CPC is designed to shield the wearer from skin contamination and airway exposure. The garment prevents skin contact with the toxic agent and the respirator protects parts of the face and airway from inhaled hazardous vapor or harmful particles. There is a wide selection of PPE available with varying protection levels, styles, sizes, types of construction, comfort levels, and ease of use. The incident commander or purchasing entity should choose an ensemble that will protect the wearer in the most reasonably foreseen emergency.
Chemical Protective Clothing
The purpose of CPC is to shield or isolate an individual from the chemical, physical, and biological hazards that may be encountered in a hazardous materials incident. During chemical operations it is not always apparent when exposure occurs. Many chemicals pose invisible hazards and offer no warning signs. As a result, appropriate procedures must be followed and protective clothing must be worn whenever the wearer faces the potential of being exposed to a hazardous agent. This includes the response phase of a hazardous materials incident, victim triage, decontamination, site cleanup, and waste disposal.1,12
CPC is part of a PPE ensemble that may include other equipment items such as inner and outer gloves, boots, and eye protection. These items must be easily integrated with the CPC to provide both an appropriate level of protection and allow the wearer to carry out various activities demanded in the response. In addition, the ensemble may require the deployment of a cooling system when working in hot, humid weather, or a communications device. Each of these ensemble components must support the mission of the wearer and not interfere with mobility, dexterity, vision, or donning requirements.1
For hazardous substances, the protective clothing ensemble typically includes a chemical resistant, multi-layered coverall type suit, two layers of gloves, and boots or flexible overboots to go over shoes. No single material protects against all chemicals, combinations of chemicals, or against prolonged exposure, so a multi-layered garment composed of different materials should be considered. The choice of composite materials should provide protection against a variety of known chemicals stored, used, or transported in the community as well as offering the broadest chemical resistance against the widest range of unknown chemicals. The material(s) selected must also resist degradation, permeation, and penetration by the respective chemicals.1
Degradation involves physical changes in a material that occur through direct contact with chemical substances, use of the garment, or ambient conditions (e.g. sunlight). Such contact may cause the suit’s material to crack, become brittle, discolor, or deteriorate.
Permeation is a process in which a chemical diffuses or dissolves through a garment’s material on a molecular basis. The rate of diffusion varies depending on the chemical concentration; material composition and thickness; and the humidity, temperature, and pressure of the surrounding environment. Most material testing is done with 100% pure chemical over an extended exposure period. The time it takes the chemical to permeate through the garment material is the breakthrough time. An acceptable material is one where the breakthrough time exceeds the expected period of garment use. It is required that the suit’s manufacturer provide information on a suit’s permeation or breakthrough time.
Penetration is the movement of chemicals through an opening in the suit, specifically at seams or zippers, and from faulty manufacturing.
The selected protective ensemble should be comfortable to wear while allowing the user to perform vital tasks. It must: 1) be economical; 2) decontaminate easily (disposal should also be simple); 3) comply with regulatory standards; and 4) possess key physical properties such as functionality in extreme environmental conditions and strength (resist physical hazards, tears, and weather extremes). A series of questions should be asked or considered when assessing the material properties of a particular type of CPC:1,11
Is the material sufficiently durable to withstand the physical demands of the tasks at hand?
Will the material resist tears, punctures, cuts, and abrasions?
Will the material withstand repeated use after contamination and decontamination?
Is the material flexible or pliable enough to allow end users to perform needed tasks?
Will the material maintain its protective integrity and flexibility under hot and cold extremes?
Are garment seams in the clothing constructed so they provide the same physical integrity as the garment material?
In addition to evaluating these material characteristics, the CPC selected needs to match the type of protection desired. If liquid-splash protection is required, then the wearer’s entire body may require coverage using a suit, boots, gloves, and face protection (goggles and a mask, face shield, or full-face respirator or hood). Applying tape at suit/boot/glove/zipper/respirator interfaces provides additional splash protection but does not make the suit vapor protective.1 The nature of the hazards and the expected exposure will determine if the clothing should provide partial or full body protection. Splash protective suits guard against liquids and particulates, while vapor protective suits provide vapor, liquid-splash, and particulate protection. A totally encapsulated suit provides particulate and liquid-splash protection but may not universally offer gas-tight integrity. Demonstration of this capability requires the performance of a pressure or inflation test and a leak detection test of the respective suit (to assess the adequacy of the seams or closures).1,11
Most chemical protective suits require additional items to complete the ensemble. A vapor-protective, totally encapsulated suit will often have attached boots and gloves but still require the wearer to don a pair of inner gloves and boots. Liquid splash-protective suits are generally sold with or without an attached hood, shoe covers, or gloves. Missing items require separate purchases and must match or exceed the performance and protection level of the primary garment.
