Risk assessment from a financial point of view.
A proposed level crossing at railroad tracks would result in "the worse death trap in Los Angeles", a California traffic engineer warned in 1915, because of the impaired view of the railway by automobile drivers. A viaduct was built instead.
Firefighters are exposed to risks of fire and building collapse during their work
Firefighters are exposed to risks of fire and building collapse during their work
Food risk assessment nomogram
Harbor sign warning visitors that use of the walkway is "at your own risk"
Ukrainian "danger" road sign. Stop for dangers, including traffic accidents, natural disasters or other road obstructions

A hazard analysis is used as the first step in a process used to assess risk.

- Hazard analysis

The probability of that harm being realized in a specific incident, combined with the magnitude of potential harm, make up its risk, a term often used synonymously in colloquial speech.

- Hazard

A hazard is a potential condition and exists or not (probability is 1 or 0).

- Hazard analysis

1) identifying and analyzing potential (future) events that may negatively impact individuals, assets, and/or the environment (i.e. hazard analysis); and

- Risk assessment

Identification of hazards assumes that the potential targets are defined, and is the first step in performing a risk assessment.

- Hazard

The validation, more precise prediction (verification) and acceptance of risk is determined in the Risk assessment (analysis).

- Hazard analysis

Risk assessment consists of an objective evaluation of risk in which assumptions and uncertainties are clearly considered and presented.

- Risk assessment

“Source of harm”. The earliest use of the word “risk” was as a synonym for the much older word “hazard”, meaning a potential source of harm. This definition comes from Blount’s “Glossographia” (1661) and was the main definition in the OED 1st (1914) and 2nd (1989) editions. Modern equivalents refer to “unwanted events” or “something bad that might happen”.

- Risk

In the context of public health, risk assessment is the process of characterizing the nature and likelihood of a harmful effect to individuals or populations from certain human activities.

- Risk

An occupational risk assessment is an evaluation of how much potential danger a hazard can have to a person in a workplace environment.

- Risk assessment

500 related topics


Reliability engineering

Sub-discipline of systems engineering that emphasizes the ability of equipment to function without failure.

A fault tree diagram
A reliability block diagram showing a "1oo3" (1 out of 3) redundant designed subsystem

Reliability engineering deals with the prediction, prevention and management of high levels of "lifetime" engineering uncertainty and risks of failure.

Many engineering techniques are used in reliability risk assessments, such as reliability block diagrams, hazard analysis, failure mode and effects analysis (FMEA), fault tree analysis (FTA), Reliability Centered Maintenance, (probabilistic) load and material stress and wear calculations, (probabilistic) fatigue and creep analysis, human error analysis, manufacturing defect analysis, reliability testing, etc. It is crucial that these analyses are done properly and with much attention to detail to be effective.

Risk management

Example of risk assessment: A NASA model showing areas at high risk from impact for the International Space Station

Risk management is the identification, evaluation, and prioritization of risks (defined in ISO 31000 as the effect of uncertainty on objectives) followed by coordinated and economical application of resources to minimize, monitor, and control the probability or impact of unfortunate events or to maximize the realization of opportunities.

According to ISO/IEC 27001, the stage immediately after completion of the risk assessment phase consists of preparing a Risk Treatment Plan, which should document the decisions about how each of the identified risks should be handled.

Typical risk analysis and evaluation techniques adopted by the medical device industry include hazard analysis, fault tree analysis (FTA), failure mode and effects analysis (FMEA), hazard and operability study (HAZOP), and risk traceability analysis for ensuring risk controls are implemented and effective (i.e. tracking risks identified to product requirements, design specifications, verification and validation results etc.).

Hazard and operability study

Firefighters are exposed to risks of fire and building collapse during their work

A hazard and operability study (HAZOP) is a structured and systematic examination of a complex planned or operation in order to identify and evaluate problems that may represent risks to personnel or equipment.

The HAZOP technique is qualitative, and aims to stimulate the imagination of participants to identify potential hazards and operability problems.

The method was further refined within the company, under the name operability studies, and became the third stage of its hazard analysis procedure (the first two being done at the conceptual and specification stages) when the first detailed design was produced.

Event tree analysis

Forward, top-down, logical modeling technique for both success and failure that explores responses through a single initiating event and lays a path for assessing probabilities of the outcomes and overall system analysis.

Event tree diagram example

3) Identify the initiating events: Use a hazard analysis to define initiating events.

7) Identify the outcome risk: Calculate the overall probability of the event paths and determine the risk.

