Introduction 

All workplaces working with hazardous chemicals have an obligation to safeguard workers against any risks to their health in the long run. Although various chemicals pose the danger of causing immediate harm like burns and irritants, some chemicals create another problem by posing a greater danger of causing cancer in the event of exposure. 

Workplace carcinogens, according to the relevant authorities, are responsible for causing cases of preventable illnesses in various fields, including manufacturing, construction, healthcare, laboratories, mining, farming, and chemical processing. It is vital to know the nature of the chemicals that cause cancer at workplaces, how they get exposed to workers, and ways of controlling them. This guideline seeks to inform you on various types of workplace carcinogens, their prevalence in various industries, possible health impacts, regulatory policies, and ways to minimize exposure. 

What are the chemicals that cause cancer in the workplace?

Carcinogens, workplace chemicals that lead to cancer, are those substances that have been proven to increase the possibility of developing cancer because of being exposed to them over time. Contrary to some chemicals that show instant reactions, carcinogens cause delayed reactions whereby a person can develop a disease as many as several decades after being exposed to them.

However, not all workplace chemicals are carcinogenic since there exist other chemicals that could be corrosive, toxic, flammable, or environmentally dangerous without causing cancer. There are various ways of determining whether some chemicals are carcinogenic through toxicological, epidemiological, and regulatory assessments done by the IARC, OSHA, NTP, and others. Risk is dependent on various things, such as

• Concentration of the chemical
• Exposure time
• Exposure frequency
• Mode of uptake
• Susceptibility of the person
• Control measures in place at work

A chemical labeled as a carcinogen does not necessarily mean that one gets cancer. Rather, the label means that there is an increased possibility of getting cancer when not properly controlled.

Quick facts about workplace carcinogens

Why workplace carcinogens matter 

Occupational cancer can be prevented. While accidents happen instantaneously, cancers that result from occupational exposure take years to develop, since cancer happens because of continued exposure to harmful substances over long periods. 

An individual could spend years working with the substance without experiencing any adverse symptoms, which makes it hard to identify such a hazard. Employers who cannot manage the carcinogenic chemicals will face the following: 

• Increased illness among their employees 
• Non-compliance with regulations 
• Increased costs of worker's compensation 
• Disruptions in operations 
• Liabilities 
• Damaged reputation 

Chemical management programs assist companies in minimizing such risks as well as ensuring compliance with safety regulations.

How can chemicals cause cancer?

Cancer occurs because of mutations in healthy cells that affect their normal growth and repair processes. Some chemicals used at workplaces can be implicated in causing cancer because they damage DNA, interfere with normal cellular functions, or induce cell division. In most cases, the onset of cancer among workers because of chemical exposure is determined by accumulative effects. In some cases, it can take 10 to 40 years for workers to exhibit signs of occupational cancer. A general chain of causation can be described as follows:

Exposure to Chemicals → Damage to Cells → Mutations in DNA → Growth of Abnormal Cells → Development of Cancer

Not all exposed workers will suffer from occupational cancer. Various factors will determine the vulnerability of a person.

Understanding the latency period 

The latency of the disease is another hallmark characteristic of occupational cancer. For instance, an employee who is exposed to cancer-causing chemicals now can develop occupational cancer many years later. As such, it might become challenging to trace the origin of exposure. 

Some examples of such diseases caused by occupational exposure are the following: 

• Occupational mesothelioma is caused by prolonged exposure to asbestos. 

• Occupational leukemia caused by being exposed to benzene over a long period of time. 

• Occupational lung cancer because of breathing in crystalline silica. 

Thus, one needs to take the necessary preventive steps in advance. 

How workers are exposed to carcinogenic chemicals

Understanding exposure routes is essential for selecting the right control measures.

1. Inhalation

Inhalation is the most frequent mode of exposure to occupational hazards. The workers may inhale:

• Chemical vapors
• Poisonous gases
• Particulate dust
• Aerosol
• Fumes
• Smokes

Industries engaged in operations such as grinding, cutting, spraying, heating, or chemical production create air-borne contaminants that can enter the body through inhalation.

2. Skin contact

Several dangerous substances are capable of passing through the skin or irritating the skin to increase their absorption. Exposure to skin takes place during:

• Chemical mixing
• Cleaning the apparatus
• Handling of contaminated equipment
• Maintenance operations
• Cleanup of spills

Appropriate use of chemical-resistant gloves and protective clothing reduces skin exposure.

