Chapter 10: Occupational Safety and Health

OSHA- Hazard Communication Standard requirements

-Identification of operations in the workplace where hazardous chemicals are present -Methods and observations used to detect the presence of hazardous chemicals in the work area -Physical and health hazards of those chemicals -Hazards associated with chemicals in unlabeled pipes -Hazards of non-routine tasks -Measures that employees can take to protect themselves from these hazards -Explanation of chemical labeling system -Explanation of Safety Data Sheets (SDS) -Details on the availability and locations of the Hazardous Material Inventory, SDS, and other printed Hazard Communication Program materials

2. No persons should be permitted to work in a trench or pit in sandy clay soil that has unsupported sides or banks higher than: (A) 2 feet (B) 3 feet (C) 4 feet (D) 5 feet

D

acute hazards

a sudden reaction to a severe condition; for example, an employee slipping on wet pavement and falling

Extremes of pressure

may be experienced by workers under pressures greater than normal atmospheric pressure, such as environments encountered by divers working underwater or those working in a compressed-gas environment. Teeth, sinuses, and ears are often affected by pressure differentials.

Ergonomic hazards

Repetitive motion or cumulative trauma are the most frequently encountered occupational illness. Many health and safety problems in the workplace are caused by physical stresses imposed on workers by improperly designed equipment or work environments. Such stresses include repetitive motions, forceful motions, awkward or static pstures, and vibration. All can lead to pain and physical damage. Redesigning equipment and work environments is called human factors engineering, or ergonomics. Ergonomics is increasingly being recognized as an important way to prevent both acute and chronic injuries.

Noise dosimeters

are attached to a worker to measure noise exposure throughout the workday. The worker may move to several locations in the course of the day, each generating different sound levels. The dosimeter records the various sound levels during the work shift.

Occupational Exposure Limits (OELs)

are based upon best available information from industrial experience, experimental human studies, and experimental animal studies. Information gathered from industrial experience usually is a result of the substance having such harmful effects that numerous workers experience adverse health effects. The majority of our information comes from animal studies.

4. A negative pressure fit test for a protective mask: (A) Is done by placing both palms against the intake filters (B) Is done by placing both hands over the exhalation points (C) Should be conducted at a minimum of once a week (D) Should be repeated until an air leak is detected

A

5. Quantitative risk assessments USUALLY measure human exposure through all of the following EXCEPT: (A) Computer models (B) Blood or urine analysis (C) Personal surveys (D) Toxicological analysis

A

OELs

-Time weighted average (TWA): the average concentration to which a worker may be repeatedly exposed for a normal 8-hour workday or 40-hour work week without suffering adverse effects -The short-term exposure limit (STEL): is the maximum concentration to which workers can be exposed for periods of up to 15 minutes without suffering irritation, chronic or irreversible tissue change, or narcosis of significant degree to increase the likelihood of accidental injury, impair self-rescue, or materially reduce work efficiency. A STEL is a 15-minute TWA exposure that should not be exceeded at any time throughout the workday. -The ceiling (C): The concentration that should not be exceeded during any part of the workers' exposure.

Skin absorption

Although the skin acts as an effective barrier against some chemicals, cuts and abrasions offer the possible path for rapid absorption of various compounds. Many compounds may also be absorbed through intact skin. An organic compound, such as cyanide or phenol can produce systemic poisoning by direct contact with the skin.

1. What is the danger and/or hazard posed by an etiological agent? (A) Corrosive reaction (B) Asphyxiation (C) Human disease (D) Allergic reaction

C

3. An employer moves employees who have reached the upper permissible level of exposure to a hazardous environment, to prevent further exposure. What type of hazard control is this? (A) Professional control (B) Personal control (C) Administrative control (D) Engineering control

C

Chemical hazards

Chemical agents comprise the largest category of occupational hazards. Degree of risk is determined by the magnitude of the substance and the duration of exposure. To fully evaluate magnitude (dose), it is necessary to know the raw materials used and the products and byproducts produced when the materials are combined. Chemical hazards may take the form of inhalation of vapors, gases, dusts, fumes, and mists; by skin contact with the substance; or by ingestion of toxic materials. Solvents are used in industrial, occupational, and non-occupational environments and are occupationally important because of their widespread use and their many different properties. Organic solvent vapors enter the body mainly by inhalation and also by skin absorption. Substances are converted to solutions by solvents, and their combinations are nearly infinite. When determining the effects of exposure to solvents, the occupational health professional is challenged with determining which effects are harmful and at what level. The solvent hazard is determined not only by its toxicity, but also by the nature and conditions of its use. Information about the chemicals being used may be obtained from the SDS. The Hazard Communication Standard requires that all hazardous materials be supplied with an SDS. The SDS summarizes the health, safety, and toxicological data on the chemical or the combination of chemicals used. Chemicals that are listed as dangerous materials are those that may, under specific circumstances, cause injury to persons or damage to property because of reactivity, instability, spontaneous decomposition, flammability, or volatility.

