Chemical and Biological Hazards: Protecting Human Health in the Workplace

Every day, workers across industries come into contact with substances that have the potential to cause serious, sometimes irreversible harm. From the drain cleaner used by a maintenance crew to the bloodborne pathogens encountered by a hospital nurse, chemical and biological hazards are a constant reality of the modern workplace. Understanding what these hazards are, where they occur, and how to control them is not just a regulatory requirement – it is a matter of life and health.

Types of chemical hazards in the workplace 🔗

Chemical hazards are substances that can damage human health or the surrounding environment through skin contact, inhalation, or ingestion. OSHA classifies hazardous workplace chemicals into several categories based on how they cause harm, and two of the most commonly encountered are corrosives – specifically acids and caustics (also called bases or alkalis).

Acids 🔗

An acid is a compound with a pH below 7.0. Commonly used workplace acids include hydrochloric (muriatic), sulfuric, and nitric acid, which appear in industries ranging from metalworking and battery manufacturing to fertilizer production. When acids come into contact with skin – especially in concentrated forms – they react with moisture (including sweat) and cause chemical burns. Strong acids with pH values between 1 and 3 can also release corrosive gases if they spill and mix with incompatible substances, adding an inhalation risk to the direct contact danger.

Caustic chemicals (bases/alkalis) 🔗

A caustic is a compound with a pH above 7.0. Common caustics include sodium hydroxide (lye), potassium hydroxide, and calcium hydroxide – substances found in cleaning agents, degreasers, drain cleaners, and industrial manufacturing processes. Unlike acids, caustics have a bitter rather than sour taste, but they are equally destructive to organic tissue, burning and corroding on contact. A quick identification rule: any chemical ending in “hydroxide” is a caustic.

Other chemical hazard categories 🔗

Beyond corrosives, workplaces also encounter reactive chemicals – substances that produce dangerous reactions when exposed to air, water, or other materials. A well-known example is the combination of bleach and ammonia, which releases toxic chloramine fumes. Reactive chemicals can trigger explosions, toxic gas releases, or intense heat generation, making proper storage and segregation from incompatible substances essential. Carcinogens represent another category – chemicals that can cause cancer over time with repeated or prolonged exposure, including certain solvents and industrial dyes.

Exposure to any of these substances can occur through four main routes: skin contact, inhalation, ingestion (often through contaminated hands touching food), and eye contact. Chemical splashes to the eyes are particularly serious and can cause permanent damage.

Biological hazards and the sectors most at risk 🔗

A biological hazard, or biohazard, is any substance produced by a living organism that can threaten human health. Sources of biological hazards include bacteria, viruses, insects, plants, birds, animals, and humans, and the resulting health effects can range from skin irritation and allergic reactions to serious infections such as tuberculosis or HIV. Unlike chemical hazards, biological hazards are often invisible to the naked eye, which makes them particularly insidious.

Healthcare workers 🔗

Healthcare settings carry some of the highest biological hazard risk. Workers are regularly exposed to blood, body fluids, and airborne pathogens. Nosocomial infections – those acquired from hospital environments – can expose workers to organisms like methicillin-resistant Staphylococcus aureus (MRSA), which is resistant to many common antibiotics. Bloodborne pathogens including HIV, Hepatitis B, and Hepatitis C are a persistent risk, particularly from improper management of sharps such as needles. The CDC identifies several unsafe practices that increase risk, including improper disinfection of equipment, reuse of syringes, and poor hand hygiene.

Environmental and sanitation services 🔗

Workers in sanitation, waste management, and environmental cleaning regularly handle sewage, contaminated materials, and biohazardous waste. Employees in these roles face risks from bacteria, viruses, and harmful fungi present in organic waste and contaminated surfaces. Environmental services workers in healthcare settings face a double exposure risk: both biological pathogens from patient environments and the chemical hazards of the disinfectants used to control them. OSHA recommends using EPA-registered disinfectants along with appropriate PPE for cleaning environments contaminated with blood or other potentially infectious materials.

Agriculture and laboratory workers 🔗

Agricultural workers face exposure to zoonotic diseases (infections transmitted from animals to humans), stinging insects, organic dust, and fungal spores. Laboratory workers handling research samples deal with biological agents at various biosafety levels. A systematic review of occupational biological hazards covering 79 studies found that while prevention measures in healthcare and laboratory settings are relatively well-defined, agriculture and waste sectors lag significantly behind – highlighting a critical gap in worker protection.

