The five most common causes of workplace accidents in the United States are overexertion, contact with objects or equipment, falls, exposure to harmful substances, and transportation incidents. Together, these five categories account for the vast majority of injuries that force workers to miss time, switch to lighter duties, or transfer to a different role. Bureau of Labor Statistics data from the 2023-2024 reporting period recorded over 2.8 million such cases from these causes alone, and the National Safety Council estimates that work-related injuries cost the nation nearly $1.2 trillion in 2022.
1. Overexertion and Repetitive Motion
Overexertion is the single largest driver of workplace injuries, responsible for 946,290 cases requiring time away or restricted duties during the 2023-2024 period. These injuries happen when the body is pushed beyond its limits through lifting, pulling, pushing, carrying, or performing the same motion repeatedly. The resulting damage typically shows up as muscle strains, low back injuries, rotator cuff tears, tendinitis, carpal tunnel syndrome, and trigger finger.
What makes overexertion injuries especially costly is that they tend to build over time. A warehouse worker lifting boxes might not feel a problem for weeks or months before a back injury sidelines them. An office worker typing eight hours a day can develop wrist pain that gradually becomes debilitating. OSHA notes that musculoskeletal disorders from overexertion are among the most frequently reported causes of lost or restricted work time across all industries. The good news: applying ergonomic principles, such as redesigning workstations, using mechanical lifts, and rotating tasks, can substantially reduce both the number and severity of these injuries.
2. Contact With Objects and Equipment
Being struck by, caught in, or compressed by objects and equipment caused 860,050 injury cases in the 2023-2024 period, making it the second most common cause. This category covers a wide range of scenarios: a tool falling from scaffolding, a hand getting caught in a conveyor belt, or a worker being hit by a forklift rounding a blind corner.
Construction sites are particularly high-risk. NIOSH survey data breaks down the main causes of struck-by injuries in construction: 36% involve working around heavy equipment or vehicles, 30% come from falling or flying objects during work at heights, and 19% result from objects falling or flying at ground level. Even something as simple as a wrench slipping off a truck bed can cause a serious injury. “Struck-by” is one of OSHA’s “Focus Four” hazards in construction, the categories responsible for the most fatalities in that industry. Prevention centers on securing tools and materials at heights, maintaining clear communication around heavy equipment, and wearing hard hats and other protective gear in designated areas.
3. Falls, Slips, and Trips
Falls, slips, and trips accounted for 721,720 cases in the 2023-2024 BLS data, ranking third overall. CDC data from 2020 found that 18% of all nonfatal injuries resulting in days away from work were related to this category. Falls from heights, such as ladders, roofs, and scaffolding, tend to produce the most severe injuries, but same-level falls from wet floors, uneven surfaces, cluttered walkways, and loose cables are far more frequent.
Falls are also one of OSHA’s Focus Four construction hazards and consistently rank among the top causes of workplace fatalities. The gap between fatal and nonfatal patterns matters here: while overexertion causes far more total injuries, falls are disproportionately deadly. If you work at heights, fall protection systems like guardrails, safety nets, and personal harnesses are the primary line of defense. For same-level falls, the fixes are often straightforward: prompt cleanup of spills, proper lighting, anti-slip flooring, and keeping walkways clear of cords and debris.
4. Exposure to Harmful Substances
Exposure to harmful substances or environments caused 224,450 cases during the 2023-2024 period. This category includes inhaling toxic fumes, skin contact with chemicals, extreme temperatures (both heat and cold), oxygen-deficient environments, and electric current. Industries like manufacturing, agriculture, mining, and healthcare see these injuries most often.
The injuries in this category vary enormously in severity. A mild chemical burn from a cleaning product might mean a few days of restricted duty, while inhaling concentrated fumes in a confined space can be fatal. Electrocution is another subset here and is serious enough to earn its own place in OSHA’s Focus Four construction hazards. Prevention follows what safety professionals call a hierarchy of controls: first, try to eliminate the hazard entirely; if that’s not possible, substitute a less dangerous material; then use engineering controls like ventilation systems; then adjust work practices such as limiting exposure time; and finally, provide personal protective equipment like respirators, gloves, and insulated gear.
5. Transportation Incidents
Transportation incidents round out the top five with 121,330 cases in the 2023-2024 data. These involve vehicle crashes, collisions, and other incidents on roads, highways, or within work premises. While this category produces the fewest nonfatal injuries of the five, it is the leading cause of workplace fatalities year after year. Delivery drivers, truck drivers, ride-share operators, and anyone who drives as part of their job faces elevated risk.
The severity gap is stark. A transportation incident is far more likely to kill a worker than an overexertion injury is. That’s why fleet safety programs, distracted driving policies, vehicle maintenance schedules, and seatbelt requirements are standard across industries where employees spend time on the road.
The Role of Fatigue Across All Categories
One factor that cuts across every category on this list is fatigue. The National Safety Council reports that 13% of workplace injuries can be attributed to fatigue, and the problem is widespread: 97% of workers have at least one fatigue risk factor, more than 80% have two or more, and over 37% of employees are sleep-deprived. A fatigued worker is more likely to misjudge the weight of a load, miss a wet floor sign, lose focus around heavy machinery, or react slowly behind the wheel. Adequate rest breaks, reasonable shift lengths, and attention to scheduling are some of the most effective ways employers can reduce injuries across the board.
What These Injuries Cost
The financial toll is staggering. Liberty Mutual’s 2025 Workplace Safety Index estimates that employers pay more than $1 billion per week in direct workers’ compensation costs for disabling, nonfatal injuries. That figure only covers direct costs like medical bills and wage replacement. When you factor in indirect costs, including lost productivity, hiring and training replacements, equipment damage, and administrative time, the total reaches much higher. The National Safety Council’s estimate of $1.2 trillion in 2022 captures this fuller picture.
For individual workers, the impact goes beyond money. Median days away from work vary by injury type, but overexertion and fall injuries frequently mean weeks or months of recovery. Some injuries, particularly severe back injuries, repetitive strain disorders, and traumatic brain injuries from falls, can permanently limit what a person is able to do at work and in daily life.