Carcinogens are both intentionally and unintentionally added to a wide range of products and may be chemical, physical, or biological in nature. They are cancer-causing agents capable of disrupting normal cellular processes. Scientists have identified more than 100 substances as known carcinogens, and there are thousands more that are considered possible or probable. 

Carcinogens are among the many harmful chemicals we prohibit in Green Seal-certified products to ensure products meet a high standard for protecting people and the planet. 

Here, we’ll examine what carcinogens are, how and where they’re used, and how to reduce your exposure to this hazardous group. 

What are Carcinogens? 

Carcinogens, by definition, are substances that can cause or contribute to cancer. They do this by interfering with how cells grow and divide — damaging DNA, disrupting normal cellular controls, or promoting chronic inflammation — which can lead to uncontrolled cell growth and ultimately, cancer.  

Carcinogens are classified by leading scientific organizations based on the strength of evidence linking them to cancer in humans or animals. For example, the International Agency for Research on Cancer (IARC) and the U.S. National Toxicology Program (NTP) regularly review scientific data to determine whether a substance should be considered a known, probable, or possible human carcinogen. 

Carcinogens can occur naturally or be man-made. They are sometimes intentionally added to products for functional purposes but also appear as contaminants from raw materials or chemical reactions.  

Carcinogens in Consumer Products 

Carcinogens can find their way into everyday products both as intentionally added ingredients and as contaminants. They can be found in everything from air fresheners and cleaning supplies to cosmetics and food packaging. 

Carcinogens can leach out or break down, especially if a product is exposed to heat or heavy use. This increases the chances that we’ll breathe them in, get them on our skin, or accidentally ingest them. Sometimes residues from these chemicals can persist in the environment, contaminating water, soil, and food sources.  

Common Examples of Carcinogens  

Several widely recognized carcinogens are found in consumer products. This list of carcinogens includes: 

• Benzene  
  Benzene can be found in some adhesives, cleaning agents, paints, and paint strippers. Chronic exposure is strongly linked to blood cancers such as leukemia. 

• Asbestos  
  Once common in insulation and fireproofing materials, asbestos exposure is associated with mesothelioma and lung cancer. 

• Formaldehyde  
  Formaldehyde is sometimes used as a preservative or bonding agent in building materials and personal care items and is classified as a probable human carcinogen. 

The Risks of Carcinogens 

There’s no completely safe level of exposure to a confirmed carcinogen. But the level of risk depends on how much you’re exposed to, for how long, and how it enters your body. 

Some exposure is hard to avoid, especially from environmental sources. But we can reduce the risk by choosing safer products and advocating for stronger regulations. While many harmful substances have been banned or restricted, others are still prevalent — sometimes because safer options haven’t been found yet or because they’re still allowed in certain products. 

Despite their known risks, products do not always disclose carcinogens. To minimize your exposure to these harmful ingredients: 

• Look for reputable third-party certifications, such as Green Seal®, which evaluate and restrict carcinogenic ingredients in certified products. 

• If products are not certified, choose ones with full ingredient disclosure, avoiding those that list vague terms such as “fragrance” or “preservatives” without specifics. 

• Improve indoor air quality by increasing ventilation and avoiding products that emit volatile organic compounds (VOCs), including formaldehyde. 

• Use personal protective equipment (PPE) such as gloves and respirators to reduce the chance of inhaling or touching products with carcinogens, when alternatives are not available. 

• Stay informed about recalls and health advisories related to carcinogenic contaminants in consumer goods, food, and water.