the subject: Occupational Hygiene and chemical
the information has been provided through documents
OCHS2000 Final Assessment
In this assessment you are required to prepare a report based on your assessment of 5 different scenarios, involving a variety of hazards. The report should contain a general introduction, discussing the importance of occupational hygiene in OHS and briefly mention each of the following scenarios. Each scenario should then be included in its own section in the report. There is a word limit of 2500 words.
Scenario 1 – Styrene Monitoring
Styrene is a commercially important chemical, used in the manufacture of polystyrene foams, ABS plastic, and a variety of rubbers and thermosetting resins. It is also carcinogenic, with inhalation and absorption through the eyes and skin being significant routes of exposure. Discuss the potential health effects, both acute and chronic, of styrene exposure.
You plan to monitor a number of workers for 4 hours each using personal sampling in accordance with NIOSH 1501. If the limit of detection for styrene using is 0.4 µg/sample, and previous monitoring at the site indicated levels of 0.21 mg/m3, how long would you need to sample at a flow rate of 500 mL/min to detect this concentration? Would this be reasonable? If not what flowrate would you propose? Explain your reasoning.
Scenario 2 – Dust Sampling
Respirable crystalline silica represents a significant hazard to workers. A mine with significant amounts of silica present has requested an assessment be done on their workers. This assessment is interested in determining individual worker exposure. The average silica content in the dust is 23%, you may assume this is applicable to all measurements.
After 12 hours (a single shift) of sampling, the following masses of respirable dust were collected.
Worker Mass of Dust (µg)
Crusher Operator 2009
Mechanic (1) 589
Mechanic (2) 507
Site based Administration Officer 17
Health and Safety Advisor 123
Calculate the average airborne respirable dust concentration for each worker, and compare to the OES for both respirable dust and crystalline silica.
Based on the results of your calculations discuss any potential issues with exposure and any potential actions which may be required.
Scenario 3 – Noise
A carpenter is involved in a significant construction job, part of their work is to prefabricate a series of wooden panels that will form part of the ceiling at a new concert hall. The job involves cutting engineered wood panels to the prescribed size using a table saw. As the duration of the cut depends on the size of the panel, an LAeq measurement is taken of several minutes to capture the loading and unloading of panels and a series of cuts. This measurement results in an LAeq value of 93 dB(A). Comment on the representativeness of this measurement and determine the carpenter’s equivalent 8 hour exposure if they perform the task for 4.5 hours, and have no other significant noise exposure. Based on this result what recommendations would you make?
Scenario 4 – Chemical Spill
A small laboratory with dimensions 4 x 5 x 2.5 m is used to prepare a range of crude oil samples for analysis via GC-MS. For one such preparation a small quantity of dichloromethane (DCM) is used to help separate polar and non-polar fractions from the oil sample using chromatography columns. A single 5 L bottle of high purity DCM is stored in the laboratory, with smaller working volumes directly decanted from the bottle as needed. Briefly comment on the requirements for safe storage of DCM and any requirements for handling a spill during work.
If a worker in the lab decanted 450 mL of DCM into a beaker and left the laboratory urgently, without safely storing the decanted DCM, and the laboratory was closed over the weekend, what would be the concentration of DCM in the laboratory air the following week (you may assume complete evaporation, and no ventilation)?
If the LEL of DCM is 13%, would this value be exceeded?
If the IDLH value is 2300 ppm, is there an immediate danger to a worker entering the lab?
Scenario 5 – Controls
In an underground mine there are a variety of diesel powered vehicles in use. Many of these are old and have been in use for a considerable length of time. The mine is mechanically ventilated, though is very hot and humid in a number of locations and has many dead end passages where the air circulation is poor. There is a concern about worker exposure to diesel particulate matter (DPM) in the mine. A monitoring study was conducted when the mine was operating at 60% capacity found that several workers were being exposed to DPM concentrations above the AIOH recommended level. Discuss possible control measures, within the context of the hierarchy of controls. Which of the measures you have discussed, would you recommend be implemented, and why?
When completing this assessment…
Ensure you show your working for all calculations, as part marks may be available if the correct method/formula has been used, and the answer is incorrect. You will be expected to justify your answers using relevant standards, legislation, guidance notes and codes of practice.
Criterion Marks Available
Use of appropriate report structure
(e.g. cover page, contents page, introduction, separate sections for each scenario, conclusion). 1
Discusses the importance of occupational hygiene to OHS and introduces each of the scenarios. 4
The necessary calculations are performed and working shown. Health effects of styrene exposure are described. Use of appropriate literature. 7
The necessary calculations are performed and working shown. The potential implications of the result are discussed, along with any potential limitations. Use of appropriate literature. 7
The necessary calculations are performed and working shown.
Recommendations are suitable. Use of appropriate literature. 6
The necessary calculations are performed and working shown. Requirements for safe storage and the handling of spills are provided. Use of appropriate literature. 7
Suitable controls are discussed within the context of the hierarchy of controls. The recommended controls are practical. Use of appropriate literature. 6