Laundry detergents are among the most widely used household products in the world, yet few consumers know exactly what goes into them. Most conventional laundry detergents contain a blend of chemical ingredients that work together to clean clothes, remove stains, and leave fabrics smelling fresh. While these ingredients are effective at cleaning, several have raised concerns around health, environmental safety, and long-term exposure effects.
Surfactants: The Core Cleaning Agents
Surfactants – short for "surface-active agents" – are the primary cleaning components in detergents. These molecules have both hydrophobic (water-repelling) and hydrophilic (water-attracting) ends, allowing them to suspend dirt and oils in water so they can be rinsed away.
One of the most common surfactants in traditional detergents is linear alkylbenzene sulfonate (LAS), an anionic surfactant derived from petroleum. LAS is highly effective at cutting grease but has come under scrutiny due to its slow biodegradation and its potential to cause chronic aquatic toxicity—particularly for algae and invertebrates in surface waters.
Another frequently used group is alcohol ethoxylates, nonionic surfactants valued for their ability to tackle oily soils. While generally effective, these compounds can break down into shorter-chain ethoxylates and acetaldehyde, a known respiratory irritant. Depending on chain length and formulation, some alcohol ethoxylates exhibit acute aquatic toxicity.
Sodium lauryl sulfate (SLS) and sodium laureth sulfate (SLES) are also widely used in both detergents and personal care products. While SLS is a strong cleaner and foamer, it is also a known skin irritant and can damage the skin barrier with repeated exposure. SLES is a milder alternative but is made via a process called ethoxylation, which can leave behind a potentially hazardous byproduct: 1,4-dioxane.
1,4-Dioxane and Ethylene Oxide: Contaminants of Concern
1,4-dioxane is not an intentionally added ingredient but rather a contaminant that can appear in products using ethoxylated surfactants like SLES and PEG compounds. The U.S. Environmental Protection Agency (EPA) classifies 1,4-dioxane as a likely human carcinogen. EWG has flagged it for concerns including digestive system effects, respiratory irritation, and skin allergies.
Similarly, ethylene oxide, a gas used in ethoxylation, is classified as a known human carcinogen by the International Agency for Research on Cancer (IARC). It has been associated with a broad range of health concerns including developmental, endocrine, and reproductive toxicity; DNA damage; organ effects; and vision impairment.
Regulatory action is mounting. New York State now restricts allowable 1,4-dioxane levels in household products, and the EPA is conducting risk evaluations under the Toxic Substances Control Act (TSCA).
Builders: Boosting Performance in Hard Water
Builders are supporting ingredients that enhance cleaning performance by softening water and preventing minerals from interfering with surfactants. One of the earliest and most effective builders was phosphates, which chelate calcium and magnesium ions. However, phosphates have largely been phased out due to their role in waterway pollution. When discharged in wastewater, they contribute to eutrophication, causing algae blooms and oxygen depletion in lakes and rivers.
In place of phosphates, many modern detergents use synthetic alternatives like EDTA (ethylenediaminetetraacetic acid)or NTA (nitrilotriacetic acid). While effective, these substances are not readily biodegradable and may persist in the environment. EDTA, in particular, is considered a micropollutant in European wastewater studies. These compounds can mobilize heavy metals in soil and water and may have chronic effects on aquatic ecosystems.
Other builders include zeolites (aluminosilicate minerals used as phosphate substitutes) and citrate salts, which are more biodegradable and often seen in "greener" formulations.
Fragrance: Signature Scent or Hidden Risk?
Fragrance is one of the most recognizable aspects of conventional detergent—it’s what gives clothes that freshly washed smell. Unfortunately, it’s also one of the most opaque parts of the formula. Under current U.S. regulations, companies can list "fragrance" or "parfum" on a label without disclosing the individual components.
These proprietary blends may include dozens or hundreds of chemicals, including:
- Phthalates, used to make scents last longer, some of which are suspected endocrine disruptors and have been linked to reduced fertility.
- Synthetic musks, which can accumulate in human fat tissue and persist in aquatic environments.
- Allergens and sensitizers, such as limonene or linalool, that may oxidize into more potent irritants upon exposure to air.
Fragrance remains one of the leading causes of skin irritation, allergic reactions, and asthma triggers in fragranced products.
Optical Brighteners: Illusion of Clean
Optical brighteners (also known as fluorescent whitening agents) don’t clean your clothes—they just make them look cleaner. These compounds absorb ultraviolet light and emit blue light, masking yellow tones and giving whites a brighter appearance.
Many conventional detergents use stilbene-based compounds for this purpose. These ingredients are not biodegradable, can bind to fabric fibers, and are toxic to aquatic life, particularly invertebrates and fish. Some optical brighteners can also penetrate the skin and may cause photosensitivity or skin irritation in rare cases.
Preservatives: Extending Shelf Life
Liquid detergents require preservatives to prevent microbial growth. Two common preservatives, methylisothiazolinone (MI) and methylchloroisothiazolinone (MCI), have been associated with contact dermatitis and sensitization, especially in children and individuals with eczema.
Other preservatives, such as formaldehyde-releasing agents (e.g., DMDM hydantoin), are of concern due to formaldehyde’s classification as a probable human carcinogen by the EPA. Low-level exposure has also been associated with respiratory irritation and skin allergies.
Once in wastewater systems, many preservatives are poorly removed by conventional treatment and may contribute to chronic aquatic toxicity.
Solvents and Carriers
To keep liquid detergents stable and effective, manufacturers use a variety of solvents and carriers:
- Propylene glycol, which helps dissolve other ingredients and retain moisture.
- Ethanol, used as a solvent and stabilizer.
- Dipropylene glycol and sorbitol, which also function as humectants or viscosity controllers.
While many of these ingredients are considered safe at low concentrations, they can contribute to indoor air pollution, and certain derivatives may have mild organ system effects upon chronic exposure.
EPA’s 2024 Ban on TCE and PCE
In December 2024, the EPA announced a ban on two industrial solvents – trichloroethylene (TCE) and perchloroethylene (PCE) – citing links to liver and kidney toxicity, cancer, and reproductive harm. While more common in degreasers and dry cleaning solvents, these chemicals may also be present in some heavy-duty cleaning products used in commercial and industrial laundry.
The EPA's decision reflects growing concern over systemic toxicity and groundwater contamination, and underscores the need for rigorous chemical screening in all household and commercial cleaning products.
Ingredient Disclosure and Consumer Tools
In the U.S., laundry detergents are not required to list all ingredients on the product label. However, California’s Cleaning Product Right to Know Act (2017) mandates that manufacturers disclose certain ingredient information online for products sold in the state.
As a result, many companies now provide detailed ingredient disclosures on their websites, though the quality and completeness vary. Consumers can also consult third-party databases such as:
- EWG’s Guide to Healthy Cleaning
- MADE SAFE Certification
- EU Ecolabel or Nordic Swan criteria
These tools offer comparative ingredient safety ratings and product summaries that go beyond the packaging.
Final Thoughts
Understanding the full ingredient list of traditional laundry detergents helps consumers make informed decisions – not just about what works, but about what aligns with personal health values and environmental priorities. While many detergent ingredients are effective and well-tolerated, others may carry risks that aren’t immediately visible on the label. Increasing regulatory scrutiny and consumer demand for transparency are pushing the industry toward safer, more clearly labeled alternatives.
This article is provided for educational purposes and does not promote any specific brand or formulation.