HAZWOPER 4: Hazard Recognition

Chemical Physical Hazards: Flammable Solids

Flammable solids, unlike a blasting agent or explosive, cause fire through friction, absorption of moisture, spontaneous chemical change, or retained heat from manufacturing or processing. If ignited, a flammable solid can burn vigorously posing a serious hazard. Examples include some metals like trinitrotoluene, naphthalene, and methyl parathion.

Human Immunodeficiency Virus (HIV)

HIV is the virus that causes AIDS by attacking the body's immune system, reducing its ability to fight disease. Early AIDS symptoms can include fever, loss of appetite, weight loss, chronic fatigue, and skin rashes. Later, the victim may develop unusual types of cancer or infections, including pneumonia that the body can no longer suppress.

Hazard Recognition

Hazardous waste sites pose various health and safety concerns, which can seriously inflict harm or death. It is nearly impossible to specifically assess all hazards posed by the waste site due to the large number and variety of substances. Any specific location can contain hundreds or even thousands of chemicals. In addition, workers are subject to dangers posed by the disorderly physical environment of hazardous waste sites and the stress of working in protective clothing. The combination of these conditions results in a working environment full of numerous hazards.

Electrical Hazards

Hazardous waste sites require an electrical supply for lighting, cooling, equipment, and tools. Whenever electricity is used, proper precautions and procedures are necessary to avoid electrocution and shock.

Environmental Hazards

Heat Stress The workers wearing protective clothing can experience heat stress. The same protective materials that guard the body from chemical exposure reduce the ability of the body to release heat and moisture. So, personal protective clothing can actually create a hazardous condition. Depending on the ambient conditions and the work being performed, heat stress can occur very rapidly, within as little as 15 minutes.

Chemical Physical Hazards: Combustible Liquids and Flammable Gases, Aerosols, and Liquids

Ignited spontaneously, these chemicals are hazardous when exposed to an ignition source or an oxidizer, such as air. Some common instances are coal tar distillate, acetylene, methane, toluene, and naphtha.

Prevent Electrical Accidents

In order to avoid electrical accidents, preplanning is needed as well as worker hazard awareness. Be sure to: Locate buried cable and note location of overhead lines before using heavy equipment. Isolate and cut off the power to downed or abandoned power lines. Instruct workers in the proper precautions for using electrical tools. Assure proper classification of tools and equipment for hazards present (e.g., use explosion proof lighting in an area with flammables).

Hazard and Safety Analysis

Job safety analysis, or JSA, assesses the potential hazards posed by doing a specific task. These are the steps taken when performing a JSA: Identify the site tasks that have the potential for injury or illness. List the steps involved to perform the task. Use the steps to identify potential hazards associated with each step. Determine the best method of protection.

Solutions:

Make this information accessible to employees at all times in a language or formats that are clearly understood by all affected personnel. Train employees on how to read and use the SDS. Follow manufacturer's SDS instructions for handling hazardous chemicals. Train employees about the risks of each hazardous chemical being used. Provide spill clean-up kits in areas where chemicals are stored. Have a written spill control plan. Train employees to cleanup spills, protect themselves and properly dispose of used materials. Provide proper personal protective equipment and enforce its use. Store chemicals safely and securely.

Chemical Health Hazards

Many chemicals can affect our health. Health hazards cause short or long term effects on health. Corrosive class substances, polychlorinated biphenyls, carcinogens, irritants, mutagens, teratogens, asphyxiants, and target organ poisons are health hazards that can be found at a hazardous waste site. Hazard Failure to recognize the hazards associated with chemicals can cause chemical burns, respiratory problems, fires and explosions.

