In health and safety, a risk is the chance that someone will be harmed when exposed to a hazard. It combines two factors: how likely the harm is to happen, and how serious that harm could be. This is different from a hazard, which is the thing that could cause damage. A wet floor is a hazard. The probability that someone slips on it and breaks a wrist is the risk.
Risk vs. Hazard
These two terms get used interchangeably in everyday conversation, but they mean different things in workplace safety. A hazard is any source of potential damage, whether that’s a chemical, a piece of machinery, a height, or even a pattern of work. Risk is the likelihood that the hazard actually causes harm, combined with how severe that harm would be. Smoking is a hazard. The probability of developing lung cancer from smoking is a risk.
This distinction matters because not every hazard carries the same level of risk. A sharp knife in a locked drawer poses far less risk than the same knife on a busy kitchen counter. The hazard is identical. The risk changes based on who is exposed, how often, and under what conditions.
Types of Workplace Risk
Most people think of physical dangers when they hear “health and safety risk,” but the category is much broader than falling off a ladder.
Physical risks include falls, vehicle incidents, machinery contact, and exposure to noise or vibration. Transportation incidents remain the leading cause of workplace fatalities in the United States, accounting for 38.2 percent of all occupational deaths in 2024 (1,937 fatalities). Falls, slips, and trips caused 844 deaths that same year.
Ergonomic risks come from how work physically loads the body. The key factors are the force required, how often a movement is repeated, the duration of exposure, and the posture involved. A worker who spends more than half a year performing high-intensity repetitive tasks at awkward angles faces a very different risk profile than someone doing the same task for a few days. Assessors score these factors on scales that account for intensity, duration, and how well the worker’s body has adapted to the load.
Chemical and environmental risks involve exposure to harmful substances, from cleaning solvents to airborne dust to extreme temperatures. In 2024, exposure to harmful substances or environments caused 687 workplace fatalities in the U.S., down from 820 the year before.
Psychosocial risks are increasingly recognized as genuine safety concerns. These include chronic work overload, inadequate staffing, shift work, bullying, and lack of control over how you do your job. A 2019 survey of more than 20,000 nurses found that 79 percent named stress as their top job hazard, 53 percent regularly worked through breaks to keep up, and 27 percent said their workloads were too heavy. In that same survey, 24 percent reported verbal or nonverbal aggression from supervisors and 31 percent from peers. Bullying, repeated harmful actions intended to humiliate or undermine, can cause lasting psychological and physical damage.
How Risk Is Assessed
The standard process for managing risk in a workplace follows five steps, as outlined by the UK’s Health and Safety Executive: identify hazards, assess the risks those hazards create, put controls in place, record your findings, and review those controls over time. This framework applies whether you’re running a construction site or an office.
Identifying hazards means walking through the work environment and asking what could cause harm. Assessing risk means looking at each hazard and judging how likely it is to actually hurt someone and how bad the outcome could be. A risk that is both highly likely and potentially fatal sits at the top of the priority list. A risk that is unlikely and would cause only minor discomfort sits near the bottom.
This process isn’t always done on paper ahead of time. In fast-changing environments like emergency response, workers use what’s called a dynamic risk assessment: continuously identifying hazards, evaluating risk, and adjusting actions in real time. A firefighter entering a burning building can’t pause to fill out a checklist. Instead, they weigh the risks against the benefits of the action, make a judgment call with the information available, and reassess as conditions change.
The Hierarchy of Controls
Once a risk is identified, the goal is to reduce it. OSHA’s hierarchy of controls ranks the available options from most to least effective.
- Elimination removes the hazard entirely. If work can be done at ground level, the fall risk disappears.
- Substitution replaces a dangerous material or process with a less dangerous one, like switching to a less toxic chemical.
- Engineering controls put physical barriers between workers and hazards. Machine guards, ventilation systems, guardrails, and noise enclosures all fall here.
- Administrative controls change how work is organized. This includes training, rotating workers to limit exposure time, inspection procedures, warning signs, and lockout protocols for equipment maintenance.
- Personal protective equipment (PPE) is the last line of defense: hard hats, safety glasses, respirators, hearing protection, and fall harnesses. PPE requires constant attention from the worker, which is why it’s considered the least reliable option.
The higher up the hierarchy you go, the less you depend on human behavior to keep people safe. A guardrail protects everyone automatically. A hard hat only works if someone remembers to wear it.
What “Acceptable Risk” Means
No workplace can eliminate every risk entirely. The practical question is: how low does a risk need to go? In the UK, the governing principle is ALARP, which stands for “as low as reasonably practicable.” It means you must keep reducing a risk until the cost, time, and effort of further reduction would be grossly disproportionate to the safety benefit gained.
This principle has legal weight. It originated in a 1949 court ruling (Edwards vs. National Coal Board), where the judge stated that the severity of a risk must be weighed against the sacrifice needed to avert it. If the risk is small and the cost of eliminating it is enormous, the risk may be tolerable. But there are hard limits. The UK’s Health and Safety Executive sets a maximum tolerable fatality risk of 1 in 1,000 per year for workers and 1 in 10,000 per year for members of the public. If a risk exceeds those thresholds, it must be reduced or the activity stopped, regardless of cost.
In practice, this means organizations are expected to invest in safety measures proportional to the danger. A company can’t ignore a known risk simply because fixing it is expensive, but it also isn’t expected to spend unlimited resources on a negligible threat.
International Standards for Risk Management
ISO 45001 is the international standard for occupational health and safety management systems. It provides a framework that applies to organizations of any size and requires them to systematically identify hazards, assess risks, implement controls, and continually improve. The standard follows a Plan-Do-Check-Act cycle: plan your safety objectives, implement them, monitor whether they’re working, and adjust based on what you find.
Key requirements include leadership commitment, worker participation in safety decisions, emergency planning, and incident investigation. The standard also requires organizations to stay current with applicable health and safety regulations. For workers, this translates into workplaces where safety isn’t treated as an afterthought but is built into daily operations, with regular reviews and clear channels for reporting concerns.