Are Laundry Scent Boosters Toxic? (+Safe Brands)

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Toxicity Review – All Brands As a Whole

Summary

Of the conventional products analyzed, Snuggle In Wash Scent Beads was by far the “safest” from a chemical standpoint based on the number of ingredients that had health concerns primarily.

There were no chemicals of high level concern for humans.

If you want an all-natural option Good Laundry Scent Booster Beads are all-natural, made of corn start and natural fragrance. I tested them and the staying power was quite good.

Though all mainstream brands I looked at contain ingredients that are allergens (all-natural brands almost certainly will as well),

All of the mainstream brands we looked at also contain ingredients with environmental toxicity concerns.

In term of the other brands we analyzed (apart from Snuggle and Good Laundry) they contained ingredients that are flagged as carcinogenic or potentially carcinogenic (or potentially contaminated with potential carcinogens), potential endocrine disrupters, expected to be toxic or harmful (organ toxicity, non-reproductive), ingredients on the California toxic air contaminants list, ingredients that were mutagenic, or reproductive toxicant, or ingredients on the the Canadian persistent, bioaccumulative, and toxic substances list.

Toxicity Review of Individual Brands

Note: While I prefer to use products without ingredients that cause aquatic toxicity, or have carcinogenic, endocrine disruptors or other human health effects myself, these classifications reflect laboratory tests on individual chemicals, not formulated products. These classifications describe how hazardous each ingredient may be on its own, not the actual risk to you from using the product.¹

Top Pick Out of The Conventional Brands

Snuggle Scent Beads

Out of all the mainstream brands that I looked at Snuggle Scent Beads have by far the “cleanest” ingredient list in terms of human health.

And they are 95% natural:

Fragrance

• Allergens: 5
• Myrac Aldehyde is on the Chemicals that are identified as persistent, bioaccumulative, and inherently toxic to the environment by the Canadian Environmental Protection Act Environmental Registry Domestic Substances List.
• Fragrances ingredients that is toxic to aquatic life are the natural limonenes and terpenes.
  • Limonene and linalool are common fragrance ingredients that can trigger skin reactions in sensitive individuals, not because of the compounds themselves, but because of what they break down when exposed to air.
• It contains Denatonium benzoate – this ingredient is listed as Long-term (chronic) aquatic hazard (Category 3), H412 on safety data sheets. (But the pay off is to prevent accidental ingestion by children).

There are no ingredients that are high level harmful to human health in this scent that I looked at (Lavender).

In other words, Snuggle Scent Beads formula does not appear to contain ingredients classified as carcinogenic, mutagenic, reproductive toxicants, endocrine disruptors, respiratory sensitizers, substances with high acute toxicity to humans, or substances causing serious target organ toxicity to humans at typical exposure levels.

Top Pick – Natural Brand

For those who prefer natural scents, Good Laundry Scent Booster Beads are all-natural, made of corn start and natural fragrance.

I tested these and the scent was stronger than what I would expect from something all-natural, for example when comparing it to spraying essential oils on my sheets.

It also had more staying power than essential oils.

Other Mainstream Brands Analyzed

1. Downy Unstopables In Wash Scent Booster Beads

Potentially Problematic Ingredients to Examine:

1. PEG (Perfume Carrier) CAS 25322-68-3
   • PEG can be contaminated with potentially carcinogenic impurities like 1,4-dioxane and ethylene oxide, however….
     • For 1,4 Dioxane: Because Downy Unstopables do not have Prop 65 warning this means if they do contain 1,4 dioxane, it’s below the level required by Prop 65 and therefore it “will not pose a significant risk of cancer or reproductive harm” according to Prop 65.
     • They also comply with New York state laws on 1,4-dioxane which allow for only 1 part per million.
   • Ethylene oxide is also a Prop 65 chemical due to cancer and reproductive toxicity, but here it is also below the Prop 65 threshold. So it “will not pose a significant risk of cancer or reproductive harm” according to Prop 65.
     • The New Jersey government says, in relation to ethylene oxide, “there may be no safe level of exposure to carcinogens”.
     • Keep in mind PEG is used in food, medications and many household products. And, contrary to what some bloggers are saying, it is not banned in Europe (source).
2. Fragrances, listed out fully here

• All known ingredients are rated C or D by EWG* (which is not great).
• Allergens: some are fragrance allergens.
• Health: two have potential endocrine effects (one is a weak phytoestrogen which is not really a concern here, the other is a potential endocrine disrupter).
• Environment: one is classified as expected to be toxic or harmful (organ toxicity, non-reproductive) by Environment Canada; some have aquatic toxicity.
• 3. Dyes: In the Lush scent, one has a C rating (EWG), the other is an azo dye but is not flagged as hazardous.

