Read the background and scenario descriptions in Sections I and II of the instructions. Prepare a paper addressing each of the subsections of Section III. Make sure you read each section completely and carefully before preparing your paper.
I. Background
Acme International has a small manufacturing shop that includes two welding stations and a separate paint room. Two welders produce small components for automobiles using stainless steel and MIG welding. After grinding has been performed in the welding bays, the parts are painted in the paint room. The only ventilation present is a ceiling fan in each room that is used for general dilution ventilation.
Note: Because of specifications from their client, substitution is not a viable control method for either the welding or painting operations.
An industrial hygienist (IH) recently conducted air monitoring at the facility. In the welding bays, the IH conducted initial monitoring with a personal sample collected on each welder and analyzed for hexavalent chromium (Cr+6). The results showed that time weighted average (TWA) exposures were 6.2 micrograms per cubic meter (μg/m3) and 6.6 μg/m3. The OSHA TWA PEL is 5 μg/m3 with an action level of 2.5 μg/m3.
The paint area uses primer and paint containing benzene, ethyl benzene, toluene, and xylene. Workers in the area also use acetone on rags to clean surfaces. One employee was sampled for the entire work shift. A second employee was sampled for 15 minutes (STEL sample) while cleaning with the acetone and for 15 minutes (STEL sample) while mixing the primer and paint. The table below summarizes the results of the sampling, along with the applicable permissible exposure limits (PELs) established by OSHA and the guidelines (threshold limit values or TLVs) published by the American Conference of Governmental Industrial Hygienists (AGGIH).
Analyte Sample Type Analytical Results OSHA PEL ACGIH TLV TWA STEL TWA STEL
Benzene
TWA
STEL
12 ppm
25 ppm
1 ppm
5 ppm
0.5 ppm
2.5 ppm
Ethyl Benzene
TWA
STEL
20 ppm
35 ppm
100 ppm
NE
20 ppm
NE
Toluene
TWA
STEL
15 ppm
30 ppm
200 ppm
500 ppm (10 min.)
20 ppm
NE
Xylene
TWA
STEL
24 ppm
36 ppm
100 ppm
NE
100 ppm
150 ppm
Acetone
TWA
STEL
14 ppm
124 ppm
1000 ppm
NE
200 ppm
500 ppm
ppm = parts per million
NE = None Established
II. The Scenario
You have been hired by Acme International to evaluate the work areas, recommend controls, design the controls, and install the controls.
III. Assignment
1. Analyze the hazards in both areas of the facility using one of the methods described in Chapter 3 of the textbook. You should identify at least two hazards in each area (welding and painting).
2. Perform a risk assessment on at least two hazards in each area using the 4X4 matrix in Table 17-3 of the textbook.
3. Prioritize the need for controls for the hazards you selected based on the results of the risk assessment.
4. Using the hierarchy of engineering controls listed on page 420 of the textbook, recommend a control method for each hazard that you believe would be the most effective in reducing risk to an acceptable level. Use the 4X4 matrix to show the reduction in risk for each hazard. Note: At least one control method must be a local exhaust ventilation (LEV) system.
5. For the LEV, specify the hood configuration, a recommended capture velocity, and a recommendation for treatment of the exhaust stream. Explain why you made the choices and support your decisions with at least one reference other than the text.
6. Discuss how Prevention through Design could be used to reduce the risks associated with these operations if you were hired to design a new facility performing these same activities from scratch.
Prepare your paper in a properly formatted APA document, including a title page, a brief abstract section, the body of the paper, and a reference page. The body of your paper must be a minimum of four pages in length and double-spaced (title page, abstract, and reference page do not count toward the four-page minimum). You must use your textbook and at least one other source.