ASP Advanced Sciences and Mathematics for Safety

Question 1

A workplace noise survey records the following daily exposures: 90 dBA for 4 hours, 95 dBA for 2 hours, and 100 dBA for 1 hour.
Using OSHA's permissible exposure limits (PEL) and the dose equation D = (C1/T1 + C2/T2 + C3/T3), what is the noise dose?

Accepted Answer

D = 1.25 (exceeds PEL)

Answer

D = 0.75 (within PEL)

Answer

D = 1.00 (exactly at PEL)

Answer

D = 0.50 (well within PEL)

Question 2

A chemical has a TWA-TLV of 50 ppm. Air sampling over an 8-hour shift yields the following results: 60 ppm for 3 hours, 40 ppm for 3 hours, and 55 ppm for 2 hours. What is the 8-hour TWA concentration?

Accepted Answer

51.25 ppm — exceeds the TLV

Answer

50.00 ppm — exactly at the TLV

Answer

48.75 ppm — below the TLV

Answer

55.00 ppm — equals the highest sample

Question 3

In toxicology, the LD50 value of a substance is used to:

Accepted Answer

Compare the relative acute toxicity of substances on a standardized basis

Answer

Determine the concentration at which 50% of exposed workers will develop cancer

Answer

Set OSHA permissible exposure limits for air contaminants

Answer

Calculate the lethal dose for a specific individual based on body weight

Question 4

A safety professional needs to calculate the dilution ventilation required to control a solvent with an evaporation rate of 1 pint/hour. The solvent has a specific gravity of 0.88 and a molecular weight of 92. The TLV is 100 ppm. Using the standard dilution ventilation formula, approximately how many cubic feet per minute (CFM) of fresh air are needed (using K=10)?

Accepted Answer

Approximately 11,300 CFM

Answer

Approximately 1,130 CFM

Answer

Approximately 5,650 CFM

Answer

Approximately 22,600 CFM

Question 5

A fault tree analysis assigns the following probabilities: Event A = 0.10, Event B = 0.05. If these two events are connected by an AND gate, what is the probability of the top event occurring?

Accepted Answer

0.005

Answer

0.15

Answer

0.005 or 0.15 depending on dependency

Answer

0.50

Question 6

Which statistical distribution is most appropriate for modeling the time between random, independent equipment failures (exponential failure rate)?

Accepted Answer

Exponential distribution

Answer

Normal (Gaussian) distribution

Answer

Binomial distribution

Answer

Poisson distribution