Best Non-Toxic Leave in Conditioner in 2025

Anthracene (ANT) is prominently used in various sectors including dyeing, organic semiconductor research, and the creation of smoke screens. ANT ingestion is linked to melanosis coli, a condition potentially tied to colorectal tumors, and increased apoptosis in epithelial cells. In workplace exposure studies (1946-2002), workers exposed to ANT and similar substances developed different skin cancers, however, no carcinogenicity was found in animal skin tests. Genotoxicity tests on bacteria presented negative results for most cases while ecotoxicity studies showed that ANT exposure caused oxidative stress in organisms and proved fatal for bluegill sunfish under sunlight.

Benzalkonium chloride, when used as a spermaticide, can cause vaginal irritation. A fatal dose by ingestion is 1-3 grams, with symptoms including vomiting, convulsions, and coma. It is corrosive to eyes, a skin irritant, and can cause allergic contact dermatitis, methemoglobinemia and hemolysis. It has a potential to kill within 1-3 hours if concentrated solutions are ingested. Despite the threat it poses, there are no data on its carcinogenicity or teratogenicity and it doesn't interfere with embryo development in rats.

Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon released into the atmosphere through various processes, including industrial activities, forest fires, and burning of fuel. Human exposure to BaP is associated with adverse birth outcomes, diminished fertility, neurobehavioral effects, and strong evidence of carcinogenicity in certain occupations. Accumulation of BaP in human blood plasma contributes to chromosomal aberrations. Animal studies demonstrate BaP's association with developmental, reproductive, and immunological effects, indicating its carcinogenic nature. Ecotoxicity studies on various species like ducks and rainbow trout indicate poor survival rates and developmental abnormalities, evidencing BaP's broad capacity for environmental harm.

Butylparaben, a chemical used in various products, has been shown to cause skin irritation in humans and potential sensitization in dermatitis patients. Animal studies indicate that it has low to moderate oral toxicity and can cause damage to the liver, spleen, and thymus. It can also lead to cell proliferation in rats' stomachs, though it was not found to be carcinogenic or mutagenic. However, it may negatively impact sperm viability and activity, as demonstrated in different in vitro and in vivo studies. Lastly, it proposed weaker aquatic toxicity compared to parabens with longer alkyl chains, but still showed estrogenic effects in certain fish species.

Cetrimonium Bromide is a versatile substance utilized in various products, including topical anti-bacterial and anti-fungal preparations, cosmetics, hair care, throat lozenges, antiseptic gels, and vaccine production. It serves as a surfactant and emulsifier and typically requires skin contact to cause a rash. Its applications range from skincare and haircare products to throat lozenges and vaccine production.

DEA Oleth-3 phosphate is employed in skincare as an emulsifying, cleansing, and dispersing agent that facilitates the cohesive mixing of oil and water ingredients in cosmetic products. It is a combination of ethoxylated fatty acid oleic acid and liquid phosphoric acid. However, ethanolamines like diethanolamine (DEA), found in various consumer products including cosmetics and cleaning products, have been associated with liver tumors. To reduce contamination from carcinogenic nitrosamines, the European Commission prohibits the use of DEA in cosmetics.

DEA-Cetyl Phosphate serves as an emulsifier and surfactant in cosmetics and personal care products. However, it can accumulate in the liver and kidneys, leading to organ toxicity and potential neurotoxic effects like tremors. Maternal exposure to DEA may also have lasting impacts on memory function and brain development in offspring. Furthermore, DEA has been linked to male reproductive health issues, causing abnormalities in sperm structure and function.

Ethylparaben is a chemical used as a preservative in various products including pharmaceuticals, cosmetics, and adhesives. It exhibits low toxicity in humans and animals, but can cause skin irritation, particularly when applied to damaged skin, and may worsen pre-existing skin conditions. Despite causing cell proliferation in rats' forestomachs and chromosomal aberrations in a hamster ovary cell test, it has shown no evidence of causing cancer. However, it was found to be toxic to fetuses at doses toxic to the mother, though it did not cause malformations (nonteratogenic). Interestingly, while it impacted sperm viability in lab conditions, it showed no negative effects on mouse sperm in actuality.

Isobutylparaben belongs to the paraben family of preservatives used in the food, pharmaceutical, and personal care product industries. Parabens mimic estrogen and have been found in breast cancer tumors in some studies. Parabens are commonly found in various personal care products and foods and have been associated with endocrine disruption, skin cancer risk, developmental and reproductive toxicity, and potential behavioral changes in offspring when exposed during gestation.

Isopropylparaben belongs to the parabens family of preservatives utilized in the food, pharmaceutical, and personal care sectors. Parabens have estrogen-mimicking properties and pose a potential risk as endocrine disruptors. Research has detected parabens in the breast cancer tumors of a significant number of studied women, raising concerns about their safety and hormonal effects.

Lauramide DEA is an ethanolamide mixture of lauric acid commonly used in soaps, cleansers, and shampoos. It is known to cause mild to moderate eye irritation and mild to severe skin irritation. While the Cosmetic Ingredient Review (CIR) Expert Panel has deemed it safe for use, caution is advised in cosmetics and personal care products that also contain nitrosating agents to prevent the formation of potentially carcinogenic nitrosamines.

Linoleamide MEA is utilized in cosmetics for functions such as foam boosting, antistatic properties, viscosity control, and hair conditioning. It is used in a wide range of consumer products, including cosmetics, personal care items, and household cleaning products. However, it has the potential to irritate the eyes and skin at higher concentrations and may cause short-term exposure-related effects on the central nervous system, nasal irritation, or pulmonary edema.

Methylparaben is an antimicrobial preservative used in food, drugs, and cosmetics. Some individuals can develop contact dermatitis on skin exposure, and allergic reactions have been reported on ingestion, though the evidence is not conclusive. Data from animal studies suggest that methylparaben is practically non-toxic and non-irritating in normal skin conditions, with high thresholds for observed adverse effects. However, it showed chromosome aberrations in a cell assay and variable results in different uterotrophic assays. An ecotoxicity study found changes in the expression of certain genes at specific concentrations in male medaka, a type of fish.

Methylparaben is a non-volatile compound used as an antimicrobial preservative in various products, with contact exposure reported to cause dermatitis in some people. The mechanism of this sensitivity is not well understood, but it seems to intensify when applied to broken or damaged skin. Animal studies showed it to be generally non-toxic and non-carcinogenic, with no significant adverse effects noted at high exposure levels. There were contrasting findings on its effect in uterotrophic assays and its toxicity to sperm cells. In ecotoxicity studies, it affected the expression levels of genes in male Medaka fish at certain concentrations

Octinoxate, commonly found in various cosmetic and personal care products such as hair color products, sunscreen, lipstick, and skin creams, is an endocrine disruptor that mimics estrogen and can affect thyroid function. It has been detected in human urine, blood, and breast milk, indicating systemic exposure. Octinoxate's potential health concerns include its impact on cell proliferation in response to estrogen exposure, disruptions in thyroid hormones, alterations in reproductive systems, and adverse effects on the development of male and female fetuses, as well as their offspring.

Oleamide DEA is utilized in shampoos, hair dyes, bath products, and lotions for enhancing foaming capacity, stabilizing foam, and thickening the water-based components. However, there is a concern that in cosmetics, DEA can react with other ingredients to create a carcinogen called nitrosodiethanolamine (NDEA), which can be absorbed through the skin.

2-Hydroxy-4-methoxybenzophenone (Benzophenone-3; BP-3) is a compound used as a UV absorber and stabilizer in plastics, paints, and sunscreens. Human studies have found photosensitivity to it, while non-human animal studies have found that high concentrations contribute to changes in liver weight and disruptions to reproductive parameters in mice and rats. It is identified as an endocrine-disrupting chemical and can affect the behavior of certain fish species. Despite this, it did not induce gene mutations in tests with the bacterium Salmonella typhimurium.

