C

C8 Alcohol

Use in Moderation

A fatty alcohol used as a solvent, emollient, or texture-enhancing ingredient in personal care and household products. Fatty alcohols are different from drying alcohols and are generally considered lower concern, though some individuals with sensitive skin may experience irritation depending on the formulation. 

• Commonly Found In: Beauty, Household

• Pregnancy & Breastfeeding: Generally considered safe in topical products, but use with caution if skin sensitivity occurs.

• Source: Synthetic

• EWG Rating: N/A

C10–16 Pareth

Avoid

A synthetic surfactant used to help remove grease, oils, and residue from surfaces and cleaning products. Because it is produced by ethoxylation, contamination with 1,4-dioxane (a carcinogen) may occur depending on manufacturing and purification practices. 

• Commonly Found In: Household (dish soaps, surface cleaners)

• Pregnancy & Breastfeeding: avoid due to contamination concerns

• Source: Synthetic (petroleum-derived)

• EWG Rating: 1

C12–14 Alcohols Ethoxylated Propoxylated

Avoid

A synthetically produced surfactant created through ethoxylation and propoxylation. This process can introduce contamination with 1,4-dioxane, a known carcinogen.

• Commonly Found In: Household (dish detergents, floor cleaners)

• Pregnancy & Breastfeeding: Avoid due to contamination concerns.

•  Source: Synthetic (ethoxylated, petroleum-derived)

•  EWG Rating: 2-3

C12–15 Pareth-3

Avoid

A synthetic surfactant used to improve cleansing and help water mix with oils. It is manufactured through ethoxylation, a process that may result in contamination with 1,4-dioxane (a known carcinogen) if not properly purified. While the ingredient itself is not the primary concern, many individuals choose to avoid ethoxylated ingredients due to potential contamination risks. 

• Commonly Found In: Beauty (shampoos, body washes)

• Pregnancy & Breastfeeding: Avoid due to concerns about ethylene oxide contamination.

• Source: Synthetic

• EWG Rating: 1-2

C15–19 Alkane

Use in Moderation

A synthetic emollient/solvent often used to improve spread and disperse mineral UV filters such as titanium dioxide. It can be plant-derived or petroleum-derived depending on the supplier, and it’s still chemically processed. Look for plant-derived in the ingredients.

• Commonly Found In: Beauty (sunscreens, tinted mineral sunscreens, mineral foundations, primers)

• Pregnancy: Generally considered low concern in topical use, look for plant derived ingredients

• Source: Synthetic (can be plant-derived or petroleum-derived)

• EWG Rating: 1-3

C9–11 Pareth-8

Avoid

An ethoxylated (PEG-type) surfactant used to break up grease and help formulas rinse clean. It can be irritating, particularly to the eyes and sensitive skin. Because it is manufactured via ethoxylation, contamination with 1,4-dioxane and ethylene oxide may occur if manufacturing and purification processes are not carefully controlled. Some formulations may also raise environmental concerns due to aquatic toxicity. 

• Commonly Found In: Household (dish soaps, degreasers, surface cleaners, laundry products)

• Pregnancy & Breastfeeding: Limited pregnancy-specific data; avoid due to irritants and ethoxylated-ingredient contamination concerns

• Source: Synthetic (ethoxylated; typically petroleum-derived)

• EWG Rating: 1-2

Cadmium

Avoid

A heavy metal that can build up in the body over time (especially in the kidneys) and is classified as a human carcinogen. Long-term exposure is the biggest concern.

• Commonly Found In: Household (contaminated dust, some older pigments/paint, certain imported items, some contaminated soil brought indoors, electronics)

• Pregnancy & Breastfeeding: Avoid due to carcinogenic and developmental risks

• Source: Natural (hazardous heavy metal)

• EWG Rating: N/A

Calcium Alginate

Use in Moderation

A thickener and stabilizer extracted from brown seaweed. Because seaweed can accumulate contaminants depending on growing conditions, sourcing and testing matter.

• Commonly Found In: Food + Beverage (gels, bakery glazes, restructured foods, some dairy alternatives, thickened beverages)

• Pregnancy & Breastfeeding: Generally considered low concern when properly sourced

• Source: Natural (from seaweed; processed into a food additive)

• EWG Rating: 1

Calcium Aluminum Borosilicate

Use in Moderation

A synthetic glass-based pigment used to create shimmer, sparkle, and slip in makeup. Safety concerns are generally low with normal use, but data are limited compared with more common base ingredients, and loose powders can irritate the eyes or be inhaled.

• Commonly Found In: Beauty (eyeshadow, highlighters, shimmer blush, glittery lip products)

• Pregnancy & Breastfeeding: Generally considered low concern in typical topical use; use caution with loose powders to reduce inhalation exposure

• Source: Synthetic

• EWG Rating: 2

Calcium Lactate

Use in Moderation

A processed calcium salt made from lactic acid and used to stabilize, thicken, or improve the texture of foods and beauty products. It is generally considered lower concern, but EWG flags it as a penetration enhancer, meaning it may affect the skin barrier in ways that could influence how other ingredients are absorbed. This makes the rest of the formula important, especially when it is used alongside ingredients you may not want greater exposure to. Very high intake from supplements or heavily fortified foods may also contribute to digestive upset or elevated calcium levels in some people.

• Commonly Found In: Food + Beverage (dairy alternatives, fortified drinks, canned vegetables, some baked goods, processed fruit/vegetable products)

• Pregnancy & Breastfeeding: Generally considered safe when consumed in typical food amounts

• Source: Processed (manufactured calcium salt; often made from fermentation-derived lactic acid)

• EWG Rating: 2-5 

Calcium Phosphate

Use in Moderation

A calcium and phosphorus mineral salt used as a bulking agent, anti-caking agent, firming agent, and source of calcium in foods. While generally considered low concern, frequent consumption of phosphate additives may contribute to excessive phosphorus intake. High phosphorus intake can disrupt the body's mineral balance and may affect bone, kidney, and cardiovascular health over time, particularly when consumed as part of a highly processed diet. 

• Commonly Found In: Food + Beverage (powdered drink mixes, baking mixes, processed cheese products, fortified foods, canned/processed foods, some dairy alternatives)

• Pregnancy & Breastfeeding: Foods containing phosphate additives are often highly processed and may offer fewer nutrients than whole-food alternatives. Choosing more nutrient-dense foods during pregnancy can help support healthy mineral balance and fetal development. 

• Source: Processed (mineral-derived)

• EWG Rating: 1

Calcium Sodium Borosilicate

Use in Moderation

A synthetic borosilicate glass ingredient used to add shimmer, sparkle, slip, and texture to cosmetic products. It is generally considered to be of low concern when applied to the skin, though ingredient-specific human research is limited. The primary concern is inhalation exposure to loose powders, in which fine particles may irritate the eyes or respiratory tract. 

• Commonly Found In: Beauty (eyeshadows, highlighters, shimmer blush, glittery powders, some nail products)

• Pregnancy & Breastfeeding: Generally considered low concern in typical topical use; use caution with loose powders to reduce inhalation exposure

• Source: Synthetic (borosilicate glass)

• EWG Rating: 2

Calcium Stearate

Use in Moderation

A processed ingredient made from calcium and stearic acid and used to prevent clumping and improve texture. It is generally considered lower concern, but sourcing and purity can vary. The stearic acid may come from plant or animal fats, and manufacturing specifications may allow small amounts of impurities, including heavy metals such as lead. These are expected to be present only in trace amounts when proper purity standards are followed. Powdered Calcium Stearate may also irritate the eyes or lungs if inhaled.

• Commonly Found In: Food + Beverage + Supplements (powdered spices and seasonings, drink mixes, baking mixes, capsules, tablets)

• Pregnancy & Breastfeeding: Generally considered lower concern in typical amounts. Product quality and purity matter, particularly for supplements used regularly

• Source: Processed (fatty-acid derived; plant- or animal-based)

• EWG Rating: 1

Calcium Sulfate

Use in Moderation

A naturally occurring mineral, also known as gypsum, used to improve texture, prevent clumping, and add calcium to foods and other products. It is generally considered to be of lower concern when eaten in typical amounts. The bigger concern is inhalation of powdered forms, which can irritate the nose, throat, lungs, and eyes. This makes the product's form and how you are exposed to it more important than the ingredient itself.

• Commonly Found In: Food + Beverage (baked goods, tofu, canned/processed foods, some dairy alternatives, powdered mixes)

• Pregnancy & Breastfeeding: Generally considered lower concern in typical food amounts. Avoid unnecessary inhalation of powdered forms.

• Source: Natural (mineral-derived from gypsum; purified/processed)

• EWG Rating: 1

Camphor

Avoid

A naturally derived compound used for its cooling sensation, fragrance, and temporary pain-relieving effects in topical products. While commonly used in chest rubs, muscle creams, and ointments, camphor can be toxic if ingested and may affect the nervous system at higher levels of exposure. Children are particularly vulnerable to camphor toxicity. 

• Commonly Found In: Household + Beauty (muscle rubs, chest balms, ointments, pain-relief creams, fragranced products)

• Pregnancy: Avoid due to toxicity and neurodevelopmental risk at higher exposures

• Source: Natural (wood-derived or nature-identical)

• EWG Rating: 3-4

Canola Oil (Low-Erucic Acid Rapeseed Oil)

Avoid

A highly processed vegetable oil made from specially bred low-erucic-acid rapeseed. Most conventional canola is grown from genetically modified varieties, and the oil is typically refined using multiple processing steps, including solvent extraction, high-heat processing, deodorizing, and bleaching. Canola oil also contains polyunsaturated fats that can oxidize when repeatedly exposed to high heat, light, and oxygen, creating breakdown products such as aldehydes. Organic or expeller-pressed canola oil avoids some of these concerns, but conventional highly refined canola oil does not meet a stricter low-tox, minimally processed standard.

• Commonly Found In: Food + Beverage (processed snacks, packaged baked goods, restaurant cooking oils, salad dressings, margarines)

• Pregnancy: avoid to minimize ultra-processed and solvent-refined oils, and contaminants

• Source: Plant-derived (often GMO; refined unless organic/expeller-pressed)

• EWG Rating: 1

Caramel Color

Avoid

A coloring ingredient made by heating sugars and processing them to create a brown color used in foods and beverages. Certain manufacturing methods may produce 4-methylimidazole (4-MEI), a byproduct that has raised concerns regarding carcinogenicity. Caramel color is used primarily to enhance or standardize appearance and does not provide any nutritional benefit. 

• Commonly Found In: Food + Beverage (soda, root beer, flavored coffee creamers, barbecue sauce, soy sauce, breakfast cereals, granola bars, sports drinks, candy, some plant-based milks)

• Pregnancy & Breastfeeding: Avoid due to contamination concerns

• Source: Synthetic

• EWG Rating: 1

Carbamide Peroxide

Avoid

A whitening ingredient made from hydrogen peroxide and urea that helps remove stains from the teeth. It is commonly used in whitening strips, gels, pens, and trays. While generally considered safe when used as directed, it may cause tooth sensitivity, gum irritation, mouth irritation, or digestive upset if swallowed. 

• Commonly Found In: Beauty (teeth-whitening strips, whitening gels, whitening pens, whitening trays)

• Pregnancy & Breastfeeding: Use with caution; avoid unnecessary whitening and avoid ingestion

• Source: Synthetic

• EWG Rating: 2

Carmine (Cochineal)

Use in Moderation

A natural red dye made from cochineal insects. While generally well tolerated, it can trigger allergic reactions in sensitive individuals.

• Commonly Found In: Food + Beverage + Beauty + Pharmaceuticals + Textiles (yogurt, candies, fruit snacks, juices, lipstick, blush, capsules/tablets)

• Pregnancy & Breastfeeding: Generally considered safe in typical amounts, but avoid if sensitive or for ethical reasons

• Source: Natural

• EWG Rating: 1

Carnauba Wax

Use in Moderation

A plant-derived wax from the leaves of the Brazilian carnauba palm used to add shine, create a coating, and improve texture. It is generally considered lower concern, but allergic skin reactions have been reported, including a case linked to carnauba wax in lip balm. It is also commonly used as a coating on foods and supplements, so it can be another added ingredient you may be exposed to without realizing it.

• Commonly Found In: Food + Beverage + Beauty (candy coatings, chewing gum, fruit/produce coatings, supplements, mascara, lip products)

• Pregnancy & Breastfeeding: Use in moderation, but is generally considered safe in typical use

• Source: Natural (plant-derived; finished products may include other additives)

• EWG Rating: 1

Carob Bean (Locust Bean Gum)

Use in Moderation

A natural gum made from carob tree seeds and used to thicken and improve the texture of foods. It is generally considered lower concern, but larger amounts may cause bloating, gas, diarrhea, or other digestive discomfort because it is fermented by gut bacteria. Rare allergic reactions have also been reported. Purity matters, especially in products for children, because specifications for locust bean gum include limits on toxic elements such as lead, mercury, and arsenic, and the gum can also be vulnerable to microbial or mold contamination if it is not properly processed and tested.

• Commonly Found In: Food + Beverage (ice cream, dairy alternatives, yogurt, sauces, gluten-free baking, protein drinks)

• Pregnancy & Breastfeeding: Generally considered safe, but purity matters

• Source: Natural

• EWG Rating: 1

Carrageenan

Avoid

A thickener and stabilizer made from red seaweed and commonly added to processed foods to make them thicker and creamier. Carrageenan is poorly absorbed by the body, but the bigger concern is what it may do inside the gut. Research suggests it may irritate the intestinal lining, alter gut bacteria, and trigger or worsen inflammation, especially in people with sensitive or inflamed digestive systems. Animal studies have also found GI inflammation and immune effects at higher exposures. The research is still debated, but because carrageenan provides no nutritional benefit and alternatives are widely available, it does not meet a stricter low-tox standard.

• Commonly Found In: Food + Beverage + Supplements + Beauty (dairy alternatives, deli meats, coffee creamers, protein shakes, gummies, toothpaste, lotions)

• Pregnancy & Breastfeeding: Use with caution; often avoided by those minimizing gut irritants

• Source: Natural (from seaweed

• EWG Rating: 1

Cellulase

Use in Moderation

An enzyme that breaks down cellulose and is commonly made through fermentation using fungi or bacteria. Cellulase is generally considered lower concern when eaten, but inhaling powdered forms can trigger respiratory allergies or asthma-like reactions, especially with repeated exposure. Some cellulase is made using fungal strains such as Aspergillus or Trichoderma, including genetically modified strains. The production organism is removed during manufacturing, although small amounts of proteins from the fermentation process may remain, making sourcing and purification worth considering for sensitive individuals.

• Commonly Found In: Food + Beverage (processed foods, baked goods, juices, fermented products)

• Pregnancy & Breastfeeding: No specific reproductive or developmental concerns have been identified. Use caution with powdered forms that could be inhaled.

• Source: Can be natural (bacterial- or mold-derived through fermentation)

• EWG Rating: N/A

Cellulose Gum

Use in Moderation

A thickener and stabilizer made by chemically modifying plant cellulose, usually from wood pulp or cotton. It is generally considered lower concern, but research suggests it may affect the gut microbiome and intestinal environment. In a small human study, higher daily intake changed gut bacteria, reduced microbial diversity, altered beneficial gut metabolites, and caused slightly more abdominal discomfort. Animal studies have also raised concerns around gut inflammation.

• Commonly Found In: Food + Beverage (ice cream, dairy alternatives, sauces, dressings, gluten-free baked goods)

• Pregnancy: Generally considered safe in typical food amounts

• Source: Plant-derived (processed cellulose)

• EWG Rating: 1

Ceresin

Avoid

AA mineral-based hydrocarbon wax used to thicken products, add structure, and sometimes replace beeswax. Ceresin itself is considered lower concern, but how it is sourced and refined is the bigger issue. Mineral and petroleum-derived waxes can contain PAHs (polycyclic aromatic hydrocarbons) if they are not properly refined, and some PAHs are known or suspected carcinogens. EWG requires ceresin used in EWG VERIFIED products to be highly refined, made from noncarcinogenic source material, and meet strict limits for PAH contamination. Ceresin also has concerns around persistence and buildup in the body.

• Commonly Found In: Beauty (lip balms, creams, ointments, makeup, hair products)

• Pregnancy & Breastfeeding: Avoid when possible to reduce unnecessary exposure to mineral-derived hydrocarbons and potential contaminants such as PAHs. Properly refined ceresin itself is not considered a known reproductive or developmental toxin.

• Source: Mineral-derived (petroleum/coal)

• EWG Rating: 1

Cetalkonium

Avoid

A synthetic quaternary ammonium compound, or quat, used to kill germs, preserve products, and help ingredients mix together. It can irritate the skin and eyes, and inhalation is a bigger concern because Cetalkonium Chloride has been identified as an asthma-triggering sensitizer. There are also growing reproductive and developmental concerns around quats as a group, although these effects have not been clearly established for Cetalkonium Chloride itself. It is also very toxic to aquatic life and can have long-lasting environmental effects.

