrong.”
If divers should not have their faces exposed to the water then a block should be used to allow divers to access pony bottle air without having to remove their full face masks. These blocks should allow backup divers to quick-connect their pony air to the primary diver’s block, thereby allowing a pony bottle-pass-off in the case of primary diver entrapment or entanglement. After backup divers pass off their pony air, they return to the surface for an 80 cuft contingency bottle or contingency surface supplied air that should then replace the pony air, thereby giving the backup diver plenty of time to free the primary diver.
There is controversy of whether teams should go with positive-pressure (PP) fullface masks or semi-positive pressure, sometimes incorrectly called demand. John Hott has been teaching divers to use and repair Intispero AGA masks, the most commonly used fullface mask in PSD, for ________ worldwide. His comments on this issue are, “
Hazmat 3 PPE requires surface supply diving, a heavy duty drysuit with attached helmet yoke and valves, attached dry gloves, contaminated water double exhaust valve on drysuit, inlet valve with double shut off, and a demand helmet with double exhaust valves. More serious hazmat conditions would warrant a heavy duty suit with attached free flow helmet (no neckseal or valves) with a double exhaust valve.
The following information on Hazmat 3 equipment is from Chief Jones.
EXO 26, AGA Mask, Superlite 17 A & B, are all good Hazmat level 2 masks, but they have limitations, which is why they cannot progress past this level. These masks and helmets are demand with a slight positive pressure. While Interspiro™ AGA still offers positive pressure masks, most teams stay away from these, as it requires extensive use to become both comfortable and proficient with these mask use so as to limit air loss through poor sealing or usage. If a team is using a vulcanized dry suit with a turbo hood and dry gloves along with one of these masks or helmets, they may think that they are totally encapsulated, and for more simple dive they may be. But the problem lies in what the divers position in the water column is during his/her tasking. While exhaling during a simple task or movement the diver may actually cause a slight vacuum in the mask or helmet thereby allowing ingress of contaminated water into the facial area. The demand regulator may then atomize this water in a vapour inhaled directly into the lungs, which is the worst case scenario of course, but possible. Just having the contaminated water around your nose, mouth, and eyes can cause problems for the diver.
Enter the Superlite 27 or any helmet that has a locking ring incorporated into the divers dress, with a double exhaust valve in both the helmet and the diver dress. The diver is now truly encapsulated. This truly makes the diver waterproof so to speak, because when the diver exhales the exhaust bubbles must travel through two one way valves on the exhaust system virtually eliminating the chance of the one way valve allowing small ingress of water during exhalation. This same method used for the suit, ensure no water enters the suit during exhausting of excess gas during ascent. Knowing the maximum immersion times of your suit in particular types of chemicals now becomes your biggest problem should the water be that contaminated. And of course you must also know the helmet’s capabilities in these environments. Having the full capabilities of your equipment in written format from the manufacture is the best way to plan diving in the high risk environment.
A few inexpensive ways to assist your team are as follows;
- buy bulk commercial dishwashing gloves, these are cheap and good for warm water environments, add to the exterior a cheap leather work glove and you add even more protection when searching the bottom of a debris laden body of water. These cheap dishwashing gloves seal just fine on the standard cuff rings. When the dive is done throw them away (remember they are now considered a bio hazard)
- use plastic kids pools for gross decontamination of divers before you begin finite decontamination. A plastic self pumping bug sprayer can also be filled with clean water for spraying down of divers where a water supply is not readily available
- Big Orange Glad Garbage bags (garden bags) are good for bagging all your equipment that is to be decontaminated at home base. This saves your boat, truck and other equipment from being cross contaminated. When done throw the bags away.
- Have laminated signs that state, HOT ZONE, WARM ZONE, COLD ZONE, AND MOST IMPORTANTLY FREE ZONE. The free zone is considered contamination free and therefore no contaminated equipment or personnel should be allowed there.
Working in a contaminated environment means more planning and preparation, but in the end it is a safer environment for your team. Remember, without any testing you must then assume it is contaminated. A good example of this is the Public safety Dive Team that is called to a local beach to search for a murder weapon. Because it is posted as safe for swimming they assume it is safe for diving. The weapon is located in 23 feet of water approximately 7 inches into the silt (long gun) The diver recovering it later breaks out in a rash that envelopes his entire body. While not life threatening it was certainly a big nuisance and he was off diving for 2 weeks. They kept referring to the fact that the local authorities had certified it safe for swimming through testing. It was, but who swims at 23 feet? No one ergo no testing done that deep or into the silt.
So why not recommend that dive teams always use Hazmat 3 PPE? There are several reasons why. The natural evolution for most PSD teams is to start out in Hazmat 1 scuba equipment, then progress to Hazmat 2 scuba equipment. At some point some teams face hazmat 3 dives and have to make the decision of whether or not it is feasible or reasonable to take the large leap to surface supply with helmets and suits meeting the hazmat PPE needs. It is a large leap for three reasons: cost, training, and time. One helmet typically costs more than many dive teams’ annual budgets. Now imagine outfitting six divers! Surface supply hazmat diving requires significant hours of training of both divers and surface support personnel, and it is especially difficult to find effective instructors who fully understand this type of diving for the PSD job. We have found that it is very rare for diver and especially tenders to be able to calculate basics such as surface air consumption rates or dive table profiles. Adding a very different type of diving with very different equipment and procedures may not be realistic.
Too often teams seek training from commercial or military hard hat divers who do not sufficiently understand the PSD job. A common example of an error that results from this is extended bottom times, with divers kept searching for 40, 50, 60 or more minutes, which are times well beyond optimal searching or safety capabilities for both divers and surface support. PSD team personnel usually have a much higher turnover rate than do commercial or military divers, which is an important part of the decision making process of whether a team should go surface supply hazmat capable. Additionally military and commercial divers typically dive far more frequently than do PSD divers, so instructors must continually understand that their students will not be able to maintain skills as easily. This plays an important role in how and what is taught in PSD surface supply hazmat programs.
Surface supply umbilicals are significantly more restrictive to diver movement than are standard rope tether lines. Umbilicals make searches for smaller objects more difficult and less effective and efficient. Surface supply equipment also make it far more difficult to perform three dimensional searches, namely those of objects raised off the bottom such as stacked vehicles. Surface supply divers work best when they are walking on the bottom, which is rarely the most efficient search method. Lastly, surface supply diving is more cumbersome to move to dive locations, and environments such as thin ice, may prohibit the use of it entirely.
PSD teams should coordinate training sessions with their Hazmat teams to make sure they can work together to properly clean divers post dive. This process normally involves three steps. Lt. (Navy, DCIEM) David Holland describes these steps briefly as:
“1) Gross decontamination at the shoreline or on the ladder, the fully dressed diver is rinsed with fresh water while exiting. Wash the diver from helmet down. Once out of the water or at top of the ladder, remove and rinse the weight belt.
The diver, escorted by tender (s) proceeds to the designated Decontamination station,
the helmeted diver is sprayed with fresh water and scrubbed with a soft bristled brush using an appropriate biodegradable protective clothing cleaner such as, Virkon© Betadine or Zepamine that is composed of powerful detergents and emulsifiers that help remove surface contaminants.
To stop hazmat chemical reactions a neutralizing agent, is often need. Then a thorough rinse with fresh water and repeat.
2) Diver undressing
is done carefully and systematically. Keeping the diver from becoming contaminated is the main concern. After doffing all outer ‘wet’ items, place equipment in suitable container(s) for subsequent cleaning, additional decontamination, inspection or disposal.
the undressed diver completes decontamination by removing undergarments and thoroughly showering to scrub skin clean and repeats before post dive medical assessment.
This is an essential step to ensure the health of the diver and the diver’s family.”
No one decontamination procedure works for all hazmat materials due to the different properties of toxic chemical or biological hazards. The optimum decontaminate method must be pre-planned before the diver enters the hazardous water so that the diver can safely go home after the dive.
In summary, departments who may have to respond to water-related incidents need to know the requirements of all possible types of operations in all water environments in their district. Then they need to decide what level of PPE is feasible and reasonable for their dive teams currently and in the future. Incident commanders should have a current list of commercial and other types of teams that can be accessed when the job at hand is beyond the capabilities of local PSD teams. Remember that there is only one mission that must be accomplished on every operation – go home when the job is done.