Ingestion or dermal absorption of the chemical at more than 800-1000 mg/kg/day can lead to central nervous system depression and liver and kidney changes in animals, despite there being no significant developmental toxicity. The chemical acts as an eye irritant; however, it is poorly absorbed through the skin. Unanticipated side effects are unlikely unless there is exposure to mists of heated liquid. Notably, animal feeding studies have shown that the chemical could damage the CNS, liver, kidneys, red blood cells, and the reproductive system.

Polyquaternium, modified polymers through quaternization are known for skin toxicity and allergenicity. Prolonged exposure, especially for hairdressers and janitors, may pose risks. It's found in various products, including hair conditioners, creams, and household cleaning items. Concerns include skin irritation, formaldehyde release, and contact dermatitis. Regulations in the EU limit Quaternium-15 to 0.2% in cosmetics, while the US lacks specific regulations.

Propylparaben is a stable, non-volatile compound utilized as an antimicrobial preservative in food, drugs, and cosmetics. Human exposure can cause sensitization especially if applied to damaged skin and may cause contact sensitivity with high concentrations. Extensive animal studies reveal that propylparaben is relatively non-toxic, yet it can mildly irritate skin, affect sperm counts in substantial levels, and trigger cell proliferation in the forestomach of rats. However, it is not carcinogenic, mutagenic, or clastogenic, and a significant no-observed-adverse-effect level was reported in rats. Ecotoxicity studies show that it can lead to an increase in plasma vitellogenin levels in rainbow trout and a significant decline of vitellogenin production in zebrafish at varying concentrations.

Resorcinol is a white crystalline compound with various uses in areas like tanning, photography, resin manufacture, adhesives, and cosmetics. It can be used medically as an antifungal, antibacterial, and keratolytic agent, and in dermatology-related treatments, specifically for acne amongst others. Direct skin contact with the compound can cause redness, itching, dermatitis, and even corrosion of the affected area. Overexposure could lead to symptoms like irritation, dermatitis, dyspnea, drowsiness, hypothermia, and changes to spleen, kidney, and liver. Animal studies have shown that high oral doses can result in fatalities whereas smaller doses can cause changes to liver weights with no reported carcinogenic effect or mutations in Salmonella typhimurium strains.

Stearamide Monoethanolamine (MEA) is an ingredient in cosmetics and personal care products like deodorants, shampoos, makeup, and bath items. Its role is to thicken the water-based part of these products and enhance their foaming properties and foam stability. MEA was found to be non-irritating to the skin at a 17% concentration, but it caused slight to moderate irritation to the eyes of rabbits.

The study on 1,576 U.S. workers exposed to TiO2 for over a year from 1956 to 1985 showed no increase in lung cancer or chronic respiratory disease, and no cases of pulmonary fibrosis. Cases of pulmonary fibrosis related to TiO2 exposure have been reported, possibly due to silica contamination. There are no listed effects for short-term or long-term exposure. Although NIOSH recognises ultrafine TiO2 as a potential occupational carcinogen, data is insufficient to classify fine TiO2 similarly. Epidemiological studies do not provide clear evidence of lung cancer risks from TiO2 dust exposure.

An eye irritant; May cause corneal damage on prolonged contact; [CAMEO] A skin and eye irritant, based on animal studies; [IUCLID] An irritant; May cause serious eye injury; [MSDSonline] See Triethanolamine.

Xylene is a colorless, flammable liquid with a sweet odor that can be found in cosmetic products. Its functions include enhancing fragrance and perfuming the skin, as well as serving as a solvent to dissolve other substances in the formulation. However, it's important to note that exposure to xylene can lead to various health issues, including irritation of the eyes, nose, skin, and throat, along with symptoms like headaches, dizziness, confusion, and loss of muscle coordination.

