By Carol Benton | Published Mar 30, 2022 11:05 AM

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In some homes, the water from the washing machine drains into a septic system that treats the wastewater. A septic-safe laundry detergent doesn’t interfere with how this system functions. In other words, it contains no ingredients that can impede the system’s ability to break down waste.

Of course you want to get your clothes as clean as possible, but for your health and the environment, you may want hypoallergenic, natural, plant-based options. The best detergent for septic systems meets these needs while also properly treating the home’s wastewater.

When a home’s wastewater doesn’t drain into a municipal sewer system, it’s treated in a septic system, which requires monitoring and regular maintenance, even if in good working order. For example, every 2 to 3 years, a septic tank should be pumped.

To maintain optimal functioning, users should avoid putting harmful substances into their septic systems, including chemicals that interfere with the beneficial bacteria that break down waste and substances that can build up excessive sludge. Consider the following factors when choosing the best detergents for septic systems.

For septic tanks, the debate over powdered versus liquid laundry detergent is ongoing. However, the difference between powder and liquid is not as important as the ingredients in the detergent.

Powdered detergents may contain fillers such as clay or powdered plastics, which can build up in the septic tank and cause clogging. Biodegradable laundry detergent powders don’t cause that buildup.

Liquid detergents also should be biodegradable. It’s especially important to avoid chlorine bleach and other harsh chemicals, which can kill the helpful bacteria in the septic tank that break down waste.

A “septic-safe” laundry detergent contains no ingredients that interfere with the function of the on-site system to treat waste.

To maintain an optimal balance in bacteria and enzymes that break down waste, choose septic-safe detergents. Avoid detergents that contain these ingredients:

Safe alternatives include low-sudsing biodegradable detergents that contain plant-based cleaning agents. Scents from essential oils don’t pose a hazard to the septic system. Green or eco-friendly detergents are among the best soaps for septic systems.

A “surfactant,” a term that comes from the phrase “surface-active agent,” consists of amphiphilic molecules that are absorbed in the air-water interface. This absorption results in a decrease in surface tensions, facilitating the detergent’s ability to spread and soak into fabrics in the laundry.

The decrease in surface tensions yields the desired cleaning effect, as dirt is wicked away. Because of surfactants, laundry detergents appear to lift soil and stains from clothing and household linens.

Chemical- and petroleum-based surfactants may harm a septic system by building up sludge. Plant-based surfactants are both septic-safe and effective cleaning agents. The best plant-based surfactants derive from palm oil, coconut oil, and soap nuts (soap berries).

Manufacturers of eco-friendly laundry detergents focus on not harming the environment during the production, packaging, and use of their products. As a result, natural plant-based cleaning agents are recyclable and come in biodegradable packaging. Moreover, they try to consume less energy during their production processes.

Certain harmful chemicals are notably absent from eco-friendly, biodegradable laundry detergents, such as phosphates; phthalates; 1,4-Dioxane; chemical fragrances; synthetic brightener; and more. Instead, effective biodegradable cleaning ingredients often are derived from plants. Plant-based cleaning agents in biodegradable detergents offer hypoallergenic properties that benefit those with sensitive skin.

A concentrated liquid laundry detergent contains less water in its formula than non-concentrated liquid detergents. Consequently, it takes a smaller amount of the concentrated liquid to produce optimal cleaning results.

Concentrated formulas may be economical because a little goes a long way. Users should get more laundry loads from a bottle of concentrated-liquid detergent than from the same-size bottle of non-concentrated liquid.

Because it’s difficult to estimate the correct amount of concentrated detergent, users may use too much. Excess detergent creates a residue on clothes as well as a buildup that may be harmful to high-efficiency washers. Always follow the manufacturer’s directions when measuring liquid detergent.

We researched the best laundry detergents for septic systems and developed a list of recommendations. We selected concentrated liquids, powders, and pods, including eco-friendly, biodegradable, and hypoallergenic options. Keep reading to learn about our top picks.

