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¦.
Live typhoid vaccine (oral). 1  Four doses: one capsule every other day for a week (day 1, day 3, day 5, and day 7). 2  The last dose should be given at least 1 week before travel to allow the vaccine time to work. 3  Swallow each dose about an hour before a meal with a cold or lukewarm drink.ive typhoid vaccine (oral). 1  Should not be given to children younger than 6 years of age. 2  Anyone who has had a severe reaction to a previous dose of this vaccine should not get another dose. 3  Anyone who has a severe allergy to any component of this vaccine should not get it.