2. Downy Light Scent Beads

• Downy Light Scent Beads have a lighter scent than the Unstopables (“no heavy perfumes” they say).
• The scents are more inspired by natural scents, and they are dye-free.Like Unstopables, they are based on PEG and a mix of synthetic and natural fragrance ingredients.
• Having reviewed Downy light and Downy regular scent beads’ ingredient lists in full, we are not able to tell a difference in one being “more natural”, i.e. containing significantly more natural ingredients than the other, because we don’t actually know what percent of each ingredient is used.
• We also cannot tell if there is a major difference between the two in terms of safety of ingredients, again, that depends on their percentages, which we don’t know.

3. Gain Fireworks Scent Beads

Potentially Problematic Ingredients to Examine:

1. PEG (Perfume Carrier) CAS 25322-68-3
   • PEG can be contaminated with potentially carcinogenic impurities like 1,4-dioxane and ethylene oxide, however….
     • For 1,4 Dioxane: Gain Fireworks do not have a Prop 65 warning so 1,4 dioxane, if present, would not be considered to be at a level of concern.
     • They comply with New York state laws on 1,4-dioxane with allow for only 1 part per million (less than the Prop 65 threshold).
     • Ethylene oxide is also a Prop 65 chemical due to cancer and reproductive toxicity, but here it is also below the Prop 65 threshold. So it “will not pose a significant risk of cancer or reproductive harm” according to Prop 65.
       • The New Jersey government says, in relation to ethylene oxide, “there may be no safe level of exposure to carcinogens”.
       • Keep in mind PEG is used in food, medications and many household products. And, contrary to what some bloggers are saying, it is not banned in Europe (source).
2. Methyl Di-t-butyl Hydroxyhydrocinnamate
   • Has environmental concerns (source). Direct toxicity data on this antioxidant ingredient is limited, but the available evidence points to a low environmental risk and no significant accumulation in wildlife or the food chain, says Carlos Roque, toxicologist.
3. Colorants – polyoxyalkylene substituted chromophore (yellow).
   • We don’t have enough information to analyze it.
4. Fragrance
   • Allergens: six ingredients on the EU fragrance allergen list.
   • Health: butylphenyl methylpropional is on the EU CMRs list, which means that it is identified as a carcinogenic, mutagenic, or reproductive toxicant.
   • Lilial (butylphenyl methylpropional) is banned in EU cosmetics due to reproductive toxicity concerns, but it remains permitted in household products.
   • Environment: Diphenyl ether is considered very toxic to aquatic life (source) and Iso-alpha-Methyl Ionone is toxic to aquatic life (source).

4. Arm and Hammer Clean Scentsations In-Wash Scent Booster

Potentially Problematic Ingredients to Examine:

1. Dyes – the dyes here are not listed out precisely. They list the categories of Polyoxyalkylene substituted chromophore (cyan) and Polyoxyalkylene substituted chromophore (blue).
   • We don’t have enough information to analyze it.
2. Fragrance
   • Allergens: There are three fragrance ingredients that are on the EU fragrance allergen list. That does not mean that they’re toxic, but they are skin allergens for some people.
   • Health: There is one ingredient, butylphenyl methylpropional, that is on the EU CMRs list, which means that it is identified as a carcinogenic, mutagenic, or reproductive toxicant.
   • And we have one ingredient in the IARC Carcinogenic list – Isoeugenol. The main concern with isoeugenol is skin reactions from direct contact, not internal harm at the trace levels typically found in air fresheners or laundry products, says Carlos Roque toxicologist.
   • Air Quality: There is one ingredient, acetophenone, that’s is on California’s toxic air contaminants list, but current safety assessments confirm it does not pose a relevant health risk at typical fragrance use concentrations.

5. Purex Crystals

Potentially Problematic Ingredients to Examine:

1. 1. Colorants – Polymeric Colorant – blue – vague chemical category, it’s not possible to assess the toxicity without more details about what this is.
2. 2. Fragrance
   • Allergens: 3 fragrance allergens.
   • The Environment: 10 ingredients are identified as persistent, bioaccumulative, and inherently toxic to the environment by the Canadian Environmental Protection Act Environmental Registry Domestic Substances List: 2-(4-methylcyclohexyl)propan-2-yl acetate, alpha-methyl ionone, ambroxan, p-methyl acetophenone, (4-methylphenyl) 2-phenylacetate, Alpha-Isomethyl Ionone, 2-phenylethyl 2-hydroxybenzoate, (E)-undec-2-enal, nerolidol, 3,7-dimethyloct-6-enyl (E)-2-methylbut-2-enoate.
     • 2-cyclohexylidene-2-phenylacetonitrile, Diphenyl ether, and Benzyl acetate all have environmental toxicity concerns based on their individual SDS sheets.
     • Denatonium benzoate – this ingredient is listed as Long-term (chronic) aquatic hazard (Category 3), H412 on safety data sheets. (But the pay off here is to prevent accidental ingestion by children).
   • Air Quality: One chemical is identified as a toxic air contaminants in California Code of Regulations – acetophenone, but current safety assessments confirm it does not pose a relevant health risk at typical fragrance use concentrations, says Carlos Roque, toxicologist.
   • Health: Hexyl salicylate is classified as a Carcinogenic, Mutagenic, or Reprotoxic (CMR) category 2 substance under the GB Classification (source).
3. 3. PEG (Perfume Carrier) CAS 25322-68-3
   • PEG can be contaminated with potentially carcinogenic impurities like 1,4-dioxane and ethylene oxide, however….
     • For 1,4 Dioxane: Purex Crystals do not have Prop 65 warning so 1,4 dioxane, if present, would not be considered to be at a level of concern.
     • They comply with New York state laws on 1,4-dioxane with allow for only 1 part per million (less than the Prop 65 threshold).
     • Ethylene oxide is also a Prop 65 chemical due to cancer and reproductive toxicity, but here it is also below the Prop 65 threshold. So it “will not pose a significant risk of cancer or reproductive harm” according to Prop 65.
       • The New Jersey government says, in relation to ethylene oxide, “there may be no safe level of exposure to carcinogens”.
       • Keep in mind PEG is used in food, medications and many household products. And, contrary to what some bloggers are saying, it is not banned in Europe (source).

6. Dreft Blissfuls In-Wash Scent Booster

1. 1. PEG CAS 25322-68-3
   • PEG can be contaminated with potentially carcinogenic impurities like 1,4-dioxane and ethylene oxide, however….
     • For 1,4 Dioxane: Dreft Blissfuls do not have Prop 65 warning so 1,4 dioxane, if present, would not be considered to be at a level to cause concern.
     • They comply with New York state laws on 1,4-dioxane with allow for only 1 part per million (less than the Prop 65 threshold).
     • Ethylene oxide is also a Prop 65 chemical due to cancer and reproductive toxicity, but here it is also below the Prop 65 threshold. So it “will not pose a significant risk of cancer or reproductive harm” according to Prop 65.
       • The New Jersey government says, in relation to ethylene oxide, “there may be no safe level of exposure to carcinogens”.
       • Keep in mind PEG is used in food, medications and many household products. And, contrary to what some bloggers are saying, it is not banned in Europe (source).
2. 2. Fragrance Ingredients
   • 1,6-octadiene, 7-methyl-3-methylene R IARC Carcinogens.
   • Acetophenone and propanoic acid, 2-methyl-, 2-phenoxyethyl ester are on the California Toxic Air Contaminants list.
   • Allergens: 11
   • Hydrogenated rosin is on the Canadian persistent, bioaccumulative, and toxic substances list.
   • T-butyl alcohol is on California’s drinking-water Notification Level list.
   • There are aquatic toxicity concerns for: tetramethyl acetylactehydronaphthalene, Benzyl Salicylate, Benzyl Benzoate, Benzyl acetate, and Geranyl Acetate.

Are Scent Boosters Septic Safe?

All of the companies I contacted – Downy, Snuggle, Dreft, Purex, and Arm & Hammer – said their scent beads are septic safe when used as directed.

Are Scent Beads Toxic to Dogs and Cats?

Proctor & Gamble said that they have not tested Downy Unstopables on pet bedding, and Purex said that their scent boosters can be used on pet bedding, but they warned about potential sensitivity of some pets.

A toxicologist’s opinion:

Dr. Mudgal says strong synthetic fragrance ingredients and essential oil components like those found in some brands of scent boosters (such as limonene and linalool) are known to be potentially irritating or harmful to some pets, especially cats, if inhaled in large amounts or ingested, says Dr. Mudgal.

We do not have precise data on whether the concentration of ingredients in these products are safe for cats and other common pets.

While the CDC doesn’t specify that you wash pet bedding with anything other regular laundry detergent for most cases (they also don’t specifically address scent boosters here), they say “detergents with no dyes and no fragrance may be a better choice if your pet has sensitive skin.” (source)

The most cautious approach, according to Dr. Mudgal, would be to avoid using heavily scented laundry products on pet bedding or clothing, and keep the scent beads stored safely out of reach.

If a pet chews or eats the beads or shows symptoms after exposure (like vomiting, drooling, or lethargy), consult a veterinarian promptly, says Dr. Mudgal.

References: ASPCA Animal Poison Control Center, Pet Poison Helpline: Essential Oils and Cats – petpoisonhelpline.com, Veterinary Toxicology references (e.g., Handbook of Veterinary Drugs, Gupta).

Are Scent Boosters Safe for Baby Clothes?

There were mixed replies here from companies. Downy moved me away from Unstoppables and towards their Dreft beads, