Beyond the Rule of Thumb
Survival Tip 20
By Steven De Lisi
This edition of Hazardous Materials Survival Tips provides suggested responses to questions that appeared in the previous Survival Tip dealing with a scenario involving liquid leaking from the back doors of a tractor trailer parked at an interstate rest area. Information sources used to develop suggested responses include the Emergency Response Guidebook (ERG2004), the National Institute for Occupational Safety and Health (NIOSH) Pocket Guide to Chemical Hazards (NPG), and the Hazardous Materials Guide for First Responders (HMGFR), available from the U.S. Fire Administration. These documents were selected since they are easy to use and readily available at no cost to first responders. Although other reference sources can be used, determine if they would realistically be available during the initial stage of a hazardous materials incident.
The ERG is distributed to emergency response agencies through state coordinator offices. A list of contacts for each office can be found at http://hazmat.dot.gov/pubs/erg/statecoord.htm. The ERG can also be downloaded from the Web site of the Pipeline and Hazardous Materials Safety Administration at http://hazmat.dot.gov/pubs/erg/erg2004.pdf. The NPG can be downloaded from the NIOSH website at http://www.cdc.gov/niosh/npg/. Printed copies and CD-ROM versions are also available at that site. A CD-ROM version of the HMGFR can be ordered at http://www.usfa.dhs.gov/applications/publications/.
Always remember that as a first responder to a hazardous materials emergency, your initial actions on scene can set the stage for the entire incident. Although a hazardous materials team may be called to the scene with sophisticated equipment and extensive training, the decisions of personnel who first arrive on engines, ladder trucks, and ambulances (not to mention police officers) regarding initial isolation and evacuation areas, scene control, and care for those who are injured must be correct in order to protect the public and ensure your survival.
Making correct decisions is not based on your experience alone, but also your ability and diligence to thoroughly size up the incident, ask the right questions, and gather useful information from appropriate reference sources. Correct decisions are by default informed decisions and those which allow a defense should your actions be scrutinized by others. Remember that taking action is the easy part. Explaining your actions later on, especially if things don’t go well, is usually a lot harder.
The Scenario
On December 18 at 3:07 p.m., your engine is dispatched to a report of a liquid leaking from the back doors of a tractor trailer parked at an interstate rest area. The temperature is 38 degrees F. The incident has been reported by a trucker who noticed the spill while driving past the leaking trailer.
While en route, you learn that a police unit has arrived on scene only to find the driver at the rear of the trailer attempting to remove the plastic tamper seal and open the doors. The driver’s hands reportedly have contacted some of the spilled material.
The police officer orders the driver to move away from the vehicle and to go inside the rest area to wash his hands. The officer then reports that the trailer displays a white placard that contains “6” as the Hazard Class Number and the words “Inhalation Hazard.” The four-digit ID number 1163 is also displayed. Your dispatcher relays this information to you.
Your estimated time of arrival is now about two minutes and the officer is asking what he should do. Using the ERG2004 from your engine, what guide would you refer to and what advice would you provide to the police officer regarding the following actions –
1. Using the ERG2004 from your engine, what guide would you refer to?
Using the ERG2004 index that lists four-digit ID numbers in numerical order (yellow-bordered pages), entries for the four-digit number 1163 refer the user to Guide 131 of the orange-bordered-pages. Take note that each entry for this four-digit ID number is highlighted.
2. What advice would you provide to the police officer regarding the distance for an initial isolation area?
According to the ERG2004, the initial isolation distance is 200 feet in all directions. This information is available in the Table of Initial Isolation and Protective Action distances (green-bordered pages). While Guide 131 indicates an initial isolation distance of 150 feet in all directions, remember that on page 96 of the ERG2004, it states that, “If an entry is highlighted in either the yellow-bordered or blue bordered pages (as are the entries for the four-digit ID number of 1163), and there is no fire (there is no fire involved with this scenario at the time), go directly to the Table of Initial Isolation and Protective Action Distances and look up the ID number and name of the material to obtain initial isolation and protective actions distances.” Although the Table of Initial Isolation and Protective Action distances includes an initial isolation distance of 100 feet, remember that this is for a “small spill” (from a small package or small leak from a large package) while the initial isolation distance of 200 feet suggested there is for “large spills” (from a large package or from many small packages). On page 300 of the ERG2004, it states that a small spill is one “which involves a single, small package, such as a drum containing up to approximately 200 liters (about 50 gallons), a small cylinder, or small leak from a large package.” Not knowing the exact type or number of containers in the trailer during the early stages of the incident, the best course of action is to prepare for a worst case scenario and use the larger initial isolation distance of 200 feet.