1,4-Dioxane is a clear, water-soluble liquid that is primarily used as a solvent in chemical manufacturing and laboratory reagents. Other uses leverage its solvent properties, including cosmetics, detergents, and shampoos. However, manufacturers generally reduce 1,4-Dioxane to low levels in these products due to its potential health risks. Acute exposure can result in symptoms such as vertigo, drowsiness, and irritation of the eyes, nose, throat, and skin. Chronic exposure may lead to liver and kidney damage, and the substance is classified as a probable human carcinogen by the EPA. Notably, severe kidney and liver damage, CNS effects, and even death have been recorded after heavy or prolonged exposure.

Benzalkonium chloride (BAC) is an organic salt known for its robust antimicrobial properties, effective against various bacteria, viruses, and fungi. It is frequently employed in healthcare settings like hospitals for disinfecting instruments and surfaces. Additionally, BAC is present in many consumer items, including hand sanitizers, wipes, eye solutions, nasal sprays, and personal care products such as soaps and shampoos. Although typically safe when used as instructed, BAC can lead to skin and eye irritation, particularly at elevated concentrations.

Benzene is a colorless, sweet-smelling, highly flammable liquid that evaporates quickly into the air and slightly dissolves in water. It's a byproduct of both natural processes and human activities, used extensively in the U.S production of other chemicals for plastics, resins, nylon, rubbers, lubricants, dyes, detergents, drugs, and pesticides. Present in crude oil, gasoline, and cigarette smoke, benzene is also released into the air from burning coal, oil, gasoline stations, and vehicle exhaust. Short-term exposure may cause drowsiness, dizziness, and irritation, while long-term exposure leads to blood disorders, reproductive effects, and even leukemia. Benzene has been classified by EPA as a known human carcinogen, and regulations apply to various industry sectors with potentially high exposure risks.

Diethanolamine is a chemical found in various consumer products like shampoos, cosmetics, and pharmaceuticals. Acute exposure in humans can result in irritation of the nose, throat, and skin. However, no detailed data is available on its chronic, reproductive, developmental or carcinogenic effects on humans. Studies on animals reveal that acute oral exposure can influence the liver, blood, kidney, and central nervous system, while dermal exposure has been connected with an increased incidence of liver and kidney tumors in mice. Production of first-degree burns, skin irritation, occupational asthma, kidney, and liver injury risk, and potential skin sensitization are some other adverse effects associated with diethanolamine.

Ethylene oxide is a flammable, sweet-smelling gas that easily dissolves in water. This man-made compound is primarily used to create ethylene glycol, which is used to make antifreeze and polyester, and is also used in small quantities for controlling insects in stored agricultural products, sterilizing medical equipment and fumigating spices. Ethylene oxide may cause irritation of the eyes, skin, nose, throat, and lungs, damage to the brain and nervous system, reproductive effects, and is considered by the EPA to be carcinogenic if inhaled. Exposure risks, which are notably prevalent for healthcare workers engaged in sterilization tasks, include CNS depression, eye and mucous membrane irritation and in some cases, cataracts. Despite these hazards, there are conflicted reports regarding ethylene oxide's carcinogenicity in humans.

Formaldehyde is a colorless, flammable gas with a pungent smell that's naturally produced in small quantities in human bodies and is also known as methanal amongst other names. It's used in the production of various items such as fertilizers, paper, plywood, and urea-formaldehyde resins as well as in some foods and household products like antiseptics, medicines, and cosmetics. Exposure to formaldehyde, which can occur through breathing contaminated indoor air, tobacco smoke, or ambient urban air can lead to respiratory symptoms, irritation of the eyes, nose and throat and has been linked to lung and nasopharyngeal cancer as well as leukemia. The EPA considers formaldehyde a probable human carcinogen (Group B1) and inhaling it can cause bronchospasm and pulmonary edema. Commercially, it's sold as formalin in solutions of 37%, 44%, or 50% and long-term exposure can cause first-degree burns, skin sensitization, squamous cell nasal cancer, and chronic pulmonary obstruction.

