Chemical hazard

• Inhalation

The most common exposure route to chemicals in the work environment is through inhalation. Gas, vapor, mist, dust, fumes, and smoke are all chemicals that can be inhaled. Chemicals are inhaled when a worker breathes in contaminated air through their mouth and/or nose and then subsequently into their lungs. Those with occupations involving physical work will inhale higher levels of chemicals. This is because workers who do physical work will exchange over 10,000 liters of air over a 8-hour day, while workers who do not do physical work will exchange only 2,800 liters.[4] If the air is contaminated in the workplace, more air exchange will lead to the inhalation of higher amounts of chemicals.

• Ingestion

The ingestion of chemicals occurs when chemicals enter into the worker’s mouth and are swallowed. Ingesting chemicals commonly occurs when food and/or drink is contaminated by unwashed hands, personal protective equipment, and/or clothing.

• Contact with Skin and or Eyes

Chemical exposure to the skin is a common workplace injury. The exposure of chemicals to the skin most often results in local irritation to the exposed area. In some exposures, the chemical will be absorbed through the skin and will result in poisoning. The eyes have a strong sensitivity to chemicals, and are consequently an area of high concern for chemical exposure. Chemical exposure to the eyes results in irritation and, in many instances, burns and vision loss.

• Injection

Injection is the most uncommon method of chemical exposure in the workplace. Chemicals can be injected into the skin when a worker is punctured by a sharp object, such as a needle. Chemical exposure through injection results in the chemical entering directly into the bloodstream.

Hazard pictographs are a type of labeling system that alerts people at a glance that there are hazardous chemicals present. The symbols help identify whether the chemicals that are going to be in use may potentially cause physical harm, or harm to the environment. The symbols are distinctive, as they are shaped like diamonds with red borders. These signs can be divided into:

• Explosive (exploding bomb)
• Flammable (flame)
• Oxidizing (flame above a circle)
• Corrosive (corrosion of table and hand)
• Acute toxicity (skull and crossbones)
• Hazardous to environment (dead tree and fish)
• Health hazard/hazardous to the ozone layer (exclamation mark)
• Serious health hazard (cross on a human silhouette)
• Gas under pressure (gas cylinder)[5]

These pictographs are also subdivided into class and categories for each classification. The assignments for each chemical depends on their type and their severity.

• Elimination and Substitution

Chemical exposure is estimated to have caused approximately 190,000 illnesses and 50,000 deaths of workers annually.[6] There exists an unknown link between chemical exposure and subsequent illness and/or death. Therefore, the majority of these illnesses and deaths are thought to be caused by a lack of knowledge and/or awareness concerning the dangers of chemicals. The best method of controlling chemical exposure within the workplace is through the elimination or the substitution of all chemicals that are thought or known to cause illness and/or death.

• Engineering Controls

Although the elimination and the substitution of the harmful chemicals is the best known method for controlling chemical exposure, there are other methods that can be implemented to diminish exposure. The implementation of engineering controls is an example of another method for controlling chemical exposures. When engineer controls are implemented, there is a physical change made to the work environment that will eliminate or reduce the risk to chemical exposure. An example of engineer controls is the enclosure or isolation of the process that creates the chemical hazard.

• Administrative and Work Practices Controls

If the process that creates the chemical hazard cannot be enclosed or isolated, the next best method is the implementation of administrative and work practices controls. This is the establishment of administrate and work practices that will reduce the amount of time and how often the workers will be exposed to the chemical hazard. An example of administrative and work practices controls is the establishment of work schedules in which workers have rotating job assignments. This will ensure that all workers have limited exposure to chemical hazards.

• Personal Protective Equipment (PPE)

Employers should provide personal protective equipment (PPE) to protect their workers from chemicals used within the workplace. The use of PPE prevents workers from being exposed to chemicals through the routes of exposure—inhalation, absorption through skin and/or eyes, ingestion, and injection. One example of how PPE usage can prevent chemical exposure concerns respirators. If workers wear respirators, they will prevent the exposure of chemicals through inhalation.

In case of emergency, it is recommended to understand first aid procedures in order to minimize any damage. Different types of chemicals can cause a variety of damage. Most sources agree that it is best to rinse any contacted skin or eye with water immediately. Currently, there is insufficient evidence of how long the rinsing should be done, as the degree of impacts will vary for substances such as corrosive chemicals. However, the recommended flush time is as follows:

• 5 minutes - non- to mild irritants
• 15 minutes - moderate to severe irritants and chemicals that cause acute toxicity
• 30 minutes - most corrosives
• 60 minutes - strong alkalis such as sodium, potassium or calcium hydroxide

Transporting the affected person to a health care facility may be important, depending on condition. In the case that the victim needs to be transported before the recommended flush time, then flushing should be done during the transportation process. Some chemical manufacturers may state the specific type of cleansing agent that is recommended.[7]

• Anthropogenic hazard – Hazard caused by human action or inaction
• Biocontainment
• Biological agent – Pathogen that can be weaponized
• Biosafety level – Level of the biocontainment precautions required to isolate dangerous biological agents
• Hazard – A substance or situation which has the potential to cause harm to health, life, the environment, property, or any other value
• Health hazard
• Hierarchy of hazard controls – System used in industry to eliminate or minimize exposure to hazards
• Mechanical hazard – Hazard with a mechanical energy source
• Occupational exposure banding – Process to assign chemicals into categories corresponding to permissible exposure concentrations
• Occupational hazard – Hazard experienced in the workplace
• Physical hazard – Hazard due to a physical agent
• Planetary protection – A guiding principle in the design of an interplanetary mission, aiming to prevent biological contamination of both the target celestial body and the Earth
• Psychosocial hazard – Occupational hazard to one's psychological well-being
• Public health – Preventing disease, prolonging life and promoting health through organized efforts and informed choices of society and individuals