3, What advice would you provide to the police officer regarding a means to isolate the area. Is it OK to use flares? (Remember the placard displayed)
The use of road flares is not recommended as a means to isolate the area. According to Guide 131, the material is “Highly Flammable,” and “will be easily ignited by heat, sparks, or flames.” It also states that “most vapors are heavier than air” and that “vapors may travel to source of ignition and flash back,” and provides a caution to “eliminate all ignition sources.” It is important to note that the placards displayed on the transport vehicle indicate the presence of a poisonous substance (Hazard Class 6), which could lead first responders to assume that there is no flammability hazard. However, remember that in the Code of Federal Regulations (CFR) governing transportation, 49 CFR 171.8 defines a hazard class as “the category of hazard assigned to a hazardous material.” It further states that “A material may meet the defining criteria for more than one hazard class, but is assigned to only one hazard class.” This is done using a predetermined criterion known as the Precedence of Hazard Table found in 49 CFR 173.2(a). Therefore, although this material is placarded as a poisonous inhalation hazard, it also possesses flammable characteristics that first responders must take into consideration when making decisions that will ultimately affect their safety.
When you arrive on scene, you use binoculars to observe a steady stream of a clear liquid from the rear of the trailer that has already formed a pool approximately six feet in diameter. You also notice a storm drain approximately 400 feet from the spill site and determine that the liquid appears to be moving in that direction.
The driver has returned after washing his hands for a few minutes and he informs you that the trailer is loaded with 50 drums, each with a capacity of 58 gallons. The drums are single stacked and had been blocked and braced by the shipper. However, the driver admits that he was forced to apply the vehicle brakes hard about five miles before entering the rest area to avoid a hazard in the roadway and that this action may have caused the load to shift. You do not allow the driver to enter his tractor to retrieve the shipping papers because of your already-established initial isolation area.
Your battalion chief arrives on scene. His vehicle is equipped with a laptop computer that has Internet access. He decides to access the NIOSH Web site at http://www.cdc.gov/niosh/npg/ and obtain additional information using the NPG. He also has a CR-ROM version of the HMGFR. Since only the four-digit ID number is available at this time, when using the NPG, he enters this number after selecting “Search the Pocket Guide.” For the HMGFR, he refers to the UN/NA Number Index.
4. The ERG2004 lists two products that are assigned the four-digit ID number of 1163. Identify each of the possible products involved. Are these two separate products or are the names synonymous, meaning that each name refers to the same material? How can you confirm the results of your research?
Both the NIOSH NPG and the HMGFR state that other names for 1,1-Dimethylhydrazine are Unsymmetrical Dimethylhydrazine or Dimethylhydrazine, unsymmetrical.
5. The likelihood is that several of the drums on the trailer may have been damaged. Recognizing the severe potential of the incident, the battalion chief decides to initiate protective actions. What distances should be given consideration?
Recalling from an earlier response that first responders should assume the worst case scenario and prepare for a “large spill,” the ERG2004 suggests a protective action distance of 0.8 miles downwind for this material. When making this decision, remember that in addition to the size of the spill, first responders also need to consider the time of day. On page 299 of the ERG2004, it states “since atmospheric mixing is less effective at dispersing vapor plumes during nighttime, day and night were separated in the analysis.” It further states that “day refers to time periods after sunrise and before sunset, while night includes all hours between sunset and sunrise.” While this incident occurred shortly after 3:00 p.m. during December, which is before sunset, the likelihood is that the incident will extend beyond sunset (which likely will occur by 6:00 p.m. in most areas) and as a result, first responders should begin preparing to use the larger protective action distance. The distance used is for incidents that involve “large spills that occur at night,” which is greater than the protective action distance of 0.4 miles, which would be used for daytime incidents.
6. What are the “degrees of Health, Flammability, and Instability hazards” according to the National Fire Protection Association 704, Standard System for the Identification of the Hazards of Materials for Emergency Response?
According to the HMGFR, the degree of each hazard is as follows:
Health = Four
Fire = Three
Instability = One
Remember that the numerical ratings range from four, indicating a severe hazard, to zero, indicating a minimal hazard.
7. What can be used to dike the area around the storm drain? Do you have these available at the scene? If not, what is the procedure in your department to request these items?
According to the ERG2004 (Guide 131), earth, sand, or other noncombustible material can be used. Furthermore, the HMGFR states that first responders should attempt to prevent material and runoff from entering sewers and waterways, but only “if it can be done safely well ahead of the release.” While earth and sand may be available at the scene from nonpaved areas, first responders may be able to request that sand or soil be transported to the scene by their local or state government public works departments or by a private contractor. Always remember that first responders need a way to contact these representatives outside of normal working hours and that some consideration should be given to who will pay for the materials that are delivered to the scene. Also, any attempt to dig up large amounts of soil or sand from unpaved areas must always take into consideration the presence of underground utilities. This is especially important whenever mechanical equipment, such as a backhoe, is used to accomplish this task. You should therefore know how to contact the utility locating service in your area. Most will provide immediate assistance to locate utilities during an emergency rather than require first responders to wait during a 48-hour notification period that is often the standard for construction contractors.
8. You determine that the storm drain leads to a small flowing stream behind the rest area. In the event that a dike built around the storm drain is unsuccessful in preventing migration of the product (or if you decide not to build one) one of your crew members suggests use of an underflow dam to contain any material that may enter the stream. Would this be an effective course of action?
An underflow dam is a containment device built using pipe (such as a piece of PVC pipe or even a section of hard sleeve hose from fire apparatus) inserted through an earthen dam wall that then allows clean water to flow through the pipe while the dam contains those hazardous materials that float on water. While the ERG2004 states that many liquids assigned to Guide 131 are “lighter than water,” which would lead some to believe that an underflow dam would be useful, both the NIOSH NPG and the HMGFR state that the material will mix with water, which would thereby reduce the effectiveness of an underflow dam.
9. In addition to contamination of the flowing stream, are there any other potential problems that could occur if the material enters the storm drain? What other safety concerns could exist if the material entered the water?
According to the ERG 2004, runoff to sewers may create a fire or explosion hazard. Additional safety concerns include contamination of the flowing stream and any other waterways that are fed by this body of water. The contamination could harm fish as well as any animals that may drink the water, requiring notification of local and state agencies responsible for environmental protection. Although incidents such as this may not present an immediate health hazard to humans, since outdoor recreational activities involving water are limited during winter months, there is still a possibility that the water could ultimately reach intakes for industry or treatment plants that prepare water for domestic use. Remember that the HMGFR states that first responders should “notify local health and fire officials and pollution control agencies,” and that “if a material or contaminated runoff enters waterways, notify downstream users of potentially contaminated water.”
10. Should you be concerned about controlling ignition sources? (*)
What is the material’s flashpoint? 5°F
What is the Lower Explosive Limit (LEL)? 2%
What is the Upper Explosive Limit (UEL)? 95%
What is the Flammable Range? 2% – 95%
Is the Flammable Range a cause for concern?
There is a wide flammable range that could present a serious risk of fire or explosion to those on scene, especially to members of a hazardous materials response team who may enter the trailer in an attempt to stop the release.
Are the vapors heavier or lighter than air? What difference can this make?
According to the HMGFR, vapors from this material are heavier than air and they will collect and stay in low areas. This characteristic makes these vapors less likely to disperse into the atmosphere where their concentration can then be diluted with air. Heavier-than-air vapors also influence the way in which atmospheric monitors are used, since casually holding the device at waist level (as is often done with atmospheric monitors) may not provide first responders with the opportunity to detect this material.
(*) All responses are based upon the NIOSH NPG.
11. The four-gas atmospheric monitor on your engine includes a combustible gas indicator. If you attempt to measure the concentration of vapors produced by the material, will the readings provided by the atmospheric monitor be an accurate reflection of the vapor concentration or would an adjustment to the readings obtained be necessary?
The sensitivity of combustible gas sensors varies with exposure to different types of atmospheres. Thus any attempt to measure the concentration of gases other than that used during calibration of the device will result in a reading that is likely greater or less than the actual concentration. Many combustible gas indicators are calibrated using gases such as methane or pentane and as such will be accurate only when reading the calibration gas. Remedying this situation will require the use of a “correction factor” or “relative response curve” specific to the gas or vapor measured in order to obtain more accurate results. The manufacturer of an atmospheric monitor is usually the best source for information related to the appropriate correction factors or relative response curves that should be used.
12. What types of products are incompatible with the material involved in this incident? What type of reactions could be expected if certain types of incompatible materials were also involved?
According to the NIOSH NPG, incompatible materials include oxidizers, halogens, metallic mercury, fuming nitric acid, and hydrogen peroxide. This document also states that the material may ignite spontaneously in contact with oxidizers. The HMGFR states that the material is corrosive to plastics. First responders should always be aware of incompatibilities when dealing with hazardous materials and assess the incident scene to determine if any of the incompatible items are at risk for contacting the materials involved. The likelihood of exposure to incompatible materials is especially of concern when dealing with incidents that occur in warehouses, retail establishments, or in delivery vehicles that contain multiple shipments.
13. If the spilled material were to ignite, what are the recommended extinguishing agents? Do you have these available at the scene? If not, are they available locally and what is the procedure in your department to request these items?
According to the ERG2004 and the HMGFR, recommended extinguishing agents include dry chemical, CO2, water spray, or alcohol-resistant foam. Although most departments have access to varying amounts of dry chemical, CO2, and regular foam (intended for use on fires involving hydrocarbon fuels such as gasoline and fuel oil) there may be limited supplies of alcohol-resistant foam available. In this situation, preplanning is critical to determine in advance those fire departments from surrounding localities that may have alcohol-resistant foam and to develop the necessary legal agreements that allow for an immediate transfer of this material during an emergency. Remember that the effectiveness of a plan such as this can be severely reduced or eliminated when it requires someone to ask permission in order to release the needed resource and the person they need to contact is unavailable during the height of an incident. Always have a “Plan B.” Remember, too, that there may be commercial vendors who can deliver firefighting foam to the scene. However, some of them may not be willing to provide supplies to first responders, even those intended for immediate use during emergencies, unless there is some assurance they will get paid. Decide in advance what you would do if confronted with this problem.
14. What preparations could you make in anticipation of a fire involving the spilled material and perhaps the vehicle?
Although first responders should make every effort to eliminate ignition sources, a fire is still a potential that should be anticipated. According to both the ERG2004 and the HMGFR, a fire involving a trailer load of this material should be fought from a maximum distance or through use of unmanned hose holders or monitor nozzles. During the incident, first responders could begin setting up these nozzles and making preparations for water supplies capable of delivering large quantities of water for an extended period of time. Remember that incidents occurring on interstate routes (including rest areas) may offer limited access to hydrants, so that water supply shuttles may be necessary.
15. The battalion chief asks if a “polymerization hazard” exists with this material. What is your response?
The ERG2004 defines polymerization as a “chemical reaction which is generally associated with the production of plastic substances. Basically, the individual molecules of the chemical react with each other to produce what can be described as a long chain.” On page 2 of the ERG2004, it states that, “The letter ‘P’ following the guide number in the yellow-bordered and blue-bordered pages identifies those materials which present a polymerization hazard under certain conditions.” According to the ERG2004, entries for the four-digit ID number 1163 do not include the letter “P” and therefore there is no polymerization hazard suspected with the material.
16. The truck driver claims that he completely washed the material from his hands. Should you still be concerned about his well-being? If so, why? Should you be concerned about the section of the rest area where he washed his hands? Is so, why and what actions would you take, if any?
According to Guide 131 from the ERG2004, this material may be fatal if inhaled, ingested, or absorbed through the skin. The driver may therefore still be in danger as a result of exposure, despite having washed his hands for a “few minutes,” since the Guide states that material should be flushed from skin with running water for “at least 20 minutes.” It is also likely that the driver inhaled some of the material in addition to his skin exposure. Although this individual may initially deny the need for medical treatment, first responders should take note of precautions from Guide 131 which state that the effects of exposure (including inhalation, ingestion, or skin contact) could be delayed. This information should be made available to the driver if he insists on signing a “patient refusal” statement. Furthermore, the rest area buildings could now be contaminated as a result of the driver’s presence there earlier. In addition to possible contamination of the washroom area, the driver could have contaminated the floors from material that contacted his shoes while he was standing at the rear of the trailer. Therefore, the rest area buildings should be isolated and responsibility to reopen the facility should be placed on the property owner, which is most likely state government. At the conclusion of the incident, government officials would likely hire a commercial contractor to clean any affected areas and to determine when it would be safe to reopen. First responders should refrain from assuming liability by attempting to clean up the rest area themselves.
17. You have determined that it is too dangerous to allow anyone to approach the vehicle to obtain the shipping papers. How could you obtain a duplicate set of these documents?
For larger trucking companies, contact with a dispatcher from that company should enable first responders to locate a duplicate set of shipping papers. For incidents that involve smaller companies, or perhaps one that involves an independent driver who owns and operates his own truck, first responders may be able to contact a shipping broker (a company that arranged the shipment) or perhaps even the shipper themselves in an attempt to obtain a duplicate set of shipping papers. The driver should be able to provide contact information for dispatchers, brokers, or shippers. If a telephone number for the shipper or broker is not immediately available from the driver, he should at least know the name and location of the point of origin. This will enable first responders to then locate a telephone number for the shipper through directory assistance. However, remember that a telephone number obtained in this manner may not be answered outside of normal business hours. When this occurs, first responders can contact the local emergency dispatch center for the city or town where the shipper is located and request if they have an after-hours contact for them.
18. How could you obtain a Material Safety Data Sheet while on scene?
As a general rule, Material Safety Data Sheets (MSDS) for a chemical are available from the manufacturer of the product with the intent of providing information about the material to those who will use it. First responders on-scene at a transportation incident involving hazardous materials will rarely find that MSDS will accompany shipping papers. However, MSDS can still provide first responders with valuable information, and unlike the ERG2004, the information from a MSDS is specific to that chemical. To obtain an MSDS, first responders should remember that according to 49 CFRR 172.604(a), shipments for regulated hazardous materials must include an “emergency telephone number” where first responders can contact someone who “has comprehensive emergency response and incident mitigation information for that material.” This information should include access to a MSDS. Quite often, the number provided is that of the Chemical Transportation Emergency Center (CHEMTREC) and when this occurs, Emergency Service Specialists at CHEMTREC will be able to provide first responders with the required MSDS either via fax or on some occasions, via e-mail.
19. Who could you contact for information about the health effects of the material?
Information on the health effects of a material are best obtained from the manufacturer of the product. Most likely they have had numerous requests for this information in the past and as such have compiled data specific to these concerns. Other sources of information include local poison control centers as well as CHEMTREC.
20. Should you be concerned about the weather? What hazard, if any does the current outdoor temperature present to first responders?
The weather should be a concern to first responders. Although a temperature of 38°F is cold, there is a likelihood that temperatures could drop to below freezing after sunset, thus presenting an increased potential for injuries from hypothermia and those occurring as a result of slips and falls on ice. Knowing this, first responders should make plans to provide shelter to personnel on-site. Although some departments may have a “command post” vehicle that can offer shelter to a limited number of persons, or various types of portable shelters that can be brought to the scene, even a school bus can also provide for a warm place of refuge during winter incidents. Local or state government public works departments should be able to provide sand that can be spread mechanically on ice to reduce slip and fall hazards.
21. This incident likely will require several hours to resolve. How could you obtain an accurate weather forecast for the next 12 to 24 hours?
First responders should know how to contact representatives from the local office of the National Weather Service. In some cases, a listing of telephone numbers for this office may be found along with those for other federal government agencies under the heading of “Weather” or the “National Oceanic and Atmospheric Administration.” Contacts with meteorologists from local news stations may also prove to be an effective source of information. Remember that because of the long-term nature of many hazardous materials incidents, extended forecasts are essential. Remember also to obtain updates to weather forecasts on a frequent basis.
22. If it were to rain, how would this impact your efforts to contain the spilled material? Will the spilled material react with rain?
Although there is no indication from any of the reference sources used that this material will react with water, rain may destroy any barriers built to contain spilled materials or those built to prevent passage of material into storm drains. First responders should therefore anticipate the path of travel for storm water runoff (that would likely be contaminated with the material) and notify those who may be affected by the migration of the material from the incident scene. As stated earlier, these notifications should include local and state agencies responsible for environmental protection. First responders on-scene should also ensure that they are not impacted by storm water runoff based upon the location of functions such as the command post and equipment staging areas. Staying uphill of a release of hazardous materials is especially important during rain events, even if there is only a slight grade to the terrain.
Click here for more info on Steven De Lisi’s book, Hazardous Materials Incidents: Surviving the Initial Response.
Steven M. De Lisi is a 27-year veteran of the fire service and is Deputy Chief for the Virginia Air National Guard Fire Rescue, located at the Richmond International Airport. De Lisi is a Hazardous Materials Specialist and a former chairman of the Virginia Fire Chiefs Association’s Hazardous Materials Committee. He is also an adjunct instructor for the Virginia Department of Fire Programs and a former member of the NFPA committee on hazardous materials protective clothing. De Lisi began his career in hazardous materials response in 1982 as a member of the HAZMAT team with the Newport News (VA) Fire Department. Since then, he has also served as a Hazardous Materials Officer for the Virginia Department of Emergency Management and in that capacity provided on-scene assistance to first responders involved with hazardous materials incidents in an area that included more than 20 local jurisdictions.