Best Overall1 Arm & Hammer Sensitive Skin Free & Clear Liquid Photo: amazon.com Check Latest PriceThe Arm & Hammer company started in 1846 when its founders began preparing and selling bicarbonate of soda, known today as baking soda. Over the years, this well-respected company diversified its product line to include laundry detergents. Sensitive Skin Free & Clear laundry detergent is free of dyes, preservatives, and fragrance; however, it contains stain-fighting ingredients. As an added bonus, this detergent works with less water than the previous formula. Arm & Hammer laundry detergent is especially beneficial for people with sensitive skin. With no dye, fragrance, or preservatives, it’s hypoallergenic. To authenticate it, the company participated in clinical tests conducted by health-care professionals and dermatologists. Product SpecsFormulation type: Concentrated liquidFree of these ingredients: Dyes, perfumes, fragrance, preservatives, enzymes, sulfatesScent: None ProsReputable, well-known manufacturerHypoallergenicUses less waterRemoves stains ConsSome may not prefer its fragrance-free formula Get Arm & Hammer laundry detergent on Amazon, at Rite Aid, or at Kroger.Best Bang for the Buck2 Mrs. Meyer’s Liquid Laundry Detergent Photo: amazon.com Check Latest PriceUsing a formula that depends on plant-based ingredients for cleaning power, Mrs. Meyer’s Clean Day laundry detergent is both safe and effective. After 28 days, it’s biodegradable, so it won’t harm septic systems. For this concentrated-liquid detergent, the manufacturer derives the surfactants and stain-fighting enzymes from plant sources, not chemicals. Mrs. Meyer’s cleaning products come in light, herbal, and floral scents. Moreover, Mrs. Meyer’s Clean Day laundry detergent has aromatherapeutic benefits. With essential oils in its formula, this detergent is available in five scents, including basil, lemon verbena, lavender, geranium, and honeysuckle. Product SpecsFormulation type: ConcentratedFree of these Ingredients: Parabens, phthalates, artificial colors, optical brightenersScents: Lemon verbena and 4 additional essential oil–based scents ProsBiodegradablePlant-based surfactantsLight scentsCompany contributes to environmental preservation ConsScents may be too strong for some Get Mrs. Meyer’s laundry detergent on Amazon, at Target, or at Mrs. Meyer’s. Best Liquid Concentrate3 Tide Purclean Plant-Based EPA Safer Choice Photo: amazon.com Check Latest PriceSince 1946, when it introduced Tide laundry detergent, Procter & Gamble has been a reliable and well-respected brand in households throughout the United States. The Tide Purclean product introduces a formula made from plant-based cleaning agents. It’s labeled as a USDA Certified Bio-Based Product. The manufacturer of Tide Purclean takes several steps to ensure environmentally friendly practices. The product is packed in a recyclable box with a no-drip tap and dosing cup that uses 50 percent less plastic than typical bottles of detergent. Additionally, the formula is made using electricity that is 100 percent derived from wind power. Tide Purclean contains plant-based ingredients that won’t harm septic systems. The cleaning agents, solvents, suds reducers, and water softeners are derived from plants. Product Specs Formulation type: Concentrated liquidFree of these ingredients: Dyes, phosphates, chlorine bleach, brightenersScent: Honey lavender ProsPlant-based solvents and enzymesPlant-based water softenerPackaging uses 50 percent less plasticDetergent uses 30 percent less water ConsScent may be too strong for someSome users may not like the “eco-box” with dispenser tap Get Tide laundry detergent on Amazon, at Target, or at Walmart. Best Powder4 Charlie’s Soap Laundry Powder Photo: amazon.com Check Latest PriceSome users prefer a powdered detergent because it’s more convenient and less messy than liquid. Charlie’s Soap offers the convenience of a powder along with biodegradable, nontoxic, and septic-safe properties. Charlie’s Soap uses surfactants from plant sources to deliver eco-friendly cleaning power. It’s nontoxic and safe for baby clothes as well as large, dirty laundry loads. The