3. Accidental ingestion

Chemicals can find their way into the body through unintentional ingestion. This happens when the worker:

• Eats at the polluted workplace
• Smokes while handling the chemicals
• Touches his/her food with polluted gloves
• Does not wash hands before eating

Maintaining good housekeeping will minimize this problem.

4. Eye exposure

Chemical splashing or even aerosolized particles can enter the eyes during laboratory procedures, chemical transfers, sprays, or maintenance activities. Although exposure to chemicals in the eyes alone is unlikely to result in cancer, it indicates improper procedure and more chemical exposure in general. Safety glasses and face shields must be chosen based on the specific dangers described in the Safety Data Sheet.

Factors that increase cancer risk in the workplace

The likelihood of developing occupational cancer depends on more than simply working around hazardous chemicals. Several workplace conditions can significantly increase exposure:

1. Poor ventilation

Inadequate airflow allows hazardous vapors, fumes, and dust to accumulate in work areas.

2. Lack of personal protective equipment

Failure to wear suitable gloves, respirators, or protective clothing increases direct chemical contact.

3. Improper chemical storage

Leaking containers, damaged packaging, and incompatible storage conditions may increase employee exposure.

4. Inadequate training

Employees who do not understand chemical hazards are more likely to handle substances incorrectly or ignore safety procedures.

5. Missing or outdated safety data sheets

Without access to current SDS information, workers may be unaware of carcinogenic classifications, recommended PPE, emergency procedures, or exposure controls.

6. Poor housekeeping

Chemical residues left on work surfaces, equipment, or floors increase the risk of repeated exposure over time.

How are carcinogenic chemicals classified? 

There are several organizations that conduct scientific evaluations to confirm that a particular chemical can induce cancer. While different classification systems may differ in some ways, all of them consider the reliability of scientific studies, not the degree of exposure to that substance at a particular workplace. Among such systems, we can highlight the following: 

• International Agency for Research on Cancer (IARC): This organization classifies different substances according to their carcinogenic properties in people and animals. 

• Occupational Safety and Health Administration (OSHA): This body regulates occupational exposure to carcinogens and safety requirements for employers. 

• National Toxicology Program (NTP): This organization prepares the Report on Carcinogens, containing information about chemicals that are known to cause cancer or those substances that might induce malignancy. 

• Globally Harmonized System (GHS): It is the internationally agreed-upon system for classifying different hazards and labelling. 

• European Chemicals Agency (ECHA): This agency classifies carcinogenic substances according to CLP regulation. 

Understanding these classifications helps employers identify high-risk substances and implement appropriate exposure controls before health effects occur. 

Common workplace chemicals associated with cancer risk 

Although many different chemicals are used in industrial settings, there are only a few that are known to be potential or likely workplace carcinogens. This chemical is present in all sorts of industrial facilities, including manufacturing plants, labs, hospitals, construction sites, oil refineries, and others. Here is a list of some of the most important workplace carcinogens and their respective industrial environments. 

1. Benzene

Benzene is one of the most extensively studied occupational carcinogens. It is a colorless, highly flammable liquid widely used in petroleum refining, chemical manufacturing, and the production of plastics, synthetic fibers, rubber, dyes, and detergents. 

Common industries 

• Oil and gas 

• Petrochemical plants 

• Chemical manufacturing 

• Printing 

• Rubber manufacturing 

• Fuel storage facilities 

Exposure routes 

• Inhalation of vapors 

• Skin absorption 

• Accidental ingestion 

Health risks 

Repeated exposure may affect the bone marrow and reduce the body's ability to produce healthy blood cells. Long-term occupational exposure has been associated with an increased risk of leukemia and other blood-related cancers. 

Risk reduction 

• Install local exhaust ventilation. 

• Conduct routine air monitoring. 

• Use chemical-resistant gloves and protective clothing. 

• Wear approved respiratory protection where necessary. 

• Store benzene in tightly sealed, labeled containers. 

2. Formaldehyde

Formaldehyde is commonly used as a preservative and industrial chemical in laboratories, healthcare facilities, textile production, furniture manufacturing, and resin production. 