• Commonly Found In: Household + Industrial (disinfectants, specialty cleaners, some industrial or professional-use formulations)

• Pregnancy & Breastfeeding: Avoid when possible, especially in sprays or products that can be inhaled. Reproductive concerns have been found with some quats in animal studies, although there is limited pregnancy-specific research on Cetalkonium Chloride itself.

• Source: Synthetic

• EWG Rating: N/A

Ceteareth-25

Avoid

A synthetic ingredient used to help oil and water mix together and improve the texture of beauty products. Ceteareth-25 is made through ethoxylation, which can leave behind ethylene oxide and 1,4-dioxane if the ingredient is not properly purified. Both are concerning manufacturing contaminants because of their links to cancer. EWG also flags Ceteareth-25 as a penetration enhancer, meaning it may help other ingredients penetrate the skin more easily. The amount of contamination depends on how well the ingredient is manufactured, purified, and tested.

• Commonly Found In: Beauty + Household (creams, lotions, sunscreens, hair conditioners, cleansers, some cleaning products)

• Pregnancy & Breastfeeding: Avoid when possible to reduce unnecessary exposure to ethoxylated ingredients and potential manufacturing contaminants such as ethylene oxide and 1,4-dioxane.

• Source: Synthetic (ethoxylated)

• EWG Rating: 1

Cetrimonium Chloride

Avoid

A quaternary ammonium compound used as a conditioning and antistatic agent in hair and personal care products. It is associated with skin and eye irritation, and inhalation exposure can be a concern in spray products.

• Commonly Found In: Beauty (conditioners, detanglers, leave-in sprays, styling creams, hair masks)

• Pregnancy: Often avoided due to irritation and inhalation exposure concerns

• Source: Synthetic

• EWG Rating: 2

Chlorhexidine Diacetate

Avoid

A synthetic antiseptic/disinfectant used to reduce bacteria. It can cause mild skin irritation and sensitivity, and allergic reactions have been reported in some individuals. This is also very toxic to aquatic life. 

• Commonly Found In: Household + Medical/Dental (antiseptic washes, mouth rinses, skin cleansers, wound care products, disinfecting solutions)

• Pregnancy: Use with caution if sensitive

• Source: Synthetic

• EWG Rating: N/A

Chlorhexidine Digluconate

Avoid

A synthetic antiseptic used to reduce bacteria in personal care and medical products. It known to cause skin irritation and allergic reactions. There are also concerns with microbial resistance and environmental impact.

• Commonly Found In: Beauty + Personal Care (acne or antibacterial washes, mouth rinses, some cleansers), Medical/Dental products

• Pregnancy: Avoid if you have sensitive skin

• Source: Synthetic

• EWG Rating: 1

Chlorine

Avoid

This poisonous disinfectant and bleaching agent is used in household cleaning and water treatment, as well as manufacturing PVC. Exposure can irritate the skin, eyes, and respiratory tract, especially in poorly ventilated areas or at higher concentrations.

• Commonly Found In: Household (bleach cleaners, disinfecting products, pool chemicals, chlorinated water exposure)

• Pregnancy: Avoid due to irritation and toxic inhalation exposure concerns

• Source: Synthetic

• EWG Rating: N/A

Chlorine Dioxide

Avoid

A synthetic oxidizing gas used as a bleaching agent in some paper processing and as a disinfectant in certain water treatment applications. Exposure can irritate the eyes, skin, and respiratory tract, especially if inhaled. Inhaling too much can cause bronchitis and asthma- like symptoms. 

• Commonly Found In: Household (some disinfecting products, water treatment applications, “chlorine-free” paper processing context)

• Pregnancy: Limited pregnancy-specific data; use with caution to minimize inhalation exposure

• Source: Synthetic

• EWG Rating: N/A

Chloroform

Avoid

A chemical that can form as a by-product of water disinfection when chlorine reacts with organic matter. Higher exposures can affect the nervous system, liver, and kidneys.

• Commonly Found In: Household (chlorinated tap water, hot showers/steam exposure, pools, some water disinfection contexts)

• Pregnancy: Avoid or minimize exposure due to organ toxicity concerns

• Source: Synthetic (disinfection by-product)

• EWG Rating: N/A

Chloromethane (Methyl Chloride)

Avoid

A volatile synthetic gas used primarily as an industrial chemical. High exposure can affect the nervous system and cause symptoms such as headache, dizziness, and nausea.