Primary and Secondary Hazards

Many materials have more than one of these hazards associated with it. A secondary hazard or subsidiary hazard can be as important in dealing with a material as the primary hazard. For example, gasoline is a fire hazard because it is flammable. It could also be classified as a chemical health hazard because it is organic solvent and can cause illness if the vapors are inhaled or a significant quantity makes skin contact. A worker must be aware of the multiple hazards of the materials they deal with to be protected from them. Site personnel, in order to maintain health and safety, should constantly watch for any potential safety hazards and immediately report to their supervisors any new hazards so that necessary precautions are taken.

Fire and Explosions

Many potential causes govern fires and explosions at hazardous waste sites. Fires and explosions are dependent on the materials involved and the conditions to which the materials are subjected.

DOT Labels

Nine hazard classes are defined by the Department of Transportation (DOT), which have corresponding labels associated with them. Some of the classes have subdivisions that are noted by a decimal and a subdivision number following the hazard class number. These labels should be found on all transported packages that contain hazardous materials. At a waste site these could be drums, tanks, laboratory boxes, or compressed gas cylinders. The labels indicate a general hazard but not specific chemical names. Each label tells the name and number of the hazard class and uses unique color combinations to distinguish the classes from one another.

Bloodborne Pathogens

OSHA has devised a standard to address the risks of contacting bloodborne pathogens in the workplace. The two viruses of greatest concern are Hepatitis B and HIV (human immunodeficiency virus). OSHA Standard 29 CFR 1910.1030 requires that the employer establish a written exposure control program when employees can be exposed as part of their duties.

Other Environmental Hazards

Other environmental hazards that can be present at hazardous waste sites are as follows: Plants, such as poison ivy, which cause severe allergic reactions in some people. Poisonous insects, such as hornets, wasps, and bees, which cause severe allergic reactions in some people when stung. Snakes and other animals that bite. Insects, such as ticks and spiders, which can cause severe illness. Workers experiencing severe allergic reactions should inform the medical surveillance program physician and those responsible for administering first aid on-site.

Other Site Hazards

Other safety hazards are a function of the work itself. Examples include: Heavy equipment Protective equipment, which impairs a worker's agility, hearing, and vision Power tools, which can create a hazard when used improperly or without safety guards or precautions

Chemical Physical Hazards: Oxidizers

Oxidizers instigate or promote combustion in other organic materials through the release of oxygen or other gases that support burning. Oxidizers themselves do not burn. Another fuel must be present. Some examples are nitrates, chlorine, fluorine, hydrogen peroxide, permanganates, and hypochlorites.

Biological Hazards

Pathogens are biological organisms that are capable of infecting or transmitting diseases to humans. For instance, bacteria, viruses, and fungi can be present in waste from hospitals or research facilities. It is important to recognize and protect against biological hazards.

Chemical Physical Hazards

Physical hazards can cause physical injury, such as by fire or explosion. Physical hazards of chemicals can injure workers and create additional hazards. For example, an explosion can increase chemical exposure due to the mixing of chemicals. Such releases can threaten both personnel on-site and the general public living or working nearby. The physical hazards related to chemicals are chemical specific and may comprise any of the situations that follow.

Chemical Physical Hazards: Unstable Reactives

Reactive chemicals will vigorously polymerize, decompose, condense, or become self-reactive under conditions of shock, pressure, or temperature. This can cause a sudden release of materials under pressure or chemical reactions that produce explosions, fire, or heat. Examples include acetylene and vinyl chloride.

For construction, the 10 OSHA standards most frequently included in the agency's citations in FY 2004 were:

Scaffolding Fall protection (scope, application, definitions) Excavations (general requirements) Ladders Head protection Excavations (requirements for protective systems) Hazard communication Fall protection (training requirements) Construction (general safety and health provisions) Electrical (wiring methods, design, and protection)

NFPA 704 System

The NFPA marking system engages the identification of three areas of concern to first responders as they enter a building or area in addressing a potential fire situation. Each area of concern is identified by a color and takes up one-fourth of a diamond shaped sign; the fourth quarter, which is white, is reserved for noting special hazard situations. Each colored area contains a number ranging from 0 to 4 representing the degree of danger for that area. A rating of 4 indicates the highest level of concern.