Common industries 

• Hospitals 

• Pathology laboratories 

• Furniture manufacturing 

• Textile production 

• Chemical manufacturing 

Exposure routes 

• Inhalation 

• Eye contact 

• Skin contact 

Health risks 

Repeated exposure can irritate the eyes, nose, throat, and lungs. Long-term occupational exposure has been associated with certain cancers affecting the upper respiratory tract. 

Risk reduction 

• Improve workplace ventilation. 

• Keep exposure below occupational limits. 

• Wear eye protection and chemical-resistant gloves. 

• Store containers securely to minimize vapor release. 

3. Crystalline silica

Crystalline silica is generated during activities such as cutting, grinding, drilling, or crushing materials, including concrete, stone, brick, and engineered stone. 

Common industries 

• Construction 

• Mining 

• Stone fabrication 

• Glass manufacturing 

• Foundries 

Exposure routes 

• Inhalation of respirable dust 

Health risks 

Long-term exposure may lead to silicosis, chronic lung disease, and an increased risk of lung cancer. 

Risk reduction 

• Use wet cutting methods. 

• Install dust collection systems. 

• Provide properly fitted respirators. 

• Monitor airborne dust concentrations regularly. 

4. Asbestos

Although heavily regulated in many countries, asbestos remains present in older buildings, insulation materials, roofing products, and industrial equipment. 

Common industries 

• Demolition 

• Construction 

• Shipbuilding 

• Building maintenance 

• Industrial renovation 

Exposure routes 

• Inhalation of airborne fibers 

Health risks 

Occupational exposure has been associated with mesothelioma, lung cancer, and asbestosis. 

Risk reduction 

• Identify asbestos-containing materials before work begins. 

• Restrict access to contaminated areas. 

• Use certified asbestos removal procedures. 

• Wear approved respiratory protection. 

5. Hexavalent chromium (chromium VI)

Hexavalent chromium compounds are widely used for corrosion resistance and metal finishing. 

Common industries 

• Welding 

• Aerospace 

• Stainless steel manufacturing 

• Electroplating 

• Metal finishing 

Exposure routes 

• Inhalation 

• Skin contact 

Health risks 

Long-term exposure has been associated with lung cancer and may also cause severe skin irritation and respiratory disease. 

Risk reduction 

• Install local exhaust systems. 

• Use enclosed processing equipment. 

• Wear respiratory protection during welding operations. 

• Conduct periodic exposure assessments. 

6. Vinylchloride

Vinyl chloride is primarily used in the production of polyvinyl chloride (PVC), one of the world's most widely used plastics. 

Common Industries 

• Plastic manufacturing 

• Chemical production 

• Polymer processing 

Exposure routes 

• Inhalation 

Health risks 

Long-term occupational exposure has been associated with an increased risk of liver cancer and other liver disorders. 

Risk reduction 

• Use closed processing systems. 

• Continuously monitor air quality. 

• Maintain leak detection programs. 

• Provide employee training in emergency procedures. 

7. Ethyleneoxide

Ethylene oxide is widely used to sterilize heat-sensitive medical equipment and pharmaceutical products. 

Common industries 

• Hospitals 

• Medical device manufacturing 

• Pharmaceutical production 

• Sterilization facilities 

Exposure routes 

• Inhalation 

• Skin absorption 

Health risks 

Repeated exposure has been associated with increased risks of certain cancers and reproductive health effects. 

Risk reduction 

• Use automated sterilization systems. 

• Install continuous gas monitoring. 

• Improve ventilation. 

• Train employees on safe handling procedures. 

8. Diesel exhaust

Workers operating diesel-powered machinery indoors or in poorly ventilated environments may experience prolonged exposure to diesel exhaust. 

Common industries 

• Mining 

• Warehousing 

• Transportation 

• Construction 

• Agriculture 

Exposure routes 

• Inhalation 

Health risks 

Long-term exposure has been linked to an increased risk of lung cancer and chronic respiratory disease. 

Risk reduction 

• Improve building ventilation. 

• Replace older diesel engines where possible. 

• Reduce engine idling. 

• Transition to lower-emission equipment. 

9. Arsenic compounds

Arsenic compounds are used in metal smelting, electronics manufacturing, and wood preservation. 