Occupational risk assessment

A proposed level crossing at railroad tracks would result in "the worse death trap in Los Angeles", a California traffic engineer warned in 1915, because of the impaired view of the railway by automobile drivers. A viaduct was built instead.

An occupational risk assessment is an evaluation of how much potential danger a hazard can have to a person in a workplace environment.

Risks in a workplace can lead to extremely negative consequences.

The first step to an occupational risk assessment is the identification of a hazard, which is a circumstance, a cause or an action that has the capability to harm whether through injury or illness.

These take in to account other risk assessment approaches, any inadequacies, or assumptions made.

Occupational safety and health

Multidisciplinary field concerned with the safety, health, and welfare of people at work (i.e. in an occupation).

This painting depicts a woman examining her work on a lathe at a factory in Britain during World War II. Her eyes are not protected. Today, such practice would not be permitted in most industrialized countries that adhere to occupational health and safety standards for workers. In many countries, however, such standards are still either weak or nonexistent.
Harry McShane, age 16, 1908. Pulled into machinery in a factory in Cincinnati and had his arm ripped off at the shoulder and his leg broken without any compensation.
Various health and safety warning campaigns have sought to reduce workplace hazards, such as this one about ladder safety.
Workplace safety notices at the entrance of a Chinese construction site
Construction workers not wearing fall protection equipment
Rollover protection bar on a Fordson tractor
Beekeepers often wear protective clothing, for OHS reasons.
Number of occupational fatal work injuries in the U.S. from 1992 until 2014. Note, 2001 statistics do not include death related to the September 11 terrorist attacks.
The rate of fatal work injuries per 100,000 full-time equivalent workers by employee status, 2006–17. Rate = (Fatal work injuries/Total hours worked by all workers) x 200,000,000 where 200,000,000 = base for 100,000 full-time equivalent workers (FTEs) working 40 hours per week, 50 weeks per year. The total hours worked are annual average estimates from the Current Population Survey (CPS).
Source: official data FSSS, document Socio-economic indicators of the RF 1991-2016 / Социально-экономические показатели РФ в 1991-2016 on FSSS site
Hardware stores in China specializing in safety equipment
Occupational Safety Equipment
A nanomaterial containment hood, an example of an engineering control used to protect workers handling them on a regular basis.

A hazard is something that can cause harm if not controlled.

A risk is a combination of the probability that a particular outcome will occur and the severity of the harm involved.

Modern occupational safety and health legislation usually demands that a risk assessment be carried out prior to making an intervention.

Natural hazard

Natural phenomenon that might have a negative effect on humans and other animals, or the environment.

San Francisco was devastated by an earthquake in 1906
Puʻu ʻŌʻō
Young steer after a blizzard, March 1966
Hurricane Katrina

An example of the distinction between a natural hazard and a disaster is that an earthquake is the hazard which caused the 1906 San Francisco earthquake disaster.

Effective hazard analysis in any given area (e.g., for the purposes of disaster risk reduction) should ideally include an examination of all relevant hazards and their interactions.

To be of most use for risk reduction, hazard analysis should be extended to risk assessment wherein the vulnerability of the built environment to each of the hazards is taken into account.


State of being "safe", the condition of being protected from harm or other danger.

Warning signs, such as this one, can improve safety awareness.
"After Whiskey Driving Risky." Safety roadsign in Ladakh, India
Platform screen doors are primarily used for passenger safety
Safety tea cup

Eliminating all risk, if even possible, would be extremely difficult and very expensive.

Environmental hazard

Substance, state or event which has the potential to threaten the surrounding natural environment or adversely affect people's health, including pollution and natural disasters such as storms and earthquakes.

The international pictogram for environmental hazard

Environmental hazard identification is the first step in environmental risk assessment, which is the process of assessing the likelihood, or risk, of adverse effects resulting from a given environmental stressor.


Situation that poses an immediate risk to health, life, property, or environment.

An emergency medical technician treats a woman who has collapsed in the street in New York. Dangers to life and health are serious enough that emergency response systems are considered vital.
Emergency slides are deployed after the crash landing of British Airways Flight 38
A graphic representation of the four phases in emergency management.

The key principle taught in almost all systems is that the rescuer, whether a lay person or a professional, should assess the situation for danger.

A typical assessment for danger would involve observation of the surroundings, starting with the cause of the accident (e.g. a falling object) and expanding outwards to include any situational hazards (e.g. fast moving traffic) and history or secondary information given by witnesses, bystanders or the emergency services (e.g. an attacker still waiting nearby).