Safety measures for mitigating exposure risks 🔗

Controlling chemical and biological hazards requires a layered approach. No single measure is sufficient on its own. The most effective strategies combine engineering controls, administrative protocols, and personal protective equipment (PPE).

Know the hazard: Safety Data Sheets and labeling 🔗

OSHA’s Hazard Communication Standard (HCS) requires all employers with hazardous chemicals to provide Safety Data Sheets (SDS) and proper labels for every hazardous substance in the workplace, and to train workers on how to use them. The SDS is the first point of reference in any chemical exposure scenario – it specifies the nature of the hazard, safe handling procedures, and emergency response steps. For biological hazards, Biosafety Level (BSL) designations serve a similar purpose, specifying the containment requirements for different classes of biological agents.

Personal protective equipment (PPE) 🔗

OSHA standard 29 CFR 1910.132 requires employers to assess workplaces for hazards and provide appropriate PPE when other controls cannot reduce exposure to safe levels. For chemical hazards, this typically means chemical-resistant gloves (nitrile or neoprene for acids and caustics), chemical splash goggles, face shields, and protective clothing. For biological hazards in healthcare, it includes gloves, gowns, masks, and eye protection. PPE training must cover not just when to use equipment, but how to correctly put it on, remove it, and dispose of it – improper doffing is a common source of contamination.

It is important to note that PPE reduces the likelihood of exposure but does not eliminate the hazard – it is a secondary control measure, not the primary one. Engineering controls (like ventilation systems and biosafety cabinets) and administrative controls (like safe work procedures and restricting access) should always come first.

Emergency preparedness and response 🔗

Accidental releases of chemicals and biological agents require immediate, well-practiced responses. For chemical spills, acids and bases must always be stored separately, and spill kits with appropriate neutralizing agents should be readily available. Emergency eyewash stations and safety showers must be accessible wherever corrosive chemicals are handled. For biological incidents, the ILO recommends that workplaces establish, periodically update, and maintain emergency preparedness arrangements that account for the specific location, size, and nature of the workplace.

Training and a culture of safety 🔗

Regulation alone does not make a workplace safe – behavior does. Regular training on hazard identification, proper handling, and emergency procedures is essential. Control measures include not just engineering safeguards but management controls such as safe operating procedures, training, and supervision. Workers who understand what they are handling – and why the precautions matter – are far more likely to follow through consistently. Vaccinations, where available, add an additional layer of protection against specific biological hazards such as Hepatitis B.

What do you think? Are the safety training programs in your field robust enough to keep pace with the range of chemical and biological hazards workers actually encounter? And given that agriculture and waste management sectors lag significantly behind healthcare in biological hazard prevention, what systemic changes would make the biggest difference for workers in those industries?

References

1. https://www.osha.gov/chemical-hazards
2. https://b2b.mechanix.com/blog-categories/education/blog-chemical-hazards-acids-and-caustics.html
3. https://oshatrainingschool.com/blog/workplace-chemical-hazards-safety-tips-and-risks
4. https://www.ccohs.ca/oshanswers/biol_hazards
5. https://www.osha.gov/etools/hospitals/hospital-wide-hazards/biological-hazards
6. https://www.jointcommission.org/en-us/knowledge-library/workforce-safety-and-well-being-resource-center/worker-safety/biological-hazards
7. https://safetylineloneworker.com/blog/workplace-hazards-series-biological-hazards
8. https://www.osha.gov/coronavirus/control-prevention/environmental-services
9. https://www.sciencedirect.com/science/article/pii/S2093791123000665
10. https://www.cdc.gov/niosh/ppe/about/index.html
11. https://pmc.ncbi.nlm.nih.gov/articles/PMC12310650/
12. https://www.cdc.gov/safe-labs/php/echo-biosafety-2023/ppe-use.html
13. https://www.actenviro.com/corrosive-chemicals/
14. https://www.ituc-csi.org/IMG/pdf/biohazards_briefing_en_v2.pdf
15. https://pmc.ncbi.nlm.nih.gov/articles/PMC4147232/