Chemical hazard

A chemical hazard is a type of occupational hazard caused by exposure to chemicals in the workplace. Exposure to chemicals in the workplace can cause acute or long-term detrimental health effects. There are many types of hazardous chemicals, including neurotoxins, immune agents, dermatologic agents, carcinogens, reproductive toxins, systemic toxins, asthmagens, pneumoconiotic agents, and sensitizers.[1] These hazards can cause physical and/or health risks. Depending on chemical, the hazards involved may be varied, thus it is important to know and apply the PPE especially during the lab.[2]

A chemical burn

Long-term exposure to chemicals such as silica dust, engine exhausts, tobacco smoke, and lead (among others) have been shown to increase risk of heart disease, stroke, and high blood pressure.[3]

Types of hazards

• Liquids such as acids, solvents especially if they do not have a label
• Vapors and fumes
• Flammable materials[4]

Chemicals can change their physical state depending on temperature or pressure. Thus it is important to identify the health risks as these states can determine the potential route the chemical will take. For example, gas state chemicals will be inhaled or liquid state chemicals can be absorbed by the skin.[5]

Illustration of the types of chemical hazards

Routes to exposure

[6]

• Inhalation
• Absorption through skin or eyes
• Ingestion, and
• Injection

Symbols

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)[7]

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

First aid

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.[8]

Long-term risks

Cancer

Cardiovascular disease

A 2017 SBU report found evidence that workplace exposure to silica dust, engine exhaust or welding fumes is associated with heart disease.[3] Associations also exist for exposure to arsenic, benzopyrenes, lead, dynamite, carbon disulphide, carbon monoxide, metalworking fluids and occupational exposure to tobacco smoke.[3] Working with the electrolytic production of aluminium, or the production of paper when the sulphate pulping process is used, is associated with heart disease.[3] An association was also found between heart disease and exposure to compounds which are no longer permitted in certain work environments, such as phenoxy acids containing TCDD (dioxin) or asbestos.[3]

Workplace exposure to silica dust or asbestos is also associated with pulmonary heart disease. There is evidence that workplace exposure to lead, carbon disulphide, or phenoxyacids containing TCDD, as well as working in an environment where aluminium is being electrolytically produced, are associated with stroke.[3]

See also

• 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 – An agent which has the potential to cause harm to a vulnerable target
• 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

References

1. "CDC - Chemical Safety - NIOSH Workplace Safety and Health Topic". www.cdc.gov. Retrieved 2015-09-03.
2. "Chapter 8 - Chemical Hazards". sp.ehs.cornell.edu. Retrieved 2016-02-02.
3. "Occupational health and safety – chemical exposure". www.sbu.se. Swedish Agency for Health Technology Assessment and Assessment of Social Services (SBU). Archived from the original on 2017-06-06. Retrieved 2017-06-01.
4. "Safety Hazards" (PDF). OSHA.
5. "Home". www.takeonestep.org. Retrieved 2016-02-10.
6. https://www.ccohs.ca/oshanswers/chemicals/how_chem.html
7. "Hazard symbols and hazard pictograms - Chemical classification". hse.gov.uk. Health and Safety Executive. Retrieved 2016-02-11.
8. Safety, Government of Canada, Canadian Centre for Occupational Health and. "First Aid for Chemical Exposures : OSH Answers". www.ccohs.ca. Retrieved 2016-03-17.