Common industries 

• Mining 

• Metal refining 

• Semiconductor manufacturing 

• Glass production 

Exposure routes 

• Inhalation 

• Skin contact 

• Accidental ingestion 

Health risks 

Long-term exposure has been associated with cancers affecting the skin, lungs, and bladder. 

Risk reduction 

• Maintain strict hygiene procedures. 

• Provide respiratory protection. 

• Perform biological exposure monitoring where required. 

• Prevent contamination of eating areas. 

10. Cadmium

Cadmium is commonly found in batteries, metal coatings, pigments, and certain manufacturing processes. 

Common industries 

• Battery manufacturing 

• Welding 

• Metal recycling 

• Electronics production 

Exposure routes 

• Inhalation 

• Ingestion 

Health risks 

Repeated exposure has been associated with lung cancer, kidney damage, and other chronic health effects. 

Risk reduction 

• Use engineering controls to capture fumes. 

• Wear respirators during welding. 

• Maintain clean work environments. 

• Monitor employee exposure levels. 

11. Nickel compounds

Nickel compounds are widely used in stainless steel production, electroplating, and battery manufacturing. 

Common industries 

• Electroplating 

• Metal fabrication 

• Mining 

• Battery production 

Health risks

Long-term occupational exposure has been associated with cancers of the nasal cavity and lungs. 

Prevention 

• Improve ventilation. 

• Reduce airborne dust. 

• Wear protective gloves and respiratory protection. 

• Follow proper housekeeping procedures. 

12. Beryllium

Beryllium is valued for its strength and lightweight properties in aerospace and defense applications. 

Common industries 

• Aerospace 

• Electronics 

• Precision manufacturing 

Health risks 

Exposure may lead to chronic beryllium disease and has been associated with an increased risk of lung cancer. 

Prevention 

• Use enclosed machining systems. 

• Conduct regular exposure monitoring. 

• Implement medical surveillance programs. 

• Provide respiratory protection. 

Industries with the highest occupational cancer risk 

Whereas carcinogenic substances can be found in almost all sectors, there are certain sectors in which there is more chance of exposure because of their nature of work. 

1. Construction 

Workers in the construction industry have been known to face exposure to substances such as crystalline silica, asbestos, diesel exhaust, welding fumes, and preservatives in treated wood. 

2. Chemical manufacturing 

In this industry, personnel can come into contact with solvents, intermediates, acids, polymers, and specialties on a day-to-day basis. An exhaustive list of chemicals, engineering controls, and Safety Data Sheets (SDS) is an important part of managing these risks. 

3. Oil and gas 

In this sector, there is typically exposure to benzene, polycyclic aromatic hydrocarbons (PAHs), and other volatile organic compounds. Monitoring leaks and routine air sampling are important parts of reducing worker exposure. 

4. Healthcare and laboratories 

Individuals working in healthcare and labs will come into contact with formaldehyde, ethylene oxide, disinfectants, and chemicals used for diagnostics. Ventilation and the use of closed handling techniques help to minimize occupational hazards. 

5. Mining and quarrying 

Mining activities put miners at risk of coming into contact with respirable crystalline silica, diesel exhaust, arsenic, nickel, cadmium, and many more hazardous materials found in nature. 

6. Metal fabrication and welding 

The welding process produces fumes that may include hexavalent chromium, nickel compounds, cadmium, and other harmful metals. The use of a local exhaust ventilation system and proper selection of respirators is highly necessary to ensure safety for the employees. 

7. Manufacturing and industrial production 

Industrial manufacturing involves a wide variety of chemical operations using adhesives, coatings, solvents, resins, polymers, and other chemicals. Proper management of chemicals, regular inspection, employee training, and SDS programs can help achieve compliance.

How employers can reduce the risk of occupational cancer 

Occupational cancer prevention is not just about equipping employees with PPEs. An employer should have in place a comprehensive chemical safety plan incorporating hazard recognition, assessment of exposure to chemicals, engineering controls, training of employees, and regulation of compliance. The best way to do this is through implementation of the Hierarchy of Controls strategy. 

1. Elimination

The best method for safeguarding employees is to ensure the removal of all carcinogens from the work environment whenever possible. This can be done through the following actions: 

• Stop using outdated chemicals 

• Eliminate unnecessary chemical reactions 

• Buying already mixed solutions to reduce handling 

• Switch from manual to automated cleaning systems 

Once the source of the hazard is eliminated, the exposure risk is removed. 

2. Substitution

Where elimination is not feasible, substitution of cancer-causing substances by alternative substances that do the same job without posing much danger to the health of employees can be considered by the employer. Examples include: 

• Use of water-based coatings rather than solvent-based coatings whenever possible 

• Use of safer cleaning products 

• Use of low-toxicity laboratory reagents where validated alternatives are available 

Substitution should always be evaluated carefully to ensure the replacement chemical does not introduce new hazards. 

3. Engineering controls

Engineering control reduces worker exposure by separating them from harmful chemicals and not depending upon their actions. Here are some examples: 

• Local exhaust ventilation (LEV) 

• Enclosed chemical transfer systems 

• Fume hood in laboratories 

• Dust collection system 

• Automated dispensing devices 

• Negative pressure rooms 

• Closed-process manufacturing 

Engineering control is considered more effective than other controls, as it eliminates hazards at the point of generation. 

4. Administrative controls

Administrative controls target workplace practices and procedures that help reduce exposure time for employees. Such controls may comprise the following: 

• Employee rotation to reduce exposure time 

• Restricted entry into high-risk areas 

• Use of SOPs in written form 

• Regular inspection of the workplace 

• Assigning high-exposure jobs when there are not many people around 

• Chemical inventory management 

Safety training is one of the most important administrative controls that help employees become familiar with chemical hazards and proper working procedures.

5. Personal protective equipment (PPE) 

The use of PPE becomes the last resort if the hazards are not reduced fully by other methods of control. The choice of proper PPE is determined by the chemicals, route of exposure, and activities performed. The recommended PPE for common chemical handling tasks:

Personal protective equipment needs to be regularly inspected and replaced if there is any damage. PPE needs to be chosen according to the guidelines given in the SDS. 

Safe storage and handling of carcinogenic chemicals 

Safe storage will prevent accidental exposure and ensure compliance with regulations. Employers should: 

• Clearly label every chemical container.  

• Store incompatible chemicals separately.  

• Keep chemicals in approved, tightly sealed containers.  

• Maintain adequate ventilation in storage areas.  

• Protect chemicals from excessive heat, moisture, and direct sunlight.  

• Inspect containers regularly for leaks or deterioration.  

• Limit access to authorized personnel.  

• Display emergency contact information and spill response procedures.  

Proper housekeeping also prevents contamination of work surfaces and minimizes accidental exposure. 

What should you do during a chemical spill? 

Despite the measures taken to prevent spills, they may happen. It is recommended that there is always an emergency response plan for each company and that all employees know it and practice it. Spill response in general consists of the following steps: 

• Identification of the chemical which was spilled 

• Review of the Safety Data Sheet (SDS) 

• Evacuation of unnecessary personnel in case it is needed 

• Dressing up in proper protective gear 

• Prevention of the spread of the chemical in the drain or in the surrounding area 

• Application of spill control equipment 

Disposal of the materials used in accordance with local requirements. 

The role of safety data sheets (SDS) in managing carcinogenic chemicals 

One of the best ways of ensuring that employees are safe from any form of chemical hazards in the workplace is through Safety Data Sheets (SDSs). According to the Occupational Safety and Health Administration, an employer has to ensure that all employees have access to updated SDS for every hazardous chemical in the workplace. Some of the information that can be found on a safety data sheet includes: 

• Chemical identification 

• Hazard classification 

• Carcinogenicity 

• Exposure pathways 

• Occupational exposure limit 

• PPE recommendations 

• Safe handling information 

• Storage information 

• First aid measures 

• Fire-fighting information 

• Information on how to deal with spills 

• Disposal information 

Maintaining accurate and up-to-date SDSs enables employees to make informed decisions before handling hazardous substances and supports compliance during workplace inspections and audits. 

OSHA and regulatory requirements 

For any organization handling carcinogens, it is necessary to adhere to the laws concerning workplace health and chemical safety regulations. There are several standards, which can be used as guidelines for managing chemical risks. 

OSHA hazard communication standard 

According to the OSHA HazCom Standard: 

• Maintaining a list of hazardous chemicals 

• Ensuring proper labeling of all containers 

• Giving training to employees regarding chemical hazards 

• Making available the latest Safety Data Sheets 

• Writing hazard communication programs 

It is made to ensure that employees know the hazards related to the chemicals they use at their workplace. 

Globally harmonized system (GHS) 

The Globally Harmonized System (GHS) standardizes the classification and communication of chemical hazards worldwide. GHS helps employers by providing: 

• Consistent hazard classifications  

• Standardized pictograms  

• Uniform signal words  

• Harmonized hazard statements  

• Precautionary statements  

• A globally recognized SDS format  

Using GHS-compliant labels and SDSs improves hazard communication across international workplaces and supply chains. 

Exposure monitoring 

Employers need to do exposure monitoring periodically when employees are handling chemicals that may present health hazards in the long run. Exposure assessment assists organizations in: 

• Assessing the effectiveness of engineering control measures 

• Finding out hazardous areas in the workplace 

• Comparing air levels with permissible exposure levels 

• Knowing whether more protection is needed 

Monitoring is particularly essential in those industries where air-borne dust, vapors, or fumes are produced.

Employer compliance checklist 

Organizations can strengthen their chemical safety programs by implementing the following best practices: 

• The chemical inventory should always be kept updated 

• SDSs for all hazardous chemicals should be current and available 

• Proper labeling of all containers according to GHS guidelines should be ensured 

• Employee Safety Training should be conducted on a regular basis 

• Workplace Exposure Assessment is recommended 

• A proper ventilation system should be installed and maintained 

• Provision of Personal Protective Equipment and its proper use should be ensured 

• A spill response plan should be developed 

• Safety Inspections and Audits should be conducted 

References

1. Occupational Safety and Health Administration (OSHA) – Hazard Communication Standard (29 CFR 1910.1200) – Requirements for chemical hazard communication, Safety Data Sheets (SDS), labeling, and employee training.
2. Occupational Safety and Health Administration (OSHA) – Chemical Hazards and Toxic Substances – OSHA guidance on workplace exposure to hazardous chemicals and exposure limits.
3. International Agency for Research on Cancer (IARC) Monographs – Scientific evaluations of the carcinogenicity of chemicals, mixtures, and occupational exposures.
4. National Toxicology Program (NTP) – Report on Carcinogens – U.S. government list of substances known or reasonably anticipated to cause cancer.
5. National Institute for Occupational Safety and Health (NIOSH) – Pocket Guide to Chemical Hazards – Exposure limits, health hazards, PPE recommendations, and chemical safety guidance.
6. National Institute for Occupational Safety and Health (NIOSH) – Hierarchy of Controls – Best practices for eliminating or reducing workplace exposure to hazardous chemicals.

Frequently asked questions (FAQs) 

What are workplace carcinogens? 

Workplace carcinogens refer to chemicals or other substances that have been proven to elevate chances of getting cancer when exposed occupationally for prolonged periods. 

Does exposure to carcinogenic chemicals result in cancer? 

No. The development of cancer is determined by several factors, such as dosage, frequency, mode of exposure, susceptibility, and workplace controls, among others. 

In which industries are there higher exposures to carcinogenic chemicals? 

The construction, manufacturing, mining, chemical industry, health care, laboratories, oil and gas, and metalworking industries are some of those that use carcinogenic materials. 

Which is the most common route of exposure in the work environment? 

The inhalation of airborne dust, vapor, fume, and gas is the most common route of occupational exposure to many carcinogens.  

Can harmful chemicals enter through skin? 

Yes. Certain hazardous chemicals can be absorbed via the skin, making protective gloves and clothing mandatory while handling them.  

What does an SDS contain? 

An SDS contains hazard identification, carcinogenic information, personal protective equipment, first aid information, storage guidelines, spillage guidelines, firefighting information, and disposal information. 

When do employees require chemical safety training? 

It should take place when new hazardous chemicals are added, whenever process changes happen, and regularly as part of workplace safety programs.  

Is every hazardous chemical carcinogenic? 

Not all of them are carcinogenic, although they may be toxic, corrosive, flammable, or reactive substances.  

What is the importance of ventilation? 

Ventilation ensures that the concentration of hazardous substances will not exceed acceptable levels and allows for avoiding inhaling hazardous chemicals.  

How can employers minimize exposure to carcinogenic chemicals? 

They can use the Hierarchy of Controls, keep SDS documents available, provide proper PPE, improve ventilation, conduct exposure monitoring, and give safety training.