Best Non-Toxic Bathtub Cleaner in 2025


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Welpr Approved cleaning products are always free from:
- Harsh disinfectants and irritants: bleach, ammonia, sulfates, and quats
- Endocrine disruptors and preservatives: phthalates, parabens, BHA/BHT, triclosan
- Unnecessary additives: optical brighteners, artificial dyes, and synthetic fragrance (unless certified safe)
- Undisclosed or hidden ingredients
Common Harmful Chemicals in Bathtub Cleaner
Chemical Name
Why it’s harmful
Ammonium hydroxide is a corrosive substance that can cause injury to the skin, eyes, and respiratory tract. High concentrations, either through inhalation or prolonged exposure, can lead to significant respiratory issues, including inflammation, pneumonia, and pulmonary edema. It is used in various industries such as fertilizers, dyes, explosives, plastics, and cleansing agents, among others. Due to its intense pungency and potential to cause extreme irritation and even life-threatening conditions, precautions such as wearing protective clothing and immediate cleansing of affected areas are recommended. It should be stored away from combustibles and heavy metals, in well-ventilated areas and in specified containers. Disposal guidelines also need to be referred from environmental regulatory agencies due to the hazardous nature of the substance.
The Facts About Ammonia, Chemical Safety Facts: Ammonia, ATSDR Chemical Profile, EPA: Ammonia, Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater, EPA Chemical Profile, Mass Casualties from Acute Inhalation of Chloramine Gas, Ventilatory disorders associated with occupational inhalation exposure to ammonia, Ecological and toxicological effects of inorganic nitrogen pollution in aquatic ecosystems: A global assessment, TOXICOLOGICAL PROFILE FOR AMMONIA ,
Hydrochloric acid is used in multiple industries like chlorides, fertilizers, dyes, electroplating, and others. It has dangerous health effects like irritation and inflammation of eyes, nose and respiratory tract, and pulmonary edema after short-term inhalation; corrosion to mucous membranes, esophagus, and stomach and severe burns after oral exposure; dermatitis, photosensitization, gastritis and chronic bronchitis after long-term occupational exposure. While the EPA hasn't classified hydrochloric acid for carcinogenicity, many chemicals can spill to release HCl in water.
Sodium Dichloroisocyanurate is toxic upon ingestion and act as a strong oxidizer, posing a fire hazard when exposed to organic materials. It may react violently with combustible substances and decompose due to heat or water, releasing toxic gases such as chlorine. It can cause irritation to the skin, eyes and respiratory tract, and prolonged exposure can result in corrosive skin burns. Inhalation of high concentrations can lead to acute pulmonary edema. It may also explode from shock, friction, or other ignition sources, and can cause fires upon contact with combustible materials.
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.
Safety assessment of triethanolamine and triethanolamine-containing ingredients as used in cosmetics, Toxicology of mono-, di-, and triethanolamine, Campaign for Safe Cosmetics: Ethanolamine Compounds (MEA, DEA, TEA And Others), The Dirty Dozen: DEA-related ingredients, Chemical Profile, Special Chem, Safety assessment of triethanolamine and triethanolamine-containing ingredients as used in cosmetics
Monoalkyl phenols are primarily para substituted technical mixtures that have isomeric branched-alkyl radicals as side chains. This compound is corrosive to skin and can cause first-degree burns with short-term exposure. High inhalation can result in respiratory tract irritation, potentially leading to corrosive injuries to the upper respiratory tract and lungs. Moreover, it is harmful upon ingestion.
Diethylene glycol ethers is a chemical that has been found to have hematologic, liver, and kidney effects. Exposure to large amounts, about 250 mg/kg/day, can lead to central nervous system depression and other organ damage in rats and may decrease red blood cell counts. It does not show genotoxic, mutagenic, liver, kidney, blood, or reproductive toxicity in animals or humans, but it is classified as an exceptional allergen. The material can be absorbed through the skin and is identified as a mild skin irritant and a severe eye irritant. Notably, its toxicity is lower than that of ethylene glycol ethers.
Denatonium Benzoate causes somnolence, tremor, and ataxia in rabbits and rats according to oral lethal-dose studies and is harmful by ingestion. It is one of the most bitterly known substances, with a 1980 case report linking it to urticaria and asthma. The European Union classifies it as highly toxic by inhalation and a potential cause of serious eye injury. Lastly, it is a strong eye irritant and skin irritant according to the Sigma-Aldrich Material Safety Data Sheet.