formula includes washing soda along with other natural ingredients to clean the tough stains from grease, grass, red wine, and more. As an EPA Safer Choice Certified product, Charlie’s Soap is safe for people, the environment, and septic systems. Additionally, it works well for high-tech and delicate fabrics. Users with sensitive skin will appreciate its hypoallergenic and fragrance-free qualities. Product Specs Formulation type: PowderFree of these ingredients: Sulfates, fragranceScent: None ProsPlant-based ingredientsEPA Safer Choice CertifiedHypoallergenicFragrance-free ConsSome may not prefer its fragrance-free formula Get Charlie’s Soap laundry powder on Amazon, Charlie’s Soap, or at Walmart. Best Pods5 Seventh Generation Laundry Detergent Packs Photo: amazon.com Check Latest PriceLaundry detergent pods have an advantage over liquids and powders: no measuring. Simply add a pack (pod) to the washing machine when loading laundry. The outer coating dissolves in water to release the detergent inside. Seventh Generation laundry packs dissolve quickly in both hot and cold water in high-efficiency and standard washing machines. The Seventh Generation formula activates triple enzymes to remove stains such as spaghetti sauce, coffee, and other messy substances. Seventh Generation laundry detergent packs are certified as a U.S. EPA Safer Choice product, which signifies that they are safe for both human health and the environment, including septic systems. The detergent in the packs contains no dyes, fragrances, or artificial brighteners, making it safe for sensitive skin. Product SpecsFormulation type: Pod (pack)Free of these ingredients: Dyes, fragrances, artificial brightenersScent: None ProsConvenientDissolves quicklySafe for sensitive skinStain-removing formula ConsOuter coating of pod may not dissolve completelyFragrance-free Get Seventh Generation laundry detergent packs on Amazon, at Target, or at Walmart. Best Biodegradable6 Method Liquid Laundry Detergent Photo: amazon.com Check Latest PriceFounded in 2001, the Method company is known for producing high-quality products that not only clean laundry but also homes, bodies, and dishes. This concentrated liquid laundry detergent is biodegradable and safe for septic systems. Additionally, it’s hypoallergenic, making it safe for those with sensitive skin. This scented detergent employs plant-based ingredients to lift dirt and stains from fabrics. Colors stay bright, and whites stay white. Method detergent works well in high-efficiency as well as standard machines. The company is committed to cruelty-free product development, so their formulas are never tested on animals. Method’s founders created the company with a vision to engage in environmental preservation as well as in positive social practices. Product SpecsFormulation type: Concentrated liquidFree of these ingredients: Phosphates, hydrocarbons, phthalates, parabensScents: Lavender, cyprus, and 5 additional scents ProsBiodegradableHypoallergenicCruelty-free6 nature-inspired scents ConsScents may be too strong for some Get Method laundry detergent on Amazon, at Kroger, or at Walgreens. Best Echo-Friendly7 Biokleen Free & Clear Natural Laundry Detergent Photo: amazon.com Check Latest PriceWith no fragrances, dyes, or pollutants, this natural biodegradable detergent is healthy for a septic system as well as for sensitive skin. Moreover, Biokleen detergent is healthy for the environment. Starting in the 1980s, company founder Jim Rimer created nontoxic cleaning products safe for both humans and the environment. Today, Biokleen Free & Clear natural laundry detergent uses mineral-based cleaning agents and chlorine-free oxygen bleach to deliver effective cleaning results without harming the planet. This detergent works in both high-efficiency and standard washing machines. The mineral-based cleaning agents lift out dirt and stains and rinse clean, leaving no residue. Chlorine-free oxygen bleach ensures colors stay bright and whites remain white. Product Specs Formulation type: PowderFree of these ingredients: Phosphates, chlorine, ammonia, petroleum solvents, butyl, glycol ether, artificial brighteners, artificial