The gloves and boots selected should protect against a wide range of substances that might be encountered. Gloves and boots manufactured from either nitrile or butyl rubber ought to provide adequate protection in most circumstances. Other material options include neoprene, polyvinyl chloride, and natural rubber. Various glove thicknesses and lengths are available; with increased thickness comes greater degradation time but loss of manual dexterity. Double gloving of different materials offers enhanced hand protection and may reduce the need for thicker gloves. Frequent glove changes or glove decontamination are important when working with patients who were not fully decontaminated (e.g., those who self-refer to the emergency department or who arrive by transport with life- and limb-threatening injuries).11 Some adjustments in glove and boot fit can be made with the use of chemical or duct tape.
Information on the protective clothing’s chemical resistance, permeation rates, breakthrough times, and other testing data can be obtained from the manufacturer. If needed information is absent, the manufacturer should be asked to supply the missing data. Only suits certified by organizations such as NFPA or the European Committee for Standardization (CEN) should be considered for purchase. Organizations should obtain, inspect, and train using samples of CPC in which they are interested prior to purchase. Discussing various options for the ensembles with individuals experienced in their use should ensure that the appropriate PPE has been selected.
Respiratory Protection
A respirator is a protective device that covers the nose and mouth or the entire face and head to guard the wearer against hazardous atmospheres. Respirators are available as either air-purifying or atmosphere-supplying and may be tight fitting or loose fitting. A tight-fitting respirator includes half masks that cover the mouth and nose and full facepieces that cover the face from the hairline to below the chin. They create an air-tight seal around the area of contact. Loose fitting respirators utilize hoods or helmets that cover the head completely. An air-purifying model removes contaminants from the ambient air using filters or canisters while an atmosphere-supplying respirator provides clean, breathable air from an uncontaminated source such as a high-pressure cylinder. As a general rule, atmosphere-supplying respirators are used for more hazardous exposures. Specific examples of respirator types include the following:1,12,13,14
Self-contained breathing apparatus (SCBA) consists of a full facepiece connected by a hose to a portable air tank of breathing-quality compressed air worn by the user and provides the highest level of respiratory protection (Figure 15.1).
Supplied-air respirators (SAR) consist of a tight-fitting mask or a hood connected to a distant air source via an air hose. Because supplied-air respirators are less bulky than SCBAs (no tank is worn) and are typically connected to a larger air source, they can be used for longer periods of time (Figure 15.2).
Powered air-purifying respirators (PAPR) deliver filtered air under positive pressure to a tight-fitting mask or loose-fitting helmet/hood. Because PAPRs function under positive pressure, they provide a higher degree of respiratory protection as compared to a negative pressure mask. Hooded PAPRs are popular at hospitals because they minimize the administrative burdens associated with other types of respirators such as maintaining an appropriate air source and requiring annual fit testing (Figure 15.3). They can also be worn by people with facial hair and eyeglasses and are usually more comfortable for people who are not accustomed to regularly wearing respirators. For hazardous material (non-CBRN) operations, PAPR air filtering canisters used should include high efficiency (HE) particulate filters plus organic vapor (OV) and acid gas cartridges that together will protect against many of the more common airborne hazards that might be encountered (toxic dusts, biologicals, radioactive particulates, pesticides, and solvents).15
Air-purifying respirators (APR) consist of a tight-fitting mask worn over the mouth and nose with filters that work to reduce exposure of particulates or hazardous vapors present in ambient air before inhalation. APRs operate under negative pressure and are dependent on the inhalation effort of the wearer to draw air through a filter. All APRs are limited by the adequacy of their face seal and the efficiency of the filters (Figure 15.3).
Self-contained breathing apparatus (SCBA) shown in association with level A suits.
Atmosphere-supplying respirators: SCBA and SAR shown with Level B suits.
APR and PAPR with hood.
