EOH502 2 CASE

Module 2 - Home

Chemical Hazards

Modular Learning Outcomes

Upon successful completion of this module, the student will be able to satisfy the following outcomes:

· Case

· Examine water pollution issues and their human health implications.

· SLP

· Apply principles of hazard recognition, evaluation and control to chemicals in the workplace.

· Discussion

· Analyze implications of persistent chemicals in the environment.

Module Overview

Water Pollution and Chemical Contamination

Dirty water is the world's biggest health risk, and continues to threaten both quality of life and public health in the United States. When water from rain and melting snow runs off roofs and roads into our rivers, it picks up toxic chemicals, dirt, trash, and disease-carrying organisms along the way. Many of our water resources also lack basic protections, making them vulnerable to pollution from factory farms, industrial plants, and activities like fracking. This can lead to drinking water contamination, habitat degradation and beach closures.

Principles of Recognition, Evaluation and Control of Occupational Hazards

Introduction to Worksite Analysis

A worksite analysis is an essential first step that helps an industrial hygienist determine what jobs and work stations are the sources of potential problems. During the worksite analysis, the industrial hygienist measures and identifies exposures, problem tasks, and risks. The most effective worksite analyses include all jobs, operations, and work activities. The industrial hygienist inspects, researches, or analyzes how the particular chemicals or physical hazards at that worksite affect worker health. If a situation hazardous to health is discovered, the industrial hygienist recommends the appropriate corrective actions.

Recognition of Occupational Hazards

To be effective in recognizing and evaluating on-the-job hazards and recommending controls, occupational health and safety professionals must be familiar with the hazards’ characteristics. Major job risks can include air contaminants, and chemical, biological, physical, and ergonomic hazards.

In this module, we will discuss air contaminants and chemical hazards.

Air Contaminants

These are commonly classified as either particulate or gas and vapor contaminants. The most common particulate contaminants include dusts, fumes, mists, aerosols, and fibers. Dusts are solid particles that are formed or generated form solid organic or inorganic materials by reducing their size through mechanical processes such as crushing, grinding, drilling, abrading, or blasting.

Fumes are formed when material from a volatilized solid condenses in cool air. In most cases, the solid particles resulting from the condensation react with air to form an oxide.

The term mist is applied to a finely divided liquid suspended in the atmosphere. Mists are generated by liquids condensing from a vapor back to a liquid or by breaking up a liquid into a dispersed state such as by splashing, foaming or atomizing. Aerosols are also a form of a mist characterized by highly respirable, minute liquid particles.

Fibers are solid particles whose length is several times greater than their diameter.

Gases are formless fluids that expand to occupy the space or enclosure in which they are confined. Examples are welding gases such as acetylene, nitrogen, and helium. And argon and carbon monoxide generated from the operation of internal combustion engines or by its use as a reducing gas in a heat-treating operation. Another example is hydrogen sulfide, which is formed wherever there is decomposition of material containing sulfur under reducing conditions.

Liquids change into vapor and mix with the surrounding atmosphere through evaporation. Vapors are the volatile form of substances that are normally in the solid or liquid state at room temperature and pressure. They are formed by evaporation from a liquid or solid and can be found where parts' cleaning and painting takes place and where solvents are used.

Chemical Hazards

Harmful chemical compounds in the form of solids, liquids, gases, mists, dusts, fumes, and vapors exert toxic effects by inhalation (breathing), absorption (through direct contact with the skin), or injection (eating or drinking). Airborne chemical hazards exist as concentrations of mists, vapors, gases, fumes, or solids. Some are toxic through inhalation and some of them irritate the skin on contact; some can be toxic by absorption through the skin or though ingestion and some are corrosive to living tissue.

The degree of worker risk from exposure to any given substance depends on the nature and potency of the toxic effects as well as the magnitude and duration of exposure.

Sampling and Analysis of Occupational Hazards

Chemical sampling and analysis is used by occupational health and safety professionals to assess workplace contaminants and associated worker exposures. The validity of an assessment is based, in part, on the procedures used for sample collection and analysis, and data interpretation.

Controlling Occupational Hazards

Industrial hygienists recognize that engineering, work practice, and administrative controls are the primary means of reducing employee exposure to occupational hazards. Engineering controls minimize employee exposure by either reducing or removing the hazard at the source or isolating the worker from the hazards.

Engineering controls include eliminating toxic chemicals and replacing harmful toxic materials with less hazardous ones, enclosing work processes or confining work operations, and installing general and local ventilation systems.

Work practice controls alter the manner in which a task is performed. Some fundamental and easily implemented work practice controls include (1) following proper procedures that minimize exposures while operating production and control equipment; (2) inspecting and maintaining process and control equipment on a regular basis; (3) implementing good house-keeping procedures; (4) providing good supervision and (5) mandating that eating, drinking, smoking, chewing tobacco or gum, and applying cosmetics in regulated areas be prohibited.

Administrative controls include controlling employees' exposure by scheduling production and workers' tasks, or both, in ways that minimize exposure levels. For example, the employer might schedule operations with the highest exposure potential during periods when the fewest employees are present.

Personal Protective Equipment: When effective work practices and/or engineering controls are not feasible to achieve the permissible exposure limit, or while such controls are being instituted, and in emergencies, appropriate respiratory equipment must be used. In addition, personal protective equipment such as gloves, safety goggles, helmets, safety shoes, and protective clothing may also be required. To be effective, personal protective equipment must be individually selected, properly fitted and periodically

Module 2 - Outcomes

Chemical Hazards

· Module

· Examine the health implications of chemical hazards in the environment and apply principles of hazard recognition, evaluation, and control of chemical hazards in the workplace.

· Case

· Examine water pollution issues and their human health implications.

· SLP

· Apply principles of hazard recognition, evaluation and control to chemicals in the workplace.

· Discussion

· Analyze implications of persistent chemicals in the environment