fragrance, pollutants, hazardous materialsScent: None ProsBiodegradableHypoallergenicChlorine-free oxygen bleachNever tested on animals Cons  Fragrance-free Get Biokleen laundry detergent on Amazon or at Biokleen. Best Hypoallergenic8 ECOS Hypoallergenic Laundry Detergent Photo: amazon.com Check Latest PriceSkin irritation caused by laundry detergents is not uncommon. For those with sensitive skin, ECOS hypoallergenic laundry detergent may provide relief from the itching and redness caused by the chemicals in other laundry detergents. It contains plant-derived cleaners, with coconut oil as the featured ingredient along with essential oils for fragrance. ECOS is free of allergy-causing chemicals such as 1,4-Dioxane; dyes; phthalates; and more. Additionally, it’s pH balanced to be gentle on sensitive skin. This detergent is kind to animals and the environment as well as to humans. Made from 100 percent vegan ingredients, it’s certified by the U.S. Environmental Protection Agency as a Safer Choice product. Moreover, ECOS is made in a carbon-neutral and water-neutral factory using 100 percent renewable energy. Product Specs Formulation type: LiquidFree of these ingredients: Dyes, formaldehyde, phthalates, parabens, phosphates, optical brighteners, harsh chemicalsScents: Magnolia and lily Pros100 percent veganDermatologist-tested hypoallergenicPlant-derived cleaning agentsEPA Safer Choice certified ConsScents not attractive to some Get ECOS laundry detergent on Amazon or at ECOS. Best Natural Organic9 Dr. Bronner’s - Pure-Castile Liquid Soap Photo: amazon.com Check Latest PriceIn 1948, Dr. Bronner was a third-generation master soap maker when he launched the company that sells Dr. Bronner’s Pure-Castile Liquid Soap. Today, it’s still made from 90 percent organic natural oils. Additionally, more than 70 percent of the soap’s ingredients are certified Fair Trade, which means that the company adheres to guidelines for ethical working conditions and fair prices. The all-natural vegan ingredients in this soap are fully biodegradable, so they’re safe for septic systems. Dr. Bronner’s pure-castile soap is three times more concentrated than most liquid detergents, so a little goes a long way. When diluted, it can be used to wash dishes and household surfaces as well as laundry. Product SpecsFormulation type: Concentrated liquidFree of these ingredients: Synthetic preservatives, synthetic detergents, foaming agents, thickenersScent: None ProsBiodegradableCertified under U.S. Department of Agriculture (USDA) National Organic ProgramAll-natural, vegan, organicVersatile ConsAlthough labeled “unscented,” slight scent from natural ingredients Get Dr. Bronner’s liquid soap on Amazon, at Dr. Bronner’s, or at Target. Best For Stains10 Dropps Stain & Odor Laundry Detergent Pods Photo: amazon.com Check Latest PriceThe formula for Dropps laundry detergent pods focuses on sustainable, plant-based, and nontoxic ingredients to battle laundry stains and odors. The company pledges to help users keep their clothes smelling fresh and to remove unsightly, stubborn stains from fabrics. The pods are available in four scents as well as in an unscented option. Dropps detergent pods work well in all types of washing machines, including high-efficiency models and standard machines, top loaders, and front loaders. They’re free from synthetic fragrances and dyes, as well as phthalates, phosphates, enzymes, and parabens. Consequently, the pods are safe for septic systems. In addition to ensuring high-quality standards for their laundry detergent pods, Dropps uses low-waste packaging. The pods ship in recyclable, compostable cardboard boxes. Product Specs Formulation type: PodsFree of these ingredients: Synthetic fragrances, dyes, enzymes, optical brighteners, parabens, phosphates, phthalatesScents: Lavender eucalyptus, 3 other scents, or unscented ProsPlant-based ingredientsFormulated for stains and odorsPackaged in a recyclable cardboard boxNo synthetic dyes or fragrances ConsPods don’t always dissolve completelyStore in glass or plastic in humid environments Get Dropps laundry detergent pods on Amazon, at Dropps, or at Walmart.