Diethylene glycol ethers is a chemical that has been found to have hematologic, liver, and kidney effects. Exposure to large amounts, about 250 mg/kg/day, can lead to central nervous system depression and other organ damage in rats and may decrease red blood cell counts. It does not show genotoxic, mutagenic, liver, kidney, blood, or reproductive toxicity in animals or humans, but it is classified as an exceptional allergen. The material can be absorbed through the skin and is identified as a mild skin irritant and a severe eye irritant. Notably, its toxicity is lower than that of ethylene glycol ethers.
Butylphenyl methylpropional, also known as lilial, is a chemical compound commonly used in cosmetics and laundry powders. It is found naturally in crow-dipper and tomato plants and is also produced synthetically in large quantities. In May 2019, the EU's Scientific Committee on Consumer Safety (SCCS) deemed its use in cosmetics as unsafe. Following animal studies indicating reproductive toxicity, the EU banned its use in cosmetics by March 2022. Moreover, butylphenyl methylpropional can sometimes serve as an allergen, potentially leading to contact dermatitis in susceptible individuals.
Fragranced consumer products: exposures and effects from emissions, 10 reasons to avoid synthetic fragrances in cleaning products, Synthetic chemical in consumer products linked to early death, study finds, Review of the Styrene Assessment in the National Toxicology Program 12th Report on Carcinogens, Expert Panel Confirms that Fragrance Ingredient Can Cause Cancer, Fragrances, Beyond the Label: Health Impacts of Harmful Ingredients in Cleaning Products
Glycolic Acid is corrosive to the skin and eyes, with 70% technical solutions causing severe burns. It also irritates the respiratory tract and may lead to kidney failures. The chemical can cause burns when inhaled, leading to possible injuries to the upper respiratory tract and lungs. It is also harmful if ingested.
Laureth-7, a surfactant derived from lauryl alcohol sourced from coconut or palm oil, is commonly used in personal care and household products, especially laundry detergents. In detergents, it functions by reducing surface tension between water and soil, aiding in the removal of dirt, stains, and oils from fabrics. This ingredient belongs to the Polyethylene Glycols (PEGs) family, which is found in various consumer goods. Despite past contamination concerns, modern manufacturing processes have addressed and eliminated these issues. Although PEGs are not used in certain personal care products, their inclusion in machine detergents is deemed acceptable since they don't directly touch the skin.
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.
Antimicrobial agents, triclosan, chloroxylenol, methylisothiazolinone and borax, used in cleaning had genotoxic and histopathologic effects on rainbow trout, Methylisothiazolinone toxicity and inhibition of wound healing and regeneration in planaria, Methylchloroisothiazolinone and/or methylisothiazolinone in cosmetic products, Isothiazolinone Biocides: Chemistry, Biological, and Toxicity Profiles, Methylisothiazolinone and isothiazolinone allergy, Analysis of isothiazolinones in environmental waters by gas chromatography–mass spectrometry, Methylisothiazolinone induces apoptotic cell death via matrix metalloproteinase activation in human bronchial epithelial cells, EU REGULATIONS , Methylisothiazolinone contact allergy: a review, Effects of methylisothiazolinone and octylisothiazolinone on development and thyroid endocrine system in zebrafish larvae, Two Cases of Chloromethylisothiazolinone and Methylisothiazolinone-associated Toxic Lung Injury, An update of the risk assessment for methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) with focus on rinse-off products, Effects of a mixture of chloromethylisothiazolinone and methylisothiazolinone on peripheral airway dysfunction in children, Isothiazolinone preservative: cause of a continuing epidemic of cosmetic dermatitis, Campaign for Safe Cosmetics: Methylisothiazolinone and Methylchloroisothiazolinone
2-Aminoethanol is a colorless, viscous liquid that, despite not being registered for pesticide use in the U.S, holds vast potential in a variety of applications. It can be used in cutting fluids, production of soaps, surfactants, salts, corrosion control inhibitors, pharmaceuticals, and even in protective topical solutions against chemical warfare agents. Used as a pharmaceutical adjuvant, 2-Aminoethanol is effective as a solvent for fats and oils and in creating emulsion formulas like lotions and creams. However, it poses health risks, as a 5.9% concentration can irritate human skin and inhalation may cause allergic reactions, liver damage, and liver symptoms.
Phosphoric acid, in liquid or solid form, can cause second-degree burns upon contact within minutes. It's usually shipped as a solid or an 85% solution and is corrosive to skin when the concentration is over 70%. This acid is also an irritant to the eyes, skin, and upper respiratory tract, however, the risk of pulmonary edema is minimal.