• Commonly Found In: Household (rare in typical household products; more associated with industrial use and chemical manufacturing)

• Pregnancy: Avoid due to neurotoxicity risk with inhalation exposure

• Source: Synthetic

• EWG Rating: N/A

Chlorphenesin

Avoid

A synthetic preservative used to limit microbial growth in personal care products. It can irritate the skin and may be problematic for individuals with sensitivities. In vitro research has shown cellular toxicity in ocular cells, raising concern for products used near the eye.

• Commonly Found In: Beauty (lotions, creams, serums, makeup, deodorants, hair products)

• Pregnancy: Limited pregnancy-specific data; often avoided out of caution

• Source: Synthetic

• EWG Rating: 4

Chromium Oxide Green

Avoid

A mineral-based green pigment used in cosmetics. Concerns relate to possible contamination with trace heavy metals (such as lead, cadmium, or other chromium impurities) depending on sourcing and manufacturing, as well as hazard-based assessments that flag potential developmental and reproductive toxicity.

• Commonly Found In: Beauty (eyeshadow, eyeliner, brow products, face paint, makeup pigments)

• Pregnancy: Avoid due to heavy metal contamination concerns

• Source: Mineral-derived (inorganic pigment

•  EWG Rating: 8-10

Chromium-6 (Hexavalent Chromium)

Avoid

A highly toxic form of chromium known to be carcinogenic. Exposure is associated with increased cancer risk and can damage cells and tissues.

• Commonly Found In: Household (contaminated drinking water, pollution-related exposure, some industrial residues)

• Pregnancy: Avoid due to carcinogenic and toxic exposure concerns

• Source: Naturally occurring and industrially produced

• EWG Rating: N/A

CI 42090 (Blue Lake No. 4)

Avoid

A synthetic blue colorant used in cosmetics (an aluminum “lake” form of Blue 1). EWG flags high concern for contamination, which can include trace contaminants such as heavy metals (for example lead, arsenic, cadmium, or mercury) depending on manufacturing controls, along with use restrictions and developmental/reproductive toxicity concerns.

• Commonly Found In: Beauty (makeup, skincare, hair products)

• Pregnancy: Often avoided to minimize exposure to synthetic dyes and potential trace contaminants

• Source: Synthetic

• EWG Rating: 3-8

CI 77007 (Ultramarines)

Use in Moderation

A mineral-derived inorganic pigment used to provide blue or violet color in cosmetics. While generally considered lower concern than synthetic dyes, it may contain trace heavy metals such as lead or chromium depending on raw material sourcing and purification standards.

• Commonly Found In: Beauty (eyeshadow, eyeliner, mascara, face powders)

• Pregnancy: Generally considered low concern when cosmetic-grade and impurity-controlled

• Source: Natural (mineral-derived)

• EWG Rating: 2

Citral

Use in Moderation

A naturally occurring compound found in essential oils. It may cause skin sensitivity when isolated.

Commonly Found In: Beauty, Household Pregnancy: Use with caution if skin sensitivity occurs. Source: Natural (from essential oils) EWG Rating:

Citric Acid (Synthetic)

Use in Moderation

A naturally occurring (Aspergillus niger) aromatic compound found in certain essential oils and used for fragrance. When isolated or used at higher concentrations, it is a known skin sensitizer and may cause irritation in sensitive individuals.

• Commonly Found In: Beauty + Household (fragranced skincare, personal care products, cleaning products, essential oil blends)

• Pregnancy: Use with caution, especially if you have a mold sensitivity.

• Source: Natural (from essential oils)

• EWG Rating: 1-2

Citrus Limon (Lemon) Peel Oil

Use in Moderation

A citrus-derived essential oil used for fragrance. It is a known potential skin sensitizer and may trigger allergic reactions in sensitive individuals. Irritation of the skin, eyes, or lungs is also a concern, especially in inhalable product forms like sprays.

• Commonly Found In: Beauty (cleansers, serums, creams, hair products, essential oil blends)

• Pregnancy: Use with caution due to skin sensitivity and phototoxicity concerns

• Source: Natural

• EWG Rating: 4-6

Cocamide DEA

Avoid

A surfactant made from coconut fatty acids and diethanolamine (DEA), used to create foam and thicken products. It is associated with carcinogenic risk due to DEA-related concerns and potential formation of nitrosamines.