Safety Checklists

The following checklists may help you take steps to avoid hazards that cause injuries, illnesses, and fatalities. As always, be cautious and seek help if you are concerned about a potential hazard. A list of hazardous substances used in the workplace is maintained and readily available at the worksite. There is a written hazard communication program addressing Safety Data Sheets (SDS), labeling, and employee training. Each container of a hazardous substance (vats, bottles, storage tanks) is labeled with product identity and a hazard warning(s) (communicating the specific health hazards and physical hazards) as required by OSHA, DOT, and the United Nations. There is an effective employee training program for hazardous substances.

Hepatitis B Virus (HBV)

The hepatitis B virus infects the liver. In some individuals, HBV develops into serious or fatal problems, such as cirrhosis, liver cancer, or chronic liver disease. Some people have no problems or symptoms yet they become carriers of the virus. HBV is more common and is a much hardier virus than HIV. It can exist on a surface outside the body for up to seven days. For this reason, it poses a greater hazard to an exposed individual.

Oxygen Deficiency

The oxygen content of normal air at sea level is approximately 21 percent. Physiological effects become readily apparent when the oxygen concentration approaches 16 percent. These effects include impaired attention, judgment and coordination, as well as increased breathing and heart rate. When the oxygen concentration drops lower than 16 percent, the effect is much more severe. A concentration as low as 16 percent can result in nausea and vomiting, brain damage, heart damage, unconsciousness, and death. To account for individual physiological responses as well as errors in measurement, OSHA requires the use of supplied-air respirators at concentrations of 19.5 percent oxygen or lower.

Bloodborne Diseases

The two viruses of greatest concern are Hepatitis B and HIV. To minimize exposure to bloodborne diseases: Do not clean up blood or body fluids unless you have been trained in how to do so. Know what to do before an emergency occurs. Be sure to wash your hands and remove any PPE before eating, drinking, smoking, or handling contact lenses.

Exposure Control Program (ECP)

The written ECP includes: Engineering controls, like sharps disposal containers and self-sheathing needles. Hand-washing facilities to ensure good sanitation. For example, providing an adequate supply of running potable (drinkable) water, soap, and single-use towels or hot air drying machines. Work practice controls, including PPR, that minimize or eliminate employee exposure. Universal precautions which mean that all human blood and certain human body fluids are to be treated as infectious.

WHITE - Special Information

This block is designated for special information about a chemical present. For example, it may indicate that a material is radioactive by displaying the standard radioactive symbol or unusually water reactive by displaying a large W with a slash through it. For a more complete discussion of these various hazards, consult NFPA Standard 704 M (NFPA, 1986).

Lesson Focus

This lesson focuses on the following topics: Hazard Recognition Definitions Hazard and Safety Analysis Hazard Recognition Chemical Health Hazards Site and Equipment Hazards Environmental Hazards Biological Hazards

Lesson Description

This lesson, Hazard Recognition, addresses both chemical and biological hazards that can be encountered in the hazardous waste site environment. How to do a job safety analysis (JSA) is explained in detail because this is how employers identify hazards that need to be controlled. This lesson explains the hazard identification systems like NFPA signage and DOT package labels that must be used to alert workers of present or potential danger. Finally, a detailed discussion of common environmental and biological hazards is given. This section effectively alerts employers and workers to specific dangers and lists ways to protect against them.

Prevention

To protect from cold exposure: Wear appropriate clothing. Make a warm shelter readily available. Carefully schedule work and rest periods. Monitor workers' physical conditions.

Introduction

When employees might be exposed to hazardous substances as part of their duties, prevention must include protection from physical harm as well. Other concerns include allergic reactions, overheating, oxygen deficiency, or even shock or electrocution. Material Safety Data Sheets (MSDSs), proper labeling, and employee awareness go a long way toward addressing such issues as improper substance handling, mere careless, or accidental chemical exposure, mixture, or friction that could result in fire or explosion. Even the introduction of water or temperature change is enough to cause reactions in some instances, so safety and training go hand in hand.