The Arm & Hammer company started in 1846 when its founders began preparing and selling bicarbonate of soda, known today as baking soda. Over the years, this well-respected company diversified its product line to include laundry detergents.

Sensitive Skin Free & Clear laundry detergent is free of dyes, preservatives, and fragrance; however, it contains stain-fighting ingredients. As an added bonus, this detergent works with less water than the previous formula.

Arm & Hammer laundry detergent is especially beneficial for people with sensitive skin. With no dye, fragrance, or preservatives, it’s hypoallergenic. To authenticate it, the company participated in clinical tests conducted by health-care professionals and dermatologists.

Get Arm & Hammer laundry detergent on Amazon, at Rite Aid, or at Kroger.

Using a formula that depends on plant-based ingredients for cleaning power, Mrs. Meyer’s Clean Day laundry detergent is both safe and effective. After 28 days, it’s biodegradable, so it won’t harm septic systems.

For this concentrated-liquid detergent, the manufacturer derives the surfactants and stain-fighting enzymes from plant sources, not chemicals. Mrs. Meyer’s cleaning products come in light, herbal, and floral scents.

Moreover, Mrs. Meyer’s Clean Day laundry detergent has aromatherapeutic benefits. With essential oils in its formula, this detergent is available in five scents, including basil, lemon verbena, lavender, geranium, and honeysuckle.

Get Mrs. Meyer’s laundry detergent on Amazon, at Target, or at Mrs. Meyer’s.

Since 1946, when it introduced Tide laundry detergent, Procter & Gamble has been a reliable and well-respected brand in households throughout the United States. The Tide Purclean product introduces a formula made from plant-based cleaning agents. It’s labeled as a USDA Certified Bio-Based Product.

The manufacturer of Tide Purclean takes several steps to ensure environmentally friendly practices. The product is packed in a recyclable box with a no-drip tap and dosing cup that uses 50 percent less plastic than typical bottles of detergent. Additionally, the formula is made using electricity that is 100 percent derived from wind power.

Tide Purclean contains plant-based ingredients that won’t harm septic systems. The cleaning agents, solvents, suds reducers, and water softeners are derived from plants.

Get Tide laundry detergent on Amazon, at Target, or at Walmart.

Some users prefer a powdered detergent because it’s more convenient and less messy than liquid. Charlie’s Soap offers the convenience of a powder along with biodegradable, nontoxic, and septic-safe properties.

Charlie’s Soap uses surfactants from plant sources to deliver eco-friendly cleaning power. It’s nontoxic and safe for baby clothes as well as large, dirty laundry loads. The formula includes washing soda along with other natural ingredients to clean the tough stains from grease, grass, red wine, and more.

As an EPA Safer Choice Certified product, Charlie’s Soap is safe for people, the environment, and septic systems. Additionally, it works well for high-tech and delicate fabrics. Users with sensitive skin will appreciate its hypoallergenic and fragrance-free qualities.

Get Charlie’s Soap laundry powder on Amazon, Charlie’s Soap, or at Walmart.

Laundry detergent pods have an advantage over liquids and powders: no measuring. Simply add a pack (pod) to the washing machine when loading laundry. The outer coating dissolves in water to release the detergent inside.

Seventh Generation laundry packs dissolve quickly in both hot and cold water in high-efficiency and standard washing machines. The Seventh Generation formula activates triple enzymes to remove stains such as spaghetti sauce, coffee, and other messy substances.

Seventh Generation laundry detergent packs are certified as a U.S. EPA Safer Choice product, which signifies that they are safe for both human health and the environment, including septic systems. The detergent in the packs contains no dyes, fragrances, or artificial brighteners, making it safe for sensitive skin.

Get Seventh Generation laundry detergent packs on Amazon, at Target, or at Walmart.

Founded in 2001, the Method company is known for producing high-quality products that not only clean laundry but also homes, bodies, and dishes. This concentrated liquid laundry detergent is biodegradable and safe for septic systems. Additionally, it’s hypoallergenic, making it safe for those with sensitive skin.

This scented detergent employs plant-based ingredients to lift dirt and stains from fabrics. Colors stay bright, and whites stay white. Method detergent works well in high-efficiency as well as standard machines.

The company is committed to cruelty-free product development, so their formulas are never tested on animals. Method’s founders created the company with a vision to engage in environmental preservation as well as in positive social practices.

Get Method laundry detergent on Amazon, at Kroger, or at Walgreens.

With no fragrances, dyes, or pollutants, this natural biodegradable detergent is healthy for a septic system as well as for sensitive skin. Moreover, Biokleen detergent is healthy for the environment.

Starting in the 1980s, company founder Jim Rimer created nontoxic cleaning products safe for both humans and the environment. Today, Biokleen Free & Clear natural laundry detergent uses mineral-based cleaning agents and chlorine-free oxygen bleach to deliver effective cleaning results without harming the planet.

This detergent works in both high-efficiency and standard washing machines. The mineral-based cleaning agents lift out dirt and stains and rinse clean, leaving no residue. Chlorine-free oxygen bleach ensures colors stay bright and whites remain white.