OSHA Standards

Design standards - refer to detailed design criteria. Ventilation design is an example of a design standard. Performance standards - emphasize results. Threshold limit values (TLVs) are an example of performance standards; that is, they state the objective that must be obtained, but allow the employer the freedom to determine the method to obtain it. Vertical standards - are those standards that apply only to particular industry with specifications that relate to individual operations. Horizontal standards - apply to everyone. Standards that relate to sanitation are examples of horizontal standards.

Biological hazards

Exposure to biological hazards in the workplace, such as infectious microorganisms, biological allergens, and toxins, results in a significant amount of occupationally associated disease. workers engaging in agricultural, medical and laboratory activities have been identified as being most at risk to occupational biohazards, but many varied workplaces have the potential for such exposure. Microorganisms include bacteria, fungi, algae, protozoa, and viruses. Although pathogenic microorganisms represent only a small portion of the total microbial population, attention is often focused on them because of their negative impact on humans, plants, and animals. In addition to their infectious disease-causing capability, microorganisms such as fungi produce spores capable of causing allergic reactions among workers. Toxins such as endotoxin, a component in the cell walls of gram-negative bacteria, and mycotoxin, a natural product produced by fungi, have also been identified as occupation biohazards. Other biological agents such as pollen, mites, urine proteins, and animal dander, to list a few, also fit within the broad scope of biological hazards.

Skin disease

Industrial dermatoses are the second most frequently encountered occupational illness. NIOSH estimated in 1986 that skin injuries may account for 23%-35% of all injuries. The highest percentage is due to lacerations and punctures followed by burns (both chemical and other).

Inhalation

Inhalation involves gases, vapors, and particulate matter including dusts, fumes, smokes, aerosols, and mists. Airborne contaminants are inhaled directly into the lungs and are important hazards because of how rapidly they can be absorbed. In addition, the lungs have a much greater surface area than skin.

Physical Hazards

Occupational physical stresses include noise, temperature extremes, pressure extremes, ionizing radiation, and non-ionizing radiation. Noise, defined as unwanted sound, may result in psychological effects such as loss of hearing. Permissible levels of noise to which employees may be exposed are defined in 29 CFR 1910.95 (OSHA Act). For example, exposure to 90 dB (A) is permissible for a duration of 8 hours. The Hearing Conservation Amendment to 29 CFR 1910.95 requires the administration of a hearing conservation program whenever the sound levels exceed 85 dB (A) on an 8-hour, time-weighted average.

Degree of hazard

The degree of hazard related to exposure in harmful environments depends on the nature of the material involved, the intensity of the exposure, and the duration of the exposure. Key elements to consider include: how much of the material is required to produce injury when it comes in contact with the body, the probability that the material being absorbed by the body will result in an injury, the rate that airborne contaminant is generated, the total time of contact, and the control measures used.

Respiratory hazards

The respirtory system includes the nose, mouth, upper throat, larynx, trachea, bronchi, lungs, diaphragm, and the muscles of the chest. Oxygen passes through the lungs into the blood, and carbon dioxide is given off. Respiratory hazards are categorized in two main groups: oxygen deficiency and toxic air. In oxygen deficiency, the oxygen concentration is lower than the level considered safe for human exposure. The body requires a constant supply of oxygen. Certain cells, such as cells in the brain and nervous system, can be injured or die after four to six minutes without oxygen. If destroyed, these cells are not regenerated or replaced. Impaired functioning of the brain can result from such damage. The first physiological signs of an oxygen deficiency (anoxia) are an increased heart rate and shortness of breath. If oxygen concentrations are less than 16% by volume, dizziness, rapid heartbeat, and headache may occur. Workers should not enter areas of oxygen deficiency without wearing self-contained breathing equipment. An appropriately trained individual must be called upon to test any location for oxygen deficiency if there is any possibility that an oxygen-deficient atmosphere exists.

Ingestion

Workers can unknowingly eat or drink harmful agents. Toxic compounds are capable of being absorbed from the gastrointestinal tract into the blood. For this reason it is important to separate areas where workers may eat or smoke from areas in which they work.

