Introduction 

Despite new technologies in manufacturing, a variety of toxic agents remain key in the manufacture of many products and can produce serious health and environmental hazards. Heavy metals, such as lead and mercury, are vital in batteries and electronics. Volatile organic compounds like benzene and formaldehyde are vital in plastics and construction materials. However, these chemicals are critically necessary yet highly toxic. 

Similarly, metals like arsenic (semiconductors and wood preservative) and hexavalent chromium (metal finishing) are chemicals that display the length and level of contamination by toxic inputs necessitating: 

  • Health and safety measures 
  • Engineering for exposures and 
  • Rigorous waste disposal practices  

In this way, you can protect workers and the public against toxic agent exposure. Supporting worker safety from toxic agent exposures requires ongoing effort to expand safety protocols, develop innovative engineering methods for exposure, and assure government regulations and environmental compliance are met. 

10 Most Toxic Substances Commonly Used for Manufacturing 

While modern manufacturing drives innovation and productivity, it relies on a subset of substances whose extreme toxicity demands rigorous controls. Understanding the hazards, industrial applications, and safety protocols for these top 10 poisons is critical to protect workers, communities, and the environment. 

1. Benzene

Use in Manufacturing: Production of plastics, resins, synthetic fibers, rubber, dyes, detergents, and pesticides.
Hazards: Classified as a Group 1 human carcinogen by IARC. Chronic exposure damages bone marrow, causes anemia, and increases the risk of acute myeloid leukemia. Acute inhalation can cause dizziness, headaches, and unconsciousness.
Safety Measures: 

  • Closed system processing and local exhaust ventilation 
  • Continuous air monitoring with benzene detectors 
  • Mandatory use of respirators when controls are insufficient 
  • Substitution with less toxic solvents where feasible 

2. Formaldehyde

Use in Manufacturing: Intermediate for resins (urea-formaldehyde, phenol-formaldehyde), textiles, paper, and disinfectants.
Hazards: Classified as carcinogenic to humans (IARC Group 1). Acute exposure causes mucosal irritation, coughing, and asthma-like symptoms; chronic exposure linked to nasopharyngeal cancer and leukemia.
Safety Measures: 

  • Fully enclosed reaction vessels 
  • Automated reagent feeding to minimize manual handling 
  • Continuous monitoring at threshold limit value (0.1 ppm ceiling) 
  • Engineering barriers and personal protective equipment (PPE) 

3. Hydrogen Cyanide

Use in Manufacturing: Precursor to plastics (acrylonitrile), fumigants, and synthetic fibers; gold and silver extraction in precious metal refining.
Hazards: Extremely toxic from inhalation and ingestion. Inhibits cytochrome c oxidase, leading to cellular asphyxiation. Lethal concentration is about 100 ppm for a few breaths; rapid onset of convulsions, respiratory collapse, and cardiac arrest.
Safety Measures: 

  • Inert-gas blanketing of storage tanks 
  • Detectors with immediate alarm thresholds 
  • Emergency antidote kits (hydroxocobalamin) on-site 
  • Comprehensive evacuation and decontamination procedures 

4. Phosgene

Use in Manufacturing: Intermediate for polycarbonates, isocyanates (for polyurethane foams), and pesticides.
Hazards: A pulmonary irritant that reacts with proteins in the alveoli. Inhalation can lead to delayed-onset pulmonary edema, respiratory distress, and death. Historically used as a chemical warfare agent.
Safety Measures: 

  • Double-containment gas-tight systems with automatic scrubbers 
  • Real-time gas monitoring is equipped with redundant fail-safe alarms 
  • Respiratory protection with full-face supplied air respirators 
  • Detailed decontamination stations and medical surveillance 

5. Hydrofluoric Acid (HF)

Use in Manufacturing: Glass etching, metal cleaning, semiconductor etching, and production of fluorine chemicals.
Hazards: Highly corrosive; penetrates tissue deeply, causing severe chemical burns and systemic toxicity by binding calcium and magnesium ions, leading to hypocalcemia, hypomagnesemia, and potentially fatal arrhythmias. Even small skin exposures can be deadly.
Safety Measures: 

  • Use of HF-resistant gloves, face shields, and acid-resistant suits 
  • Availability of calcium gluconate gel for immediate topical treatment 
  • Strict segregation of HF processes with automated fluid handling 
  • Comprehensive training on emergency response 

 

6. Mercury

Use in Manufacturing: Previously used in chlorine and caustic soda production (mercury cell process), fluorescent lamps, chemical catalysts, and electrical switches.
Hazards: Neurotoxin causes tremors, cognitive deficits, and renal damage. Elemental mercury vapor is readily absorbed through the lungs. Chronic exposure impairs CNS and may result in acrodynia in children (“pink disease”).
Safety Measures: 

  • Phasing out mercury cell plants in favor of membrane processes 
  • Closed loop lamp recycling and vacuum sealed lamps 
  • Mercury vapor analyzers in work areas 
  • Strict mercury spill protocols with specialized cleanup teams 

 

7. Lead

Use in Manufacturing: Batteries, ammunition, cable sheathing, radiation shielding, and solder.
Hazards: Cumulative neurotoxin causes cognitive impairment, anemia, renal dysfunction, and reproductive toxicity. No safe blood lead level has been identified; occupational exposure limit is 50 µg/dL.
Safety Measures: 

  • Substitution with lead-free solders and paints 
  • HEPA filtered local exhaust in battery recycling and smelting 
  • Routine biological monitoring (blood lead) 
  • Prohibition of lead work for pregnant employees 

 

8. Arsenic

Use in Manufacturing: Wood preservatives (chromated copper arsenate), semiconductor doping, metal alloys, and glass manufacturing.
Hazards: Carcinogenic (skin, lung, bladder), causes peripheral neuropathy, hyperkeratosis, and cardiovascular disease. Chronic ingestion is linked to Blackfoot disease and skin cancer.
Safety Measures: 

  • Closed system dosing of chromate compounds 
  • Rigorous dust control in smelting and glass operations 
  • Biomonitoring of urinary arsenic species 
  • Strict wastewater treatment to remove arsenic 

 

9. Carbon Monoxide

Use in Manufacturing: Metallurgical processes (ferrous and non-ferrous), chemical production (phosgene synthesis), and fuel in heat treatment furnaces.
Hazards: Odorless, colorless gas that binds hemoglobin with 240× the affinity of oxygen, causing hypoxic injury. Symptoms include headache, dizziness, and at high concentrations, loss of consciousness and death.
Safety Measures: 

  • Continuous CO monitoring in enclosed spaces 
  • Adequate ventilation of combustion areas 
  • Use of low-carbon combustion systems and CO scrubbers 
  • Worker training on recognizing CO poisoning signs 

 

10. Asbestos

Use in Manufacturing: Historically in insulation, brake linings, cement, and textiles; still found in legacy applications.
Hazards: Inhalation of fibers leads to asbestosis, lung cancer, and mesothelioma. There is no threshold for safe exposure; risks persist decades after exposure.
Safety Measures: 

  • Complete phase-out in most countries; regulated removal in older facilities 
  • Wet methods and HEPA-filtered vacuums during abatement 
  • Respiratory protection and medical surveillance for workers in demolition or renovation 
  • Strict disposal protocols in sealed, labeled containers 

Conclusion 

Every workplace with poisons must have workers employ one or generally all of the “hierarchy of controls” to address the hazards and risk of exposure: elimination or substitution; engineering controls; administrative controls; and (PPE). Continuous training, environmental monitoring, and preparation for emergencies are a must for worker safety.