Please review the entire project prior to accepting this requires completion on the designated template provided

As the environmental health and safety (EHS) manager, you have been asked to evaluate an existing operation to determine employee’s current exposure to hexane, which is a chemical used in painting processes.
You are to complete an evaluation of the employee’s current exposure by determining the employee’s exposure to hexane (toxic contaminant) by calculating time-weighted average (TWA) and compare it to the permissible exposure limit (PEL) and modify the PEL, if necessary. If it is necessary to modify the PEL, explain the reasoning why it is to be modified. Once the current exposure has been determined, select the appropriate ventilation system between dilution and local exhaust that is the best choice to control the concentration of the contamination. Ensure that you provide the reasons why you think your selection of ventilation system is the best choice. You are to provide the results in a three-page project report using the Unit III Consulting Report template .

Please see scenario that HAS to be used in the attachments

ANSWER

Unit III Project

Executive Summary

Hexane, an organic compound, is a constituent of gasoline. It consists of six carbon atoms and can harm the body if an employee is exposed to it for long durations. The scenario at Be Safe Consulting, Inc. represents typical problems associated with exposure to the chemical. To expand on the health effects of exposure to hexane, the report calculated the total-weighted average concentration of the chemical, the permissible exposure limit, the dilution ventilation, and local exhaust ventilation capture velocity. The findings determined that an employee’s total-weighted average hexane concentration for a 9-hour shift is 420.28 ppm. The permissible exposure limit is 444.44 ppm. The capture velocity for the dilution ventilation is 5 fpm. The capture velocity for the local exhaust ventilation is 4 fpm.

 

On March 24, 2018, Be Safe Consulting, Inc. entered a contract to perform the following services:

1. Conduct sampling and analysis for the amount of hexane inhaled by an employee working a 9-hour shift at a painting company.
2. Provide ventilation measurements on booth exhaust airflow
3. Determine the room air changes per hour in a 300ft² room to determine the need for additional ventilation.

Methodology

The study relied on the calculations for the Total Weighted Average using the formula:

Where:

C_n = Concentration

T_n = Time

Also, the study relied on the calculations for Permissible Exposure Limit using the formula:

PEL_{n hours} =

Finally, the study relied on the calculations of the ventilation systems (dilution ventilation and local exhaust ventilation) using the formula:

Where:

V= velocity (fpm)

Q = flow rate (cfm)

X = source distance from the hood opening (ft)

A = area (ft²)

 

Findings

The TWA calculations determined that the time-weighted average concentration of hexane in the room is within the 9-hour shift is 420.28 ppm. The calculated permissible exposure limit for hexane within a 9-hour shift is 444.44ppm. The dilution ventilation airflow resulted in 4.651 fpm. The calculation for the local exhaust ventilation was 3.953 fpm.

The results of the samples are as follows:

Calculation Results

Contaminant	Concentration (Time-Weighted Average)	PEL
Hexane	420.28 ppm	444.44 ppm

Results of Option #1 Ventilation System: 4.651 fpm

Results of Option #2 Ventilation System: 3.953 fpm

Discussion

The employee’s exposure to hexane during the 9-hour shift is 420.28 ppm, while the modified permissible exposure limit is 444.44 ppm for the 9-hour shift. Comparing these numbers, a conclusion is reached that the employee’s exposure does not exceed the PEL. Therefore, it is unnecessary to reduce the employee’s overall exposure. However, Be Safe Consulting can apply various methods to reduce the employee’s general exposure to hexane. The methods include administrative controls that limit the employee’s working time to eight hours per shift, identifying solvents to absorb hexane, and removing the chemical using mechanical ventilation. Since the employee’s exposure to hexane within the 9-hour shift is within the permissible exposure limit, Be Safe Consulting, Inc. does not additional interventions to limit exposure.

However, the dilution ventilation fails to meet the required 20 room air changes per hour. It returns a capture velocity of 4.65 or 5 fpm, which is lower than the 90-fpm standard capture velocity. Therefore, the dilution ventilation must be modified. Also, the local exhaust ventilation returned a capture velocity of 3.95 or 4 fpm. The value is lower than the required 140 fpm. Therefore, the ventilation must be modified.

Summary and Conclusions

The report focused on the airflow of Be Safe Consulting, Inc. It relied on calculations of the total-weighted average of hexane and the permissible exposure limit of the chemical in a 300ft² room. Also, it calculated the airflow resulting from a dilution and local exhaust ventilation. In the findings section, the report captured the data in a table format. The discussion section addresses the need for or against taking measures to reduce exposure to hexane and to modify the ventilation.

The paper recommends the following:

1. Since the general exposure to hexane does not exceed the permissible exposure limit, Be Safe Consulting, Inc should retain its current working shift.
2. Since Be Safe Consulting, Inc requires at least 20 air room changes per hour, it should modify its dilution ventilator to increase its capture velocity.
3. Since Be Safe Consulting, Inc. requires its local exhaust ventilation to produce at least 140 fpm, it should modify its local exhaust ventilators since the 4 fpm it achieves is low.

 

 

 

 

References

Brande, D. E., Milholland, D. C., & Haycocks, N. R. (2020, September 1). Why is 90 FPM considered standard for cleanroom airflow? ISPE. Retrieved February 28, 2022, from https://ispe.org/pharmaceutical-engineering/march-april-2017/why-90-fpm-considered-standard-cleanroom-airflow#:~:text=In%20December%201963%2C%2090%20fpm,(within%20%C2%B120%20fpm).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Appendix A – Calculations for Time-Weighted Average

Where:

C_n = Concentration

T_n = Time

= 420.278 ppm

 

 

 

Appendix B– Calculations for Permissible Exposure Limit (Modification)

PEL_{n hours} =

The 8-hour PEL for hexane = 500 ppm

PEL_{12 hours} =

PEL_{12 hours} =

PEL_{12 hours} = 444.44 ppm

 

 

 

 

Appendix C – Calculations for Option #1 Ventilation System

(Dilution Ventilation)

Where:

V= velocity (fpm)

Q = flow rate (cfm)

X = source distance from the hood opening (ft)

A = area (ft²)

Calculation for Area

A = L × W

15ft × 20ft

= 300ft²

Therefore;

 

 

 

Appendix D – Calculations for Option #2 Ventilation System

(Local Exhaust Ventilation)