Carbomers are synthetic ingredients that many companies use in products due to their suspending, emulsifying, and thickening properties.

Carbomer is the trade name for polyacrylic acid. Companies use it extensively in formulations across multiple industries, including cosmetics, pharmaceuticals, and personal care.

Carbomers are synthetic, crosslinked polymers of acrylic acid with a high molecular weight. Dried carbomers are lightweight, white powders. However, people frequently use them as gels or liquids.

A person may find them in a vast array of products, including:

  • shampoos
  • lotions
  • nail polishes
  • cuticle removers
  • face masks
  • styling gel
  • sunscreen
  • lipstick
  • acne treatment gels
  • moisturizers
  • detergent
  • floor cleaners
  • surface cleaning liquids
  • paints
  • waterproof and oil-proof coatings
  • printing inks

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Manufacturers across industries use carbomers extensively because of their versatility.

Companies primarily use carbomers to:

  • Thicken formulations: Many manufacturers use carbomers as thickening agents to make formulations more viscous. This helps control the consistency, texture, and flow of solutions that contain ingredients with different solubility levels.
  • Improve texture: Carbomers can also absorb and retain water, swelling up to 1,000 times their original size. This may help improve the appearance of formulations, giving them a clear, gel-like consistency. This property is responsible for providing some gels, creams, and lotions with their smooth, silky texture.
  • Stabilize formulations: Carbomers help suspend and distribute insoluble solids — which cannot dissolve — into liquid. They also prevent the oil and liquid parts of a formulation from separating. This property helps stabilize products, so they achieve a longer shelf life.

The pharmaceutical industry also uses carbomers in various ways:

  • as a bioavailability enhancer, controlling the release of drugs so the body can easily absorb them
  • as a bioadhesive to make the formulations stick to the skin and mucous membranes
  • to create a wide range of viscosity and flow in gels
  • to permanently suspend certain ingredients in oral suspensions and topical medications

People may find carbomers in products for body parts, including the eyes, mouth, intestines, nose, vagina, and rectum. Pharmaceutical companies may use carbomers in products such as tablets, transdermal patches, and creams.

The Food and Drug Administration (FDA) has approved many carbomers for use as inactive ingredients in drug products.

Furthermore, the Environmental Working Group (EWG) considers carbomer safe for use in cosmetics and personal care.

The Cosmetic Ingredient Review (CIR) Expert Panel also stated that carbomers are safe to use for cosmetics according to their present use and concentration.

An assessment by the CIR Expert Panel also noted that carbomers have a low potential risk of photo contact allergenicity and phototoxicity.

A study on rabbits demonstrated that carbomers also have a low potential risk of sensitization and skin irritation, even at high carbomer concentrations up to 100%. The CIR Expert Panel also found that carbomers had a mildly irritating effect on rabbit eyes.

A study on humans found that the potential risk of sensitization and skin irritation was low with a 1% carbomer concentration.

However, the CIR Expert Panel also noted that benzene is an impurity in carbomers. It recommended that manufacturers should reduce its concentration to the lowest possible value.

The FDA also recommends that drug manufacturers avoid using benzene during the manufacturing process. Manufacturers must report any cases of benzene contamination to the agency.

Benzene is a known toxic agent that can cause leukemia. It is also toxic to blood cells and may lead to blood disorders. Exposure to benzene may also cause bone marrow failure, which can increase a person’s risk of developing:

Learn more about potential risk factors for AML.

Environmental exposure to benzene can also cause cancers.

While traditional carbomers were usually combined to form large polymer chains (polymerization) using benzene, many modern carbomers are synthesized with processes that do not utilize benzene.

According to the EWG, carbomers are nontoxic and do not bioaccumulate in the environment.

However, some organizations, including the European Chemicals Agency, include carbomers in their lists of microplastics. Other environmental organizations refer to them as liquid microplastics. Microplastics can cause harm to the environment, wildlife, and human health. Many environment agencies define them as pieces of plastic under 5 millimeters long.

On the other hand, many manufacturers continue to use carbomers and argue that technically they are not microplastics.

The Ethical Consumer Research Association states that carbomers are liquid polymers that do not biodegrade easily.

With this in mind, further conclusive research into the long-term environmental impacts of carbomers and other liquid polymers may be necessary.

To discover more evidence-based information and resources for the environment and sustainability, visit our dedicated hub.

A person should always follow the manufacturer’s instructions when they use a product containing carbomers.

The name carbomer may have links to numbers, such as 934, 940, 941, 971, and 934P, on labels of personal care products. These numbers indicate the carbomer’s molecular weight and specific components. It can appear with other names on product labels, such as:

  • Carboxyvinylpolymer
  • Carbopol 910
  • Carbopol 971 P
  • Carbopol 981
  • Carbopol ULTREZ 20
  • Pemulen TR-1
  • Pemulen TR-2

It is also important to note that a person may be allergic to carbomers. Before using products containing carbomers, people should perform a patch test to determine if they have any allergies or sensitivities.

Carbomers are a series of polymers that derive from acrylic acid. Companies use them in a range of products as emulsifiers, thickeners, suspenders, and binders.

Research suggests that they are generally nonirritating on the skin.

Health experts generally consider carbomers safe and nontoxic for humans. However, some organizations express concerns about their environmental impact.