Atmospheric air portable monitors

are used to determine if the atmosphere contains combustible gas, oxygen deficiency, or oxygen in excess. These monitors may also detect toxic gases, such as carbon monoxide and hydrogen sulfide, at hazardous levels. Oxygen does not have a specific threshold limit value, and excess oxygen can result in fire hazard and should be monitored. Normal atmospheric air contains about 21% oxygen by volume. The minimum amount of oxygen necessary to support life is 16%. Oxygen monitors will sound an alarm when the oxygen drops below 19.5%. Monitors generally contain three functions: combustible gas function, oxygen deficiency function, and a toxic gas cell function. The monitor digitally displays levels within seconds and alarms the user when dangerous levels are crossed.

Sound level meters

are used to measure sound pressure variations in air. This instrument contains a microphone, an amplifier with a calibrated alternator, a set of frequency response networks (weighting networks), and an indicating meter. Various frequencies can be controlled by electrical weighting networks. The A-weighting network is the network that is the closest to the perception f sound heard by the human ear and is the network that is used to determine compliance with OSHA standards.

Extremes in temperature

can affect the amount of work the worker is able to do. In industry, high temperatures are more problematic than low temperatures. Exposure to high temperatures may result in heat stress, heatstroke, heat cramps, or heat exhaustion. Hypothermia and frostbite may result from exposure to cold stress.

Toxic air

contains harmful or toxic contaminants that can irritate the upper respiratory tract and lung tissue or the terminal passages of the lungs ans the air sacs. Inhaled contaminants that adversely affect the respiratory system fall into three categories: (1) Particulates that, when in the lungs, can produce tissue damage or tissue reaction, and eventual disease. An example of this is silica dust, which can cause fibrotic growth in the lungs; (2) Toxic gases that produce adverse reaction in the tissue of the lungs, such as hydrogen fluoride, which can prevent the blood from carrying oxygen to the tissues; (3) Toxic gases that have an adverse effect on the oxygen-carrying capacity of the blood cells but do not affect the lung tissue. An example of this is carbon monoxide, a toxic gas passed into the bloodstream without essentially harming the lung.

Octave-band analysis

determine where the noise energy is in the frequency spectrum. This is particularly useful when engineering control of noise problems is planned.

Control and prevention measures

engineering controls, ventilation, administrative controls, and personal protective equipment

chronic hazards

is a deterioration due to a prolonged exposure of adverse condition. Long-term exposure to industrial noise is an example of a chronic effect. Chemical exposures may have both an acute and a chronic effect and thus are both safety and health hazards.

Non-ionizing radiation

is a form of electromagnetic radiation that includes microwaves, infrared radiation, visible radiation (lighting), ultraviolet radiation, and lasers. Microwaves may be high enough in intensity to cause significant heating of tissue. flammable gases and vapors can ignite when they are inside metallic objects located in a microwave beam. Infrared radiation can heat the skin and tissue just beneath the skin (thermal burns). Visible radiation plays an important role in occupational health because good lighting increases productivity and decreases the incidence of injury. The most common source of ultraviolet radiation is from direct sunlight, the result being sunburn. Electrical arcs are also a source of ultraviolet radiation and should be shielded. Laser energy is most hazardous to the eye, and suitable shielding should be provided to shield the laser beam. Health and safety issues associated with low-level electromagnetic radiation can include the hazards related to shocks and currents. Other health and safety issues are related to extremely low-frequency (ELF) radiations. The most common, strongest ELF field exposures are those produced by electric power generation, transmission, and distribution.

Ionizing radiation

is determined by the kinds of radioactivity that are emitted and whether they pose an external versus an internal hazard. Materials that emit X-rays, gamma-rays, or neutrons are external hazards. These materials can emit radiation the will produce ionization, which causes damage as it passes through the body. Alpha-emitting radioactive material is considered an internal hazard. As long as it remains outside the body, it will not cause tissue damage in most cases. However, if somehow it is ingested, inhaled, or enters through an open wound, it can cause considerable damage. Beta-emitting radioactive material is usually considered to be an internal hazard, but it can also be classified as an external hazard because of its ability to produce burns when it comes in contact with the skin. Gamma radiation is mainly an external hazard.

Threshold Limit Values (TLVs)

refer to exposure guidelines, established by the American Conference of Governmental Industrial Hygienists (ACGIH), for airborne concentrations of chemical compounds to which workers can be exposed daily without adverse effect. This is based on an assumption that for each substance there is some tolerable level of exposure below which no significant adverse effect occurs.

Ergonomics

the application of human biological science in conjunction with the engineering sciences to achieve the optimum mutual adjustment of man and his work, the benefits being measured in terms of human efficiency and well-being.