RED - Flammability Hazard

4 Materials that (1) rapidly or completely vaporize at atmospheric pressure and normal ambient temperatures and burn readily or (2) are readily dispersed in air and burn readily. 3 Liquids and solids that can be ignited under almost all ambient temperatures. 2 Materials that must be moderately heated or exposed to relatively high ambient temperatures before ignition can occur. 1 Materials that must be preheated before ignition can occur. 0 Materials that will not burn.

BLUE - Health Hazard

4 Materials that on very short exposure could cause death or major residual injury even though prompt medical treatment was given. 3 Materials that on short exposure could cause serious temporary or residual injury even though prompt medical treatment was given. 2 Materials that on intense or continued exposure can cause temporary incapacitation or residual injury without prompt medical treatment. 1 Materials that on exposure would cause irritation but only minor residual injury even if no treatment were given. 0 Materials that on exposure under fire conditions would offer no hazard beyond that of ordinary combustible material.

YELLOW - Reactivity Hazard

4 Materials those in themselves are readily capable of detonation or of explosive decomposition or reaction at normal temperatures and pressures. 3 Materials that (1) in themselves are capable of detonation or explosive reaction but require a strong initiating source or (2) must be heated under confinement before initiation or (3) react explosively with water. 2 Materials that (1) in themselves are normally unstable and readily undergo violent chemical change but do not detonate or (2) may react violently with water or (3) may form potentially explosive mixtures with water. 1 Materials that in themselves are normally stable but which can (1) become unstable at elevated temperatures or react with water with some release of energy but not violently. 0 Materials that in themselves are normally stable, even when exposed to fire, and that do not react with water.

Chemical Physical Hazards: Pyrophorics

A pyrophoric is a chemical that ignites impulsively in air at or below 130 degrees Fahrenheit. Some examples are phosphorous, trimethyl aluminum, powdered cesium, and dimethyl zinc.

To eliminate explosions and fires, the site health and safety plan must contain these procedures:

Allow only qualified personnel to field monitor explosive atmospheres and flammable vapors. Use proper precautions and procedures when staging and storing incompatible/reactive materials. Keep all potential ignition sources away from an explosive or flammable environment. Obtain a "Hot Work Permit" prior to conducting any operation that could introduce an ignition source such as grinding, cutting or welding on metal producing sparks. Use non-sparking, explosion proof equipment, grounded equipment. Follow established safe work practices when performing any task that might result in the agitation or release of chemicals.

Ionizing Radiation

Alpha and Beta particles as well as Gamma rays are radiological hazards. Only monitoring detect ionizing radiation. Radiation associated hazards are discussed later in this course.

Chemical Physical Hazards: Explosives

An explosive causes a sudden, almost instantaneous, release of pressure, gas, and heat when subjected to sudden shock, pressure, or high temperature. DOT distinguishes six subcategories of explosives, depending upon their particular behavior (i.e., Division 1.3 - "Explosives that have a fire hazard and either a minor blast hazard or minor projection hazard or both, but not a mass explosion hazard."). Some examples of explosives are initiating explosives or blasting agents, grenades, rocket engine propellant, fuse igniters, and explosive cable cutters

Learning Objectives

At the completion of this lesson, you will be able to: Distinguish between National Fire Protection Association (NFPA) and Department of Transportation (DOT) insignia. Summarize the meaning of the NFPA 704 System. Name common chemical physical hazards. Discuss the two viruses of greatest concern in the workplace. Explain the objectives of an Exposure Control Program (ECP).

Hazard Recognition Definitions

Before discussing how to identify and handle hazards at a waste site, it is important to understand some key definitions. A hazard is any substance, situation, or condition that is capable of harming human health, property, or the environment. It represents a potential for harm. A risk is a measure of the probability and severity of a hazard to harm human health, property, or the environment. Safety is a judgment about the acceptability of risk. A Site Health and Safety Officer is responsible for assessing the potential risk of a hazard, if the level of risk is acceptable, and if something needs to be done to lower the risk.

Chemical Physical Hazards: Water Reactives

Chemicals in this group react with water to release a gas that is flammable and can be a health hazard. Water reactive chemicals can cause fire, explosion, or excessive pressure leading to container failure. Examples include sodium metal, sulfuric acid, vinyl chloride, arsine, and trifluorochloroethylene. Explosions and fires may arise spontaneously.

DOT Hazard Classes Following are the hazard classes, subdivisions, and corresponding labels:

Class/Division Name Label 1.1 Explosives Explosive 1.1 1.2 Explosives Explosive 1.2 1.3 Explosives Explosive 1.3 1.4 Explosives Explosive 1.4 1.5 Explosives Explosive 1.5 1.6 Explosives Explosive 1.6 2.1 Flammable Gas Flammable Gas 2.2 Nonflammable Gas Nonflammable Gas 2.3 Poisonous Gas Poison Gas 3 Flammable Liquids Flammable Liquid Combustible Liquids None 4.1 Flammable Solid Flammable Solid 4.2 Spontaneously Combustible Spontaneously Combustible 4.3 Dangerous When Wet Dangerous When Wet Materials 5.1 Oxidizer Oxidizer 5.2 Organic Peroxides Organic Peroxide 6.1 Poisonous Materials Poison 6.2 Infectious Substances Infectious Substance 7 Radioactive Materials Radioactive White - I 7 Radioactive White - II 7 Radioactive White - III 7 (empty packages) Empty 8 Corrosive Materials Corrosive 9 Miscellaneous Hazardous Class 9 Materials

hemical Physical Hazards: Organic peroxides

Considered a structural derivative of hydrogen peroxide, organic compounds fall in this category. They chemically contain both the oxidizer and the fuel to support combustion and under conditions such as contamination, elevated temperatures, and friction, they can act as contact explosives. Instances include benzoyl peroxide, t-butyl peracetate, isopropyl percarbonate, and tamyl peroxypivalate.

Hazard Identification Systems

Due to the large variety of substances on a waste site, an accurate assessment of all the hazards posed is nearly impossible. A JSA is a helpful way to identify hazards associated with a particular task and creates a record that can be included in a health and safety plan. Commonly used identification systems that help in recognizing potential chemical hazards are NFPA (National Fire Protection Association) signage and DOT (Department of Transportation) package labels.

Site and Equipment Hazards

Everyday objects and conditions at a work site can cause site equipment hazards. Some of these hazards include holes or ditches, sharp objects, or broken glass. Although some hazards may seem small, they can have serious consequences. Other site and equipment hazards include noise and electrical hazards. Workers can be startled or distracted by a loud noise, or an exposed live wire can lead to electrocution or shock

Noise

Excessive noise is often created during work with heavy equipment. If workers are unable to communicate and are distracted, the chances of injuries increase. When workers need to raise their voices, it is a good indicator that the noise levels have exceeded OSHA's PEL (90dBa 8hr-TWA). Further monitoring should be done and a plan to reduce exposure developed. The adverse effects of noise are: Workers being troubled, annoyed, or distracted Physical damage to the ear, pain, and temporary or permanent hearing loss Inability to communicate/intrusion

Cold Exposure

Exposure to low temperatures and wind-chill factors can cause injury (i.e., frostbite and hypothermia) and impair one's ability to work. Frostbite is a local injury, which can range from a sudden whitening of the skin to cold, pale, and solid skin. Hypothermia, which is an abnormally low body temperature, can result from exposure to freezing, rapidly dropping temperatures, and prolonged exposure to wet conditions or cool temperatures.