OSHA defines an excavation as any man-made cut, cavity, trench, or depression in the earths surface formed by earth removal. A trench is defined as a narrow underground excavation that is deeper than it is wide, and is no wider than 15 feet (4.5 meters). Dangers of Trenching and Excavation. Cave-ins pose the greatest risk and are much more likely than other excavationrelated accidents to result in worker fatalities.
How long does a typhoid shot last?   According to the CDC website, a booster dose is needed every 2 years for people who remain at risk.. The oral (live) vaccine lasts 5 years before another dose is neededâ¦.
Report Abuse. Where I live there are 1 year and 3 year shots. For the first shot a 1 year is given or if the 3 year one expires before another one is given you have to have a 1 year shot. Otherwise it is a 3 years shot. Your rabies certificate should say when the shot expires. rabies shot last for one year, however, if they are bit by a rabid animal in that time, they may need a booster shot as well at that time.