• Commonly Found In: Beauty (shampoos, body washes, cleansers, bubble baths)

• Pregnancy: Avoid due to DEA/nitrosamine-related concerns

• Source: Synthetic

• EWG Rating: 8

Cocamide MEA

Avoid

A foaming and thickening surfactant made from coconut fatty acids and monoethanolamine (MEA). It can irritate the skin and eyes, and hazard-based assessments flag developmental and reproductive toxicity concerns.

• Commonly Found In: Beauty (shampoos, body washes, facial cleansers, liquid hand soaps, shaving creams)

• Pregnancy: Avoid due to developmental/reproductive toxicity concerns in hazard-based assessments

• Source: Synthetic

• EWG Rating: 4

Cocamidopropyl Betaine

Use in Moderation

A synthetic surfactant used to create foam and improve cleansing. It can cause skin irritation or allergic reactions in some individuals, and sensitivity is often linked to residual manufacturing byproducts such as DMAPA (3-dimethylaminopropylamine) and amidoamine.

• Commonly Found In: Beauty + Household (shampoos, body washes, facial cleansers, baby wash, liquid hand soap, household cleaners)

• Pregnancy: Use with caution if skin sensitivity occurs

• Source: Synthetic (often made from coconut-derived fatty acids)

• EWG Rating: 1-5

Cocamidopropyl Hydroxysultaine

Use in Moderation

A synthetic surfactant used to boost foam and cleansing. It may irritate the eyes in sensitive individuals. Some concerns relate to residual manufacturing byproducts such as DMAPA (3-dimethylaminopropylamine), nitrosamines, or cocamidopropyl dimethylamine, which can contribute to irritation or reactions depending on purification and quality controls.

Note: Unlike Cocamide DEA, which contains diethanolamine (DEA) as part of its chemical structure, nitrosamine concerns for this ingredient relate to possible trace manufacturing byproducts rather than the ingredient itself.

• Commonly Found In: Beauty + Household (shampoo, body wash, facial cleansers, liquid hand soap, cleaning products)

• Pregnancy: Generally considered low concern; use with caution if sensitive

• Source: Synthetic

• EWG Rating: 1

Colloidal Silver

Use in Moderation

A suspension of tiny silver particles used for antimicrobial purposes. Oral use is not supported by strong evidence for health claims and can lead to silver buildup in the body, including argyria (blue-gray skin discoloration).

• Commonly Found In: Supplements (oral drops/sprays), Oral Care (some toothpastes/mouthwashes), Beauty (some serums/creams and soaps)

• Pregnancy: Avoid unless directed by a healthcare provider

• Source: Mineral-derived (silver)

• EWG Rating: 1

Colophonium

Avoid

A tree-sap resin (also called rosin) known to trigger allergic skin reactions in sensitive individuals, especially with repeated exposure.

• Commonly Found In: Beauty (mascara, eyeliners, lip products, adhesives, hair removal waxes)

• Pregnancy: Avoid due to allergen potential.

• Source: Natural

• EWG Rating: 2

Commiphora Myrrha Gum Oil

Use in Moderation

An oil derived from myrrh tree resin that may cause skin sensitivity in some individuals depending on concentration and formulation.

• Commonly Found In: Beauty (facial oils, serums, balms, perfumes, oral care products)

• Pregnancy: Use with caution due to limited safety data and uterine-stimulating concerns with oral use.

• Source: Natural

• EWG Rating: 1

Copaiba Balsam Oil

Use in Moderation

A resin-derived oil (copaiba) that can be a skin sensitizer/allergen for some individuals, especially depending on concentration and formulation.

• Commonly Found In: Beauty (serums, facial oils, balms, essential oil blends)

• Pregnancy: Use with caution if you are sensitive

• Source: Natural

• EWG Rating: 4

Corn Maltodextrin

Avoid

A processed corn-derived carbohydrate used as a thickener or filler that can raise blood sugar quickly, especially when consumed often or in larger amounts.

• Commonly Found In: Food + Beverage (protein powders, packaged snacks, sauces, flavored drink mixes)

• Pregnancy: Avoid due to blood sugar impact.

• Source: Natural (processed from corn, often GMO)

• EWG Rating: 1

Corn Oil

Avoid

A refined oil from corn that is high in omega-6 fatty acids; frequent intake may contribute to inflammatory imbalance when overall dietary fats aren’t well balanced.

• Commonly Found In: Food + Beverage (fried foods, dressings, processed snacks, restaurant cooking oils)

• Pregnancy: Avoid due to inflammatory concerns.

• Source: Natural (refined, often GMO)

• EWG Rating: 1

Corn Starch

Use in Moderation

A refined corn starch used as a thickener and filler; it can be a fast-digesting carbohydrate depending on the food and portion size. Often GMO, Look for NonGMO.

• Commonly Found In: Food + Beverage, Supplements (soups, sauces, baking mixes, capsules/powders)

• Pregnancy: Generally considered safe in moderation.

• Source: Natural (processed from corn, often GMO)

• EWG Rating: 1

Corn Syrup

Avoid

A highly processed sweetener derived from corn starch that can raise blood sugar quickly, especially when consumed frequently or in larger amounts. Often contains GMO.

• Commonly Found In: Food + Beverage (sodas, candy, baked goods, syrups, packaged snacks)

• Pregnancy: Avoid due to blood sugar impact and GMO’s.

• Source: Natural (processed from corn, often GMO)

• EWG Rating: 1

Coumarin

Use in Moderation

A naturally occurring fragrance compound (also produced synthetically) that can act as a skin sensitizer or allergen in some individuals.

• Commonly Found In: Beauty (fragrance, perfumes, lotions, essential oil blends)

• Pregnancy: Avoid due to sensitization risk.

• Source: Natural + Synthetic

• EWG Rating: 4

Cultured Celery Powder

Avoid

A processed celery-derived ingredient used as a natural nitrite source in cured foods; nitrites can contribute to nitrosamine formation under certain conditions.

• Commonly Found In: Food + Beverage (processed meats, bacon, deli meats, sausages labeled “uncured”)

• Pregnancy: Avoid due to nitrosamine formation concerns.

• Source: Natural (cultured/fermented celery)

• EWG Rating: N/A

Cyclomethicone

Avoid

A synthetic silicone made from a mixture of cyclic siloxanes, commonly D4, D5 and D6. It is used to give skincare, makeup and hair products a smooth, silky feel and help them spread easily. The concern is that some of the cyclic silicones that can make up cyclomethicone have reproductive toxicity and environmental persistence concerns. D4, in particular, has been classified for reproductive toxicity in the EU.

• Commonly Found In: Beauty (primers, foundations, hair serums, deodorants, skincare & hair products)

• Pregnancy & Breastfeeding: Consider avoiding cyclomethicone because it can contain D4, which has reproductive toxicity concerns. This concern does not mean cyclomethicone itself has been shown to cause reproductive harm from typical cosmetic use.

• Source: Synthetic, silicone-based

• EWG Rating: 6

Cyclopentasiloxane (D5)

Avoid

A synthetic silicone used to make skincare, makeup and hair products feel silky and spread easily. D5 is persistent in the environment, and EWG flags concerns for bioaccumulation and contamination. It can also contain traces of D4, another cyclic silicone that is classified as toxic to reproduction in the EU. Inhalation is an added concern when D5 is used in sprays and aerosols.

• Commonly Found In: Beauty (primers, foundations, hair serums, deodorants, skincare & spray products)

• Pregnancy & Breastfeeding: Consider avoiding, especially in sprays and aerosols. D5 itself has not been shown to cause reproductive toxicity in available animal studies, but it may contain traces of D4, which has reproductive toxicity concerns.

• Source: Synthetic, silicone-based

• EWG Rating: 6

Cyfluthrin

Avoid

A synthetic pyrethroid insecticide used to kill insects in and around the home. Cyfluthrin works by disrupting the nervous system and can cause tingling or burning of the skin, headaches, nausea and other neurological effects with higher exposures. Inhalation is an important concern, especially when using sprays or indoor pest treatments.

• Commonly Found In: Household & Outdoor Products (insecticides, bug sprays, lawn treatments & pest control products)

• Pregnancy & Breastfeeding: Best to avoid unnecessary exposure, especially inhalation. Animal studies have found developmental effects with some exposure conditions, but this does not establish that typical household exposure causes developmental harm in humans.

• Source: Synthetic

• EWG Rating: N/A