5-chloro-2-methyl-4-isothiazolin-3-one (CMI) is a compound frequently used as a preservative in cosmetics, hygiene products, and other industrial applications such as hydraulic fracturing fluids. It can also be deployed as a pesticide in the U.S, pending regulatory approval. CMI, which is often used in combination with 2-methyl-4-isothiazolin-3-one (MI), can cause contact dermatitis in humans. Various animal studies have shown that a high exposure to a CMIT/MIT mixture can cause alterations in rats' liver function. The production and use of CMI in a range of products mean it can be release into the environment, with some susceptibility to degradation through photolysis in sunlight. Its mobility in soil is high but volatilization from soil or water surfaces is not expected to be significant. Occupational and general exposure to CMI can occur especially through inhalation and dermal contact with CMI-containing products.

Methylisothiazolinone can reportedly cause allergic contact dermatitis in workers who interact with products containing it. This substance is recognized as a contact allergen for consumers using cosmetics that include it. It can cause skin burns and sensitization, and inhaling it may lead to corrosive injuries in the upper respiratory tract and lungs. Ingesting this substance is harmful, and inhalation is toxic. This preservative is linked to the category of isothiazolinones.

Naphthalene is a white solid, also known as white tar and tar camphor, found in substances like petroleum, coal, tobacco, and wood. It vaporizes easily and has a strong but not unpleasant odor. Major uses for naphthalene include the production of polyvinyl chloride (PVC) plastics, moth repellents, toilet deodorant blocks, and other chemicals such as dyes and resins. Acute exposure to naphthalene can trigger hemolytic anemia, liver damage, and neurological conditions, with chronic exposure potentially leading to cataracts and retina damage. The substance is considered a possible human carcinogen and high doses have lethal potential, particularly for individuals with specific health conditions.

Sodium laureth sulfate, derived from ethoxylated lauryl alcohol, is a surfactant used in sudsy products like toothpaste, detergents, and shampoos. While it acts as a cleansing and emulsifying agent, it can sometimes contain toxic impurities such as 1,4-dioxane. This chemical has raised health concerns due to its potential to cause skin, lung, and eye irritation, organ toxicity, and, primarily because of contamination by 1,4 dioxane, cancer.

Toluene is a clear, colorless liquid that naturally occurs in crude oil and the tolu tree. It's prominent in the production of gasoline, coke from coal, and various consumer products like paints, adhesives, and nail polish. Toluene is even added to gasoline, used to create benzene, and acts as a solvent. However, exposure to toluene, especially from inhalation, can have serious health effects. It primarily targets the central nervous system, inducing symptoms like fatigue, nausea, headaches, and in chronic cases, can cause severe dysfunction. Exposure has also been linked to developmental effects in children, but there isn't enough evidence to conclude its carcinogenic potential. Abuse of toluene can cause permanent brain damage, liver injury, and even potential birth defects or increased risk of spontaneous abortions in pregnant women. Despite these risks, cognitive deficits from toluene exposure below a threshold limit value (TLV) of 50 ppm remain extremely low.

Triethanolamine appears to cause occupational asthma and allergic contact dermatitis in machinists and photographers, as well as liver and kidney damage in animals with high-dose feeding. It's noted to be an irritant to the skin, eyes, and respiratory tract, with potential to cause skin sensitization, though the rate of skin sensitization in humans is low. Triethanolamine has low acute toxicity, with median oral LD50 values of 4,190-11,260 mg/kg in rats and 5,300-8,000 mg/kg in guinea pigs, and a median dermal LD50 greater than 2,000 mg/kg in rabbits. Triethanolamine is not carcinogenic, developmental toxicant, or toxic to the reproductive system. However, chronic exposure may lead to liver and kidney damage.

Quaternium-15 is a preservative commonly used in cosmetics which is known to significantly contribute to allergic contact dermatitis in users. This condition has been reported in various professions, including hairdressers, machine maintenance engineers at a chicken processing plant, and photocopy workers. Notably, Quaternium-15, as a formaldehyde releaser, increases dermatitis risk. However, rinse-off products typically pose a lower risk of resulting in allergic contact dermatitis.