Hazards

Question 1

What is OSHA’s allowable duration of noise exposure

Answer 1

8 hours TWA at 90dBA

cut time in half for each 5dB increase in noise level

Question 2

What is the hearing requirement on audiogram for DOT drivers

Answer 2

Must not have an average hearing loss greater than 40dB at the 500, 1000 and 2000Hz, with or without a hearing aid

Question 3

List decibel range for each degree of hearing loss:

Normal
Mild Hearing Loss
Moderate Hearing Loss
Severe Hearing Loss
Profound Hearing Loss

Answer 3

Degrees of Hearing Loss

Normal:    -10 to 25 dB
Mild:           30 to 45 dB
Moderate:  50 to 65 dB
Severe:      70 to 85  dB
Profound:   >90 dB

Question 4

What is the x and y axis of an audiogram and what do they signify

Answer 4

x axis: kHz is the TONE (frequency) of a sound

y axis: dB is the INTENSITY of a sound

Question 5

meaning of speech occurs at what frequencies

Answer 5

500-3000Hz

Question 6

What dB of noise can lead to TM rupture

Answer 6

180dB

Question 7

What pattern would you expect on an audiogram when CONDUCTIVE HEARING LOSS is present

Answer 7

low frequency hearing loss at all frequencies or a “flat” line on audiogram

Question 8

List some causes of Sensorineural Hearing Loss

Answer 8

• Heavy Metals (arsenic and Pb)
• Noise induced
• age related

Question 9

At what frequency do you expect to see Noise-Induced Hearing Loss

Answer 9

4,000-6,000Hz

Question 10

Describe the difference between Age-Related and Noise-Induced Hearing loss on audiogram

Answer 10

Age-related will show changes at all levels whereas Noise-induced will show a dip at 4,000Hz and then a slight recovery at higher frequencies

Question 11

At what noise level does OSHA require a Hearing Conservation Program?

Answer 11

85dBA over an 8 hour period

Question 12

OSHA Hierarchy of Controls

Answer 12

Elimination
Substitution
Engineering
Administrative
PPDs

Question 13

Permissible vs actionable noise level

Answer 13

Permissible is 90dB over 8 hour shift

Hearing Program must be put in place if 8 hour weighted average is 85dB

Question 14

Define a Standard Threshold Shift in a Hearing Conservation Program

Answer 14

if the average dB over 2kHz, 3kHz and 4kHz decreases greater than 10dBA compared to baseline, then an STS has happened

Question 15

At what level does a Noise-Induced Standard Threshold Shift (STS) become recordable

Answer 15

if the average change over baseline at 2kHz, 3kHz, 4kHz) is above 25dBA

Question 16

List the 4 types of Ionizing Radiation

Answer 16

• Alpha particles
• Beta particles
• Gamma particles
• Neutrons

Question 17

Which type of ionizing radiation does NOT penetrate the skin but is dangerous if ingested?

Answer 17

Alpha particles

Question 18

List the 4 types of NONionizing radiation

Answer 18

• Radiofrequency
• Microwave
• Infrared
• Ultraviolet

Question 19

What are the types of UV Radiation and how are they subdivided

Answer 19

UV Radiation is subdivided by wavelength

UV-A: long
UV-B: medium
UV-C short

Question 20

Give examples of occupational UV exposure and consequence

Answer 20

Sun: burns and dermatitis

Welding: arc/flash burns to the cornea