Protective Clothing for Hazardous Material Emergencies
PROTECTIVE CLOTHING
No one type of protective clothing will satisfy every condition. Selecting the level of personal protective equipment necessary for the incident at hand is the key to a safe, effective hazardous material operation.
The objective of emergency response personnel at hazardous material incidents is to create a more favorable outcome. Inherent in achieving this objective is the need for safe operations, particularly in regards to the selection and use of protective clothing.
My objective is to introduce a decision matrix to assist responders in evaluating response procedures and selecting the proper level of personal protection for use at hazardous material emergencies. The information provided in this decision tree is designed to be applied as a training tool rather than a response-oriented guide.
Is a hazardous material present? Can you specifically identify the product?
Determining if a hazardous material is present and identifying the product are the keystones of all decision making. If responders are not aware that a hazardous materials problem exists, the development of the appropriate strategies and tactics will be quite difficult. Situations have occurred where response personnel have been involved in an operation for some time before it was determined that hazardous materials were involved. For example, several structural fires have been found to contain agricultural chemicals only after a number of firefighters have collapsed or suffered from “apparent” smoke inhalation.
There are six basic clues for recognizing and identifying hazardous materials:
- Occupancy and location
- Container shapes
- Markings and colors
- Placards and labels
- Shipping papers and documents
- Senses
Although the certainty of positive identification increases as one gets closer to the incident site (e.g., occupancy/location vs. shipping papers), the level of risk to response personnel also increases. It is important that the specific chemical(s) involved be determined. This includes the proper shipping or chemical name and the correct spelling. Experience has shown, however, that it is not always possible to specifically identify the materials involved in the initial stages of the emergency. The only clues for possibly identifying the hazardous materials class may be a placard or a container shape. Response personnel should be able to identify hazard classes (e.g., poison, oxidizer, flammable, etc.) by placard/label color, hazard symbol, and the United Nations class number.
Personal Protection Level—Decision Matrix
If the materials involved cannot be specifically identified, it is essential that an effective site management policy be established. The purpose of this policy is to establish perimeters; maintain safe and efficient control over operating personnel; and prevent personnel, vehicles, and equipment from accidentally entering a contaminated area. All personnel should avoid direct exposure to the hazardous material involved (i.e., don’t give it the Pepsi taste test!). A minimum of Level I protection should be worn in the perimeter area.
Can the potential harm be estimated?
Once the materials have been identified, determine the hazards involved. The incident commander should attempt to anticipate the likely behavior of the hazardous material and its container, and the harm associated with that behavior. This way, the incident commander can more accurately define the problem at hand.
If the potential harm cannot be quickly estimated, direct exposure to the hazardous material must be avoided. Emphasis should be on isolating the area and denying personnel entry. Both the incident commander and the safety officer must ensure the safe, effective control of the site. This can often be accomplished by the development of control zones (hot, warm, and cold) for managing the incident site. Banner guard tape, color-coded traffic cones, special signs, and natural and man-made barriers can be used to define these areas.
Proper protection creates a more favorable outcome at haz-mat incidents.
Secondary informational sources, such as reference guides, CHEMTREC, or facility personnel, can be consulted to determine the specific identity and the hazards of the materials involved. Remember, however, that there are no hazardous materials experts, only informational sources. The incident commander must be aware of both the advantages and the limitations of all informational sources used.
With the release of the Occupational Safety and Health Administration (OSHA) Hazard Communication Standard, as well as the promulgation of Right-to-Know legislation at both the state and local levels, the use of material safety data sheets (MSDS) is also becoming more common. These documents can provide a great deal of hazard and response information for incidents at fixed facilities. Information provided includes:
- Both the chemical and common name of each product containing more than 1% of a hazardous ingredient, and all carcinogens greater than 0.1%.
- The physical and chemical properties of the substance.
- The physical hazards (fire, explosion, reactivity).
- The known acute and chronic health effects, including the signs and symptoms of exposure.
- Recommended personal protective clothing and equipment.
- Procedures for handling spills, leaks, or fires with the substance.
Identify the harmful events
Hazardous materials must be evaluated for their ability to produce harm. Emergency response personnel can be adversely affected by any of six events. These harmful events can be found alone or with each other.
• Thermal. Thermal refers to those events that are related to temperature extremes. For example, high temperature extremes are common to such emergencies as flammable liquid spill fires, flammable gas fires, and structural fires. The structural firefighting clothing currently in use is designed primarily for protection against fire and heat. Most encapsulated suits will not withstand exposure to high temperatures.
Exposure to low temperatures found with liquefied gases and cryogenic materials can result in thermal harm through frostbite. If the duration of exposure is limited, a firefighter’s protective clothing may be effective. However, some encapsulated suits may become brittle and crack when exposed to extremely low temperatures.
- Radiation. Radiation is the waves or particles of energy that are emitted from radioactive sources. Depending upon the intensity of the source material, the energy released may be in the form of alpha or beta particles, or gamma rays. The level of personal protection required will vary with the intensity of the source material.
- Asphyxiation. Many materials have the ability to displace oxygen when released in a confined environment, such as carbon dioxide or nitrogen. Exposure to high concentrations of such materials as chlorine and anhydrous ammonia can be fatal almost immediately. Asphyxiation also can occur when chemicals interfere with the respiratory process. For example, carbon monoxide reduces the ability of the blood to transport oxygen, while cyanide exposure prevents oxygen from being absorbed into body tissue.
- Chemical. The body can be affected through chemical mechanisms/ reactions. For example, exposure to a corrosive such as nitric acid can cause severe and deep tissue burns to the skin or permanent eye damage. When working in corrosive atmospheres, specialized protective clothing is required. Other materials, when introduced into the body, may cause bone destruction (hydrofluoric acid), internal burns (anhydrous ammonia), and nervous system failure (parathion).
- Etiologic. Etiologic events can be created by uncontrolled exposure to living micro-organisms. Diseases commonly associated with such exposure include hepatitis, typhoid, and cancer. Major problems with etiological exposures include the inability to detect when and where the physical exposure occurred and the routes of entry into the body.
- Mechanical. Examples of mechanical harm include the scattering of fragments as a result of an explosion, shock waves, and impact forces. Protective clothing will not offer a high level of protection from exposure to
Photo by John Hess
- mechanically harmful events.
Determine response objectives and strategies
The goal of emergency response personnel at a hazardous material incident is to favorably change or influence the outcome. Every emergency will follow a natural sequence of events that will result in a natural outcome. Natural outcomes are measured in terms of:
- Fatalities
- Incapacitating injuries
- Property damage
- Critical systems disruption
- Environmental damage
In evaluating objectives/strategies, the incident commander must ensure that the course of action selected will result in an outcome that is “more favorable” than a natural outcome with no intervention. If no harm has occurred prior to the arrival of response personnel, the incident commander must evaluate the need and risk of involvement.
Common response objectives include:
- Rescue of injured and removal/ evacuation of endangered persons
- Prevent container breach or failure
- Product control and confinement
- Extinguishment of ignited materials
- Exposure protection
Based upon the assessment of the materials involved, their relative hazards, and the response objectives, the necessary protective clothing and equipment should be selected.
Determine level of personal protection required
No one type of protective clothing will satisfy the need for personal protection under all conditions. Four levels of personal protective clothing are available for use at hazardous material emergencies:
- Level I—Structural firefighting clothing
- Level II—Non-encapsulated protective clothing
- Level III—Encapsulated protective clothing
- Level IV—High temperature specialized protective clothing
The author notes that this system is not meant to replace the levels of personnel protection (A, B, C, D) used by the U.S. Environmental Protection Agency (EPA). The four-level system discussed herein specifically relates to the protective clothing needs of firefighters, and builds on the structural firefighting gear used daily in the fire service. It also recognizes that firefighters will be using self-contained breathing apparatus (SCBA) as the minimum level of respiratory protection in the initial stages of the emergency.
Level I—structural firefighting protective clothing. Full protective clothing for use at hazardous materials emergencies is NOT the same as full protective clothing used in structural firefighting. To effectively communicate that difference and minimize confusion, full protective clothing as applied at hazardous material emergencies will be referred to as Level I protection.
According to the National Fire Protection Association’s Code 49, Hazardous Chemicals Data, full protective clothing is “protection to prevent gases, vapors, liquids, and solids from coming in contact with the skin. [This] includes the helmet; [positive pressure] self-contained breathing apparatus; [turnout or bunker] coat and pants …; rubber boots; gloves; bands around legs, arms and waist; and face mask; as well as covering for the neck, ears and other parts of the head not protected by the helmet, breathing apparatus or face mask.” This definition takes into account more protection than normally considered “full” by firefighters, and a great deal more than that normally provided for Emergency Medical Technicians or paramedics.
Level 1 protection can be used if the following conditions are met:
- Unlikely contact with splashes of extremely hazardous materials.
- Total atmospheric concentrations do not contain high levels of chemicals toxic to the skin.
- There are no adverse effects of chemical exposure to small areas of unprotected skin.
The use of bunker pants will afford appreciably more protection than that offered by -length boots. Nomex hoods can be used to cover all exposed skin in the head area. Duct tape is then used to completely seal all openings. For discharges and spills of moisture-seeking chemicals, such as chlorine or anhydrous ammonia, petroleum jelly can be used to provide additional protection to the moist areas of the skin. By copiously applying the petroleum jelly under the arms, around the neck, and in the groin and buttocks area, it is possible to alleviate the discomfort of potential burns.
Gloves must be selected in relation to the materials being encountered. For maximum safety, two sets of gloves (inner and outer gloves) should always be used. Cotton, synthetic fiber, and leather gloves will absorb liquids and create problems of skin absorption when working around many poisons and agricultural chemicals. Additionally, they will deteriorate when exposed to corrosive liquids. Synthetic rubber and plastic gloves may deteriorate on contact with certain petrochemical products. Also, they may not provide adequate protection against some corrosives and agricultural chemicals. When dealing with agricultural chemical incidents, protective clothing compatability information can be acquired from the container label.
Products that penetrate natural rubber, such as methyl bromide and dichloropropene, can create exposure problems with firefighting gloves, boots, and facepieces. With some chemicals, the use of neoprene or polyethylene-constructed protection may be specified. This can be done by using neoprene or polyethylene gloves and booties under your firefighting gloves and boots. Polyethylene gloves and booties are commonly used at cafeterias and meat markets, and are fairly easy to acquire. If necessary, polyethylene bread bags or dry cleaning bags can also be used.
Level II —nonencapsulated protective clothing. Situations can occur where Level I protection will not provide an adequate level of personal protection. The hazards and potential harm of the released material may require that specialized protective clothing be worn. NFPA 49, Hazardous Chemicals Data, defines special protective clothing as “clothing specifically designed to protect against a specific hazard.” Nonencapsulated protective clothing. Level II protection, is specialized clothing. It does not offer the level of protection that single encapsulation provides.
Nonencapsulated protective clothing is effective against exposures to radiation (alpha and beta rays), chemicals, and etiological harm where total skin protection is not necessary. This clothing is often used in industrial applications involving agricultural chemicals and pesticides, mild corrosives, asbestos fibers, lead dust, and polychlorinated biphenyls (PCB). Level II protection is generally not used in the initial stages of an emergency. This clothing is used after the hazards and the necessary protection have been evaluated by qualified individuals (industrial hygienists, etc.).
To handle such diverse applications, a variety of different clothing materials are available. Common suit materials include neoprene, butyl rubber, Nomex, polyvinyl chloride (PVC), chlorinated polyethylene (chloropel), and Tyvek. The selection of the protective clothing material must be based upon the objectives to be accomplished, the potential hazards, and chemical compatability.
The most common types of non-encapsulated protective clothing are single-piece coveralls and two-piece bib overalls or pants worn in conjunction with a jacket. A hood can be attached to the suit or worn separately. The use of a hard hat or helmet is recommended. Gloves should be selected according to the chemicals being handled. Because of material absorption, the use of leather or suede/Kynol gloves should be discouraged. Although boots should also be selected according to the hazard, shoe covers constructed of a variety of materials are available. Duct tape is recommended to seal all openings and exposed areas.
Air purifying respirators are often used with Level II protection during clean-up or remedial operations. However, positive-pressure SCBA should always be used until a qualified individual (e.g., industrial hygienist) determines that the level of respiratory protection can be downgraded.
Level III —encapsulated protective clothing. Encapsulated suits are specialized protective clothing that, when used with air-supplied respiratory protection devices, offers full-body protection from a hostile chemical environment. In contrast to the nonsealing features of Level II protection, encapsulated suits offer a sealed, integral level of protection.
Criteria for using Level III protection include:
- Extremely hazardous substances are known or suspected to be present and skin contact is possible (e.g., cyanide compounds, toxic and infectious substances).
- Potential contact with substances that destroy skin (e.g., corrosives).
- Operations involving a high potential for splash or exposure to unexpected vapors, gases, or particulates.
- Operations involving unknown or
- unidentified substances and requiring the intervention of emergency response personnel.
Common suit materials include butyl rubber, PVC, Viton, and chlorinated polyethylene (chloropel). In addition, disposable encapsulated suits constructed of Tyvek, Saran, and polyethylene-coated Tyvek and PVC are available. Users must recognize that no single material is compatible with all chemicals. For example, of the 985 chemicals listed in the CHEMICAL HAZARDS RESPONSE INFORMATION SYSTEM (CHRIS) manual, butyl rubber is compatible with approximately 70%.
Respiratory protection can be provided to encapsulated suits by several methods. The most common method is the use of a positive pressure SCBA worn underneath the suit. Other methods include the SCBA worn outside of the suit, and the application of airline hose units. Airline hose units require the use of an emergency escape pack or an SCBA as a secondary source of air supply.
Encapsulated suits are specialized protective clothing with definite limitations. The need for an effective training program, both classroom and practical, cannot be over-emphasized. Operations in encapsulated suits subject the user to a great deal of physical and mental stress. Marty fire department response teams limit individuals to a maximum of 30 minutes in these suits. In addition, many firefighters who are excellent structural firefighters have experienced severe difficulties when operating in encapsulated suits.
Level IV —high temperature specialized protective clothing. High temperature specialized protective clothing is used in situations where response personnel must operate in high heat environments that exceed the protection factors of structural firefighting clothing. Examples include aircraft firefighting and large flammable liquid and gas emergencies.
Three types of aluminized protective clothing ensembles are commonly used. Each type is applicable to a specific thermal environment.
- Approach suits are used in applications where radiant heat exposures of up to 2,000°F are reached for brief periods of time (approximately three minutes or less). These suits are often used in steel mills and other industrial environments that have high temperatures.
- Proximity suits are designed for short duration, close proximity exposures to flame and radiant heat temperatures as great as 1,500°F. In addition, they will withstand exposures to steam, liquids, and weak chemicals. These suits consist of three to six layers of material with an outer shell of aluminized glass or asbestos fabric. The inner layers consist of two to four layers of insulating materials. Proximity suits typically are used by airport firefighting crews for personal protection.
- Fire entry suits offer complete and effective protection for short duration entry into total flame environments. They are designed to withstand prolonged exposures to radiant heat levels up to 2,000°F. Entry suits are commonly used in chemical plants and refineries where flammable liquids, gases, and other materials are refined or processed. Rescue operations using these suits are limited because of the extended time factor in donning the suit and preparing to enter the fire area.
Is the required level of protection available/adequate?
Although hazardous material emergencies are a potential threat to all communities, the rate of incidence is much less than that of structural fires. As a result, many fire departments do not have specialized Level II, III and IV protective clothing immediately available for emergency operations. In response to this problem, effective fire department managers have wisely used mutual aid and regional response teams. These teams can provide the necessary specialized equipment and expertise for responding to hazardous incidents.
In evaluating strategies, the incident commander must consider any possible time delays until specialized clothing, equipment, and personnel become available. If the delay is excessive, alternative strategies may have to be examined. For example, delays of two to six hours are common in many areas of the country until environmental or other specialized personnel can arrive on the scene.
Feedback and evaluation are an inherent aspect in successfully managing the emergency. The effectiveness and reliability of the level of personal protection used must be closely monitored by the safety officer. If the protective clothing is not offering adequate protection, it will be necessary to either select a higher level of personal protection (Level II vs. Level III) or to reevaluate current response objectives.
Summary
The selection of personal protective clothing is a key element in bringing a hazardous materials emergency to a safe, favorable outcome. The protective clothing decision tree is designed as a training tool to assist fire instructors and company officers in discussing the application of protective clothing at hazardous material incidents.