FACTS

The most dangerous forms of construction work involve trenching and shoring.

1. Trench cave-ins and collapses. Trench collapse, or cave-in, was the most frequent cause of fatal occupational injury in the confined spaces category of ditches, channels, trenches and excavations.
2. Falls into excavations and falling loads. Workers and work equipment or materials falling into trenches represents a safety hazard.
3. Hazardous atmospheres in trenches. Not only can excavated areas sometimes have diminished oxygen levels, but a trenched area’s atmosphere can also be contaminated with toxic gases and chemicals.
4. Mobile equipment on the construction site. Accidents on the construction site, with vehicles like dump trucks or backhoe loaders, are also one of the common excavation hazards.
5. Hitting utility lines while excavating. Trenching hazards also include electrocution and natural gas leaks from hitting utility lines.

STATS

• Bureau of Labor Statistics data show that about 25 workers are killed each year in trench-related mishaps.  Cave-ins cause about three out of every four fatalities; the remainder are commonly due to struck-by or electrocutions.
• The main reason trenches collapse is that they are not properly protected.  Protective systems were properly employed in only 24 % of the trenches.  In the remainder, a protective system was either improperly used (24%), available but not in use (12%) or simply unavailable (64%).
• Despite the fact that environmental conditions were a contributing factor in 68 % of the fatalities, the competent person was not onsite when the fatality occurred 86 % of the time.  Most of the time (65%) the employer had not identified the soil type even though soil type is a factor in trench cave-ins.
• A disproportionate number of fatalities (36%) occurred on Mondays, because rain or other factors changed conditions over the weekend.
• The OSHA investigations showed that schedule time was more important than safety in 88 % of the incidents. 72 % of the fatalities occurred in trenches less than 9 feet deep.  Only nine percent occurred deeper than 15 feet.
• Just over half the employers had a written safety and health program, but, of these, only 40 % covered trenching.  65 % provided no trench safety training.  Most employers (71%) had never been inspected by OSHA, but 21 % had been previously cited by OSHA for trench safety violations.
• About three in every four fatalities occurred at residential worksites.  Most companies were small; 42 % had fewer than 10 employees.  Though, typically, five or less workers were present on the site when the incident occurred, most of the projects (52%) involved contracts worth $100,000 or more.