Get Biokleen laundry detergent on Amazon or at Biokleen.

Skin irritation caused by laundry detergents is not uncommon. For those with sensitive skin, ECOS hypoallergenic laundry detergent may provide relief from the itching and redness caused by the chemicals in other laundry detergents. It contains plant-derived cleaners, with coconut oil as the featured ingredient along with essential oils for fragrance.

ECOS is free of allergy-causing chemicals such as 1,4-Dioxane; dyes; phthalates; and more. Additionally, it’s pH balanced to be gentle on sensitive skin.

This detergent is kind to animals and the environment as well as to humans. Made from 100 percent vegan ingredients, it’s certified by the U.S. Environmental Protection Agency as a Safer Choice product. Moreover, ECOS is made in a carbon-neutral and water-neutral factory using 100 percent renewable energy.

Get ECOS laundry detergent on Amazon or at ECOS.

In 1948, Dr. Bronner was a third-generation master soap maker when he launched the company that sells Dr. Bronner’s Pure-Castile Liquid Soap.

Today, it’s still made from 90 percent organic natural oils. Additionally, more than 70 percent of the soap’s ingredients are certified Fair Trade, which means that the company adheres to guidelines for ethical working conditions and fair prices.

The all-natural vegan ingredients in this soap are fully biodegradable, so they’re safe for septic systems. Dr. Bronner’s pure-castile soap is three times more concentrated than most liquid detergents, so a little goes a long way. When diluted, it can be used to wash dishes and household surfaces as well as laundry.

Get Dr. Bronner’s liquid soap on Amazon, at Dr. Bronner’s, or at Target.

The formula for Dropps laundry detergent pods focuses on sustainable, plant-based, and nontoxic ingredients to battle laundry stains and odors. The company pledges to help users keep their clothes smelling fresh and to remove unsightly, stubborn stains from fabrics. The pods are available in four scents as well as in an unscented option.

Dropps detergent pods work well in all types of washing machines, including high-efficiency models and standard machines, top loaders, and front loaders. They’re free from synthetic fragrances and dyes, as well as phthalates, phosphates, enzymes, and parabens. Consequently, the pods are safe for septic systems.

In addition to ensuring high-quality standards for their laundry detergent pods, Dropps uses low-waste packaging. The pods ship in recyclable, compostable cardboard boxes.

Get Dropps laundry detergent pods on Amazon, at Dropps, or at Walmart.

Our top recommendations include Arm & Hammer Sensitive Skin Free & Clear laundry detergent as well as Mrs. Meyer’s Liquid Laundry Detergent. For value, reputation, and safety for septic systems, these two products stand out.

To develop a list of recommended septic-safe laundry detergents, we considered how septic systems function and their proper maintenance and treatment. Next, we read nine articles containing background information and product reviews. From there, we perused the product descriptions for 18 different laundry detergents to arrive at our list of recommended products.

We focused on laundry detergents with biodegradable and plant-based ingredients that remain safe in septic systems. Many of these choices also exhibit hypoallergenic and eco-friendly properties. Understanding that shoppers prefer a variety of products, we included both scented and unscented choices as well as liquids, powders, and pods. Finally, we considered brand reputation, focusing on manufacturers that enjoy a strong reputation for high-quality products.

Those whose home wastewater empties into a septic tank must consider the health and function of the system when selecting laundry detergent. The right kind of product may assist in the long-term maintenance and smooth operation of the system. Keep reading to see a few questions and answers about the best laundry soap for septic systems.

As long as the ingredients are fully biodegradable, detergent pods may be used safely without harming septic systems.

To break down waste, useful bacteria must thrive in a septic system, and overuse of chlorine bleach may kill off the bacteria. Avoid products that contain chlorine bleach.

Keep a septic system healthy by having it cleaned (pumped out) every 2 to 3 years or when sludge fills the tank to one-third of its depth. Begin using a laundry detergent designated safe for septic systems.

Avoid chlorine bleach, ammonia, and phosphates. Also avoid overusing chemical-based cleaners; instead, look for biodegradable plant-based products.

Perform regular inspections and maintenance, such as pumping the tank when needed (or every 2 to 3 years). Keep the septic tank lid closed, secured, and readily accessible.

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