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- QUESTION
You are asked to evaluate employees’ exposures to methyl n-amyl ketone during a painting operation. After careful consideration, you choose NIOSH Method 2553 for the sampling. You can access the method by clicking the link below:
National Institute for Occupational Safety and Health. (2003). Ketones II: Method 2553. In P. M. Eiler & M. E. Cassinelli (Eds.), NIOSH manual of analytical methods (4th ed.). Retrieved from http://www.cdc.gov/niosh/docs/2003-154/pdfs/2553.pdf
Your pre-sampling and post-sampling pump calibrations using a primary standard are both 0.05 L/min. You collect personal samples on two employees working in the operation. The samples are collected for 430 minutes (Sample 1) and 440 minutes (Sample 2).
Calculate the sample volumes for each of the samples.
The laboratory reports that the front section of Sample 1 contains 5,000 µg of methyl n-amyl ketone and the back section contains 200 µg of methyl n-amyl ketone. The front section of Sample 2 contains 4,000 µg of methyl n-amyl ketone and the back section contains 50 µg of methyl n-amyl ketone. Neither the front nor back sections of the field blank you supplied contain any detectable levels of methyl n-amyl ketone.Calculate the concentrations of the two personal samples in µg/L and mg/m³.
Convert the result to ppm (MW for methyl n-amyl ketone = 114.2). Note: Use the ideal gas constant of 24.45.
Show all the steps for your calculations.
You then reference OSHA’s Table Z-1 and find that the 8-hour TWA PEL for methyl n-amyl ketone is 100 ppmDiscuss how the results of the two personal samples you collected compare to the OSHA PEL, and describe the sampling method you implemented.
You also look up the ACGIH TLV for methyl n-amyl ketone and find that the TLV is 50 ppm as an 8-hour TWA exposure.Discuss how the results for the two personal samples compare to the ACGIH TLV.
Discuss whether you would recommend comparing the results of your sampling to the OSHA PEL or the ACGIH TLV. Include your rationale for the choice, and explain how you would rationalize your choice to your employer.
The case study should be a minimum of three pages in length, and you should cite the NIOSH document using APA style.
| Subject | Business | Pages | 5 | Style | APA |
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Answer
Industrial Hygiene Case Study
Sample Volumes Calculation
The case study reveals that the pump calibrations utilized for the pre and post-sampling pumps relied on a primary standard of 0.05L/Min.
The first sample’s sampling time is 430 minutes
The second sample’s sampling time is 440 minutes.
Volume = Rate * Time
Sample 1 Volume = 0.05L/Min * 430 minutes = 21.5 L
Sample 2 Volume = 0.05L/Min * 440 minutes 22 L
Personal Samples Concentrations
Based on the provided laboratory reports, it is evident that the front section of Sample 1 is composed of 5,000 µg of methyl n-amyl ketone while the back section is composed of 200 µg of methyl n-amyl ketone. Sample 2’s front section is composed of 4,000 µg of methyl n-amyl ketone while the back section was composed of 50 µg of methyl n-amyl ketone.
The value of the analytes as present at different locations of the samples
The value at the front section of Sample 1 is 5000 µg (Wf)
Back section value of Sample 1 is 200 µg (Wb)
The value at the front section of Sample 2 is 4000 µg (Wf)
Back section value of Sample 2 is 50 µg (Wb)
The fact that the field blank supplied did not contain any visible amounts of methyl n-amyl ketone suggests that the allocated value at the front and the back end is O. (Front section value is 0 (Bf) while the back section value is 0 (Bb).
The personal sample concentration is achieved through the formula:
Concentration = (Wf + Wb –Bf – Bb)/V = mg/m3
First Sample’s concentration:
5000 + 200 – 0 - 0/21.5 = 241.86 microgram/m3
Therefore, the achieved concentration value for sample 1 is 241.86 microgram/L
Second sample’s concentration:
4000 + 50 – 0 - 0/22 =184.09 microgram/m3
Therefore, the achieved concentration value for sample 2 is 184.09 microgram/L
Conversion to ppm
The conversion process is achieved through the formula:
24.45 * TLV existing in mg/m3/molecular weight
Therefore, to convert the value for the first sample:
24.45 * (241.86/114.2)
The obtained value is 51.78ppm.
For Sample 2:
24.45 * (184.09/112.4)
The obtained value is 39.41ppm
Discussing the Findings
Looking at the obtained findings after the sampling process, it is evident that the figures are below the permitted values of exposure as outlined by the Occupational Safety and Health Administration (OSHA) as a limit of 100ppm (National Institute for Occupational Safety and Health (NIOSH), 2003) Therefore, the company seems to be in compliance with the OSHA requirements by conforming to the presented value. As a result, it is recommended that the NIOSH method 2553 should be utilized to determine the conformance while considering the safety of the employees. Moreover, it is a fact that the exposure limit of methyl n-amyl ketone is equivalent to the OSHA PEL value. The NIOSH Method 2553 implemented for the process of sampling involves the use of a solid sorbent tube utilized to trap and retain the compound of interest without making any changes to the composition of the substance. In the case study, two samples were identified for 430 minutes and 440 minutes respectively, each with a flow rate of approximately 0.05 liters per minute. Subsequently, it is evident that a 2% isopropanol solution available in carbon disulfide was utilized to release the available methyl n-amyl ketone from the sorbent (NIOSH, 2003).
Comparison to the to the ACGIH TLV
The results obtained after the sampling process is close to the exposure limit which is provided by the American Conference of Governmental Industrial Hygienists (ACGIH). Despite this, it is a fact that the value obtained for Sample 1 is slightly higher than the set limit. Therefore, if relying on the limits provided by the ACGIH, the firm and industry should be investigated further to establish it the players comply with the set industrial values to observe the safety of the employees. However, this recommendation may not be applicable if relying on the OSHA PEL values.
I would advise that the sampling results be compared to the ACGIH TLV rather than the OSHA PEL. The fact that the generated values after the sampling procedure provides a depiction that the values are below the permissible limits of exposure as outlined under the OSHA requirements. The generated results obtained from the collected samples produced much lower results than the set ACGIH threshold and limit figure for the methyl n-amyl ketone. Therefore, it can be derived that the work site is safe and suitable for the members of the workforce. However, it is advisable that the obtained results from the sampling process should be compared to the ACGIH TLV based on the fact that it is more stringent in comparison to the OSHA PEL. By abiding by the stricter limit the firm will be in a position to abide by the set legal limits which does not jeopardize the health and safety of the employees. Additionally, following the stricter limits also provides a guarantee that the firm will be operating with within the legally enforced limits. Providing the safety of the members of the workforce is a priority for any business which want to avoid litigations in the future.
References
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National Institute for Occupational Safety and Health. (2003). Ketones II: Method 2553. In P. M. Eiler & M. E. Cassinelli (Eds.), NIOSH manual of analytical methods (4th ed.). Retrieved from http://www.cdc.gov/niosh/docs/2003-154/pdfs/2553.pdf
Appendix
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