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¦.
The last dose should be given at least. 1 week before travel to allow the vaccine time to. work. â¢A booster dose is needed every 5 years for people. who remain at risk. Either vaccine may be given at the same time as. other vaccines. There are two vaccines to prevent typhoid. One is. an inactivated (killed) vaccine gotten as a shot, and. the other is live, attenuated (weakened) vaccine. which is taken orally (by mouth). 2 Typhoid vaccines. 4 Some people should not get. typhoid vaccine or should wait.