Levels of PPE
PPE ensembles are generally divided into various types, classes, or levels based on the certifying country, agency, and degree of protection afforded. The European system for chemical protective clothing designates CPC as Types 1–6 with corresponding standards describing the requirements on the products. Type 1 clothing provides the highest level of protection against solids, liquids, and gases (gas-tight); Type 2 provides similar protection but are not gas-tight; Type 3 provides liquid-tight protection; Type 4 are spray-tight protective clothing; Type 5 protects against particulates; and Type 6 is reserved for CPC that provides protection from liquids.16
NFPA, an international nonprofit organization with membership representing nearly 100 nations, issues standards for hazardous materials response teams, fire services, and first responders. NFPA certifications are only issued for complete ensembles (garments, boots, gloves, and respirators). Individual protective elements are not considered unless used as part of a complete and certified ensemble. An NFPA Class 1 ensemble provides the highest level of protection against toxic vapors, liquids, and particulates during hazardous materials incidents. The use of Class 1 suits is indicated in any environment where the concentration of a substance will exceed its immediately dangerous to life and health (IDLH) limits. The term IDLH refers to the maximum concentration level of a substance from which an individual could escape within 30 minutes of exposure without incapacitation or irreversible toxic effects. For example, the IDLH limit for hydrogen sulfide is 300 parts per million. The protection offered by an NFPA Class 1 ensemble includes specific chemical and biological agents in vapor, liquid-splash, and particulate environments during CBRN terrorism incidents. The ensemble consists of a suit with attached gloves that totally encapsulates the wearer and breathing apparatus.17
Class 2 NFPA ensembles include a suit or garment with attached or separate hood, attached or separate gloves, attached footwear or booties, outer protective boots, and SCBA. This ensemble is selected when the agent or threat has generally been identified and the actual release has subsided. It may also be used in terrorist incidents involving vapor or liquid chemical or particulate hazards where concentrations are at or above IDLH levels.17
NFPA Class 3 is intended for use long after the hazardous substance release has occurred or in the peripheral zone of the release scene. This includes terrorism incidents involving low levels of vapor or liquid chemical hazards where concentrations are below IDLH levels and includes non-encapsulating CPC with either an APR or PAPR. A Class 4 NFPA ensemble is the least protective and designated for use in situations involving potential exposure to biological aerosols or particles and low-level radiological particles.17 Typical Class 4 ensembles have not been tested for protection against chemical vapor or liquid permeability, gas-tightness, or liquid integrity. An APR or PAPR are permitted but not required.11
In the United States, CPC ensembles are also classified as levels A through D. These levels are EPA/OSHA recommendations for skin and respiratory protection and do not describe the clothing in detail. The various levels are described in the OSHA Hazardous Waste Operations and Emergency Response Standard (HAZWOPER), 29 CFR 1910.120 Appendix B.12 Each level consists of a combination of respiratory protection and clothing that guards against varying degrees of inhalation, eye, or skin exposure. Within each level of PPE, individual adjustments of ensemble components can be made (e.g., gloves and types of air purifying respirator protection selected) to align better aligned with the hazard assessment.12
Level A gear should be worn when the highest level of respiratory, skin, eye, and mucous membrane protection are required and corresponds to NFPA Class 1. The Level A suit is mandatory in an IDLH environment. A typical Level A ensemble is worn by hazardous material entry teams and includes a positive pressure (pressure-demand) SCBA or positive pressure SAR with an escape SCBA. The chemical protective suit is fully encapsulating and the wearer typically dons an inner and outer pair of chemical resistant gloves along with steel-toed, chemical resistant boots. Such a vapor-tight ensemble inhibits physiological cooling mechanisms, reduces mobility, and the limited air supply restricts the personnel who can utilize this capability. Responders working in a typical Level A ensemble, depending on ambient temperature and humidity, air capacity of the SCBA, and conditioning of the individual, are only able to remain in this gear for up to 20–30 minutes.
Level B should be selected when the highest level of respiratory protection is needed but a lesser level of skin and splash protection is required. This level is comparable to NFPA Class 2 and is the minimum protection recommended for initial site entry teams when the hazard has not been identified or defined by monitoring, sampling, and research. A typical Level B ensemble utilizes the same respiratory protection used with Level A along with non-encapsulating chemical resistant clothing, inner and outer chemical resistant gloves, and boots. This protective ensemble may offer more dexterity and mobility than Level A but remains dependent on an airline or limited air supply. Heat and physical stresses remain an issue and fit testing of the respirator is required.
A Level C ensemble provides the same level of splash protection as Level B, with a lower level of respiratory protection. It is comparable to NFPA Class 2 and is selected when the type and concentration of airborne substances are known and criteria for using an APR are met. Periodic air monitoring should be performed to ensure ongoing adequacy of the respirator and filter selected. The Level C ensemble includes a full-face or half-mask, APR or hooded PAPR with the same clothing, boots, and gloves as described for Level B. This protective ensemble provides for greater mobility and the associated heat and physical stresses are reduced. Operational time in the ensemble is increased with a high level of protection afforded against a limited number of chemical agents. Fit testing is not required if a positive-pressure respirator and hood combination are used. Level C does not provide adequate protection against exposure to toxic substances at high concentration levels (exceeding IDLH) or in low oxygen atmospheric environments.
In the United States, Level C protection is deemed appropriate for hospital personnel (first receivers) receiving and treating victims from mass-casualty incidents involving the release of unknown hazardous substances as long as certain criteria are met: 1) the hospital is not the release site or adjacent to it; 2) at least 10 minutes have elapsed between the time of victim exposure and arrival to the healthcare facility; and 3) the hazardous substance is not known (Tables 15.2–15.4). To use this level of protection, hospitals must first complete a hazard assessment that carefully considers an employee’s role in such an incident, the hazards that might be encountered, and the level of training required. In addition, the hospital must address the steps they will take to minimize the extent of the employee’s contact with hazardous substances. This OSHA PPE best practice is not universally applied to all hazardous materials releases. If the hazard assessment indicates the potential need for a higher level of protection (i.e., CBRN threat), then that PPE must be provided.3
Hospital Decontamination Zone
| Conditions necessary for hospitals to rely on the PPE selection presented in Table 15.4 |
|---|
| 1. Thorough and complete hazard vulnerability analysis (HVA) and emergency management plan (EMP), which consider community input, have been conducted/developed, and have been updated within the past year. |
| 2. The EMP includes plans to assist the numbers of victims that the community anticipates might seek treatment at this hospital, keeping in mind that the vast majority of victims may self-refer to the nearest hospital. |
| 3. Preparations specified in the EMP have been implemented (e.g., employee training, equipment selection, maintenance, and a respiratory protection program). |
| 4. The EMP includes methods for handling the numbers of ambulatory and non-ambulatory victims anticipated by the community. |
| 5. The hazardous substance was not released in close proximity to the hospital, and the lapse time between the victims’ exposure and victims’ arrival at the hospital exceeds approximately 10 minutes, thereby permitting substantial levels of gases and vapors from volatile substances time to dissipate. |
| 6. Victims’ contaminated clothing and possessions are promptly removed and contained (e.g., in an approved hazardous waste container that is isolated outdoors), and decontamination is initiated promptly upon arrival at the hospital. Hospital EMP includes shelter, tepid water, soap, privacy, and coverings to promote victim compliance with decontamination procedures. |
| 7. EMP procedures are in place to ensure that contaminated medical waste and wastewater do not become a secondary source of employee exposure. |
| And |
| 8. The decontamination system and pre-decontamination victim waiting areas are designed and used in a manner that promotes constant fresh air circulation through the system to limit hazardous substance accumulation. Air exchange from a clean source has been considered in the design of fully enclosed systems (i.e., through consultation with professional engineer or certified industrial hygienist) and air is not re-circulated. |
| Conditions necessary for hospitals to rely on the PPE selection presented in Table 15.4 |
|---|
| 1. EMP is developed and followed in a way that minimizes the emergency department (ED) personnel’s reasonably anticipated contact with contaminated victims (e.g., with drills that test communication between the hospital and emergency responders at the incident site to reduce the likelihood of unanticipated victims). |
| 2. Decontamination system (in the hospital decontamination zone) and hospital security can be activated promptly to minimize the chance that victims will enter the ED and contact unprotected staff prior to decontamination. |
| 3. EMP procedures specify that unannounced victims (once identified as possibly contaminated) disrobe in the appropriate decontamination area (not the ED) and follow hospital decontamination procedures before admission (or re-admission) to the ED. |
| 4. Victims in this area were previously decontaminated by a shower with soap and water, including a minimum of 5 minutes under running water. Shower instructions are clearly presented and enforced. Shower facility encourages victim compliance (e.g., shelter, tepid water, reasonable degree of privacy). |
| 5. EMP procedures clearly specify actions ED clerks or staff will take if they suspect a patient is contaminated. For example: 1) do not physically contact the patient; 2) immediately notify supervisor and safety officer of possible hospital contamination; and 3) allow qualified personnel to isolate and decontaminate the victim. |
| And |
| 6. The EMP requires that if the ED becomes contaminated, that space is no longer eligible to be considered a hospital post-decontamination zone. Instead, it should be considered contaminated and all employees working in this area should use PPE as described for the hospital decontamination zone (Table 15.4). |
