The OSHA regulation at 29 C.F.R. §1910.1000(d) requires employers to determine the cumulative exposure of workers to certain gases over an 8-hr work shift using the following formula:
E = CaTa + CbTb + .... + CnTn 8
E is the equivalent exposure for the work shift, C is the concentration during any period of time in which the concentration remains constant, and T is the duration of time in hours of the exposure.The regulation further stipulates that no employee can be further exposed to the gas when the value of E exceeds the 8-hr time-weighted average limit set for the given substance. If a worker is exposed to ammonia concentrations throughout the workday as follows, 125 ppm for 4 hr; 75 ppm for 2 hr; and 25 ppm for 2 hr, determine the equivalent exposure (E):
Using a pulse CO-oximeter, a paramedic establishes that the blood of an on-duty fire fighter contains carboxyhemoglobin at a concentration of 55,000 ppm by volume. What would be the symptoms?
Below is a list of chemicals with their oral LD50 in mg/kg (rats). Select the substance that is MOST toxic to rats.
Which health effect is manifested when an injury or disease occurs only after an extensive period of time?
Aflatoxins are natural chemicals found in certain forms of mold that can grow on rice, grains, nuts and seeds, legumes, and spices like black pepper. Continued exposure to aflatoxins has been linked to liver damage in some individuals. What do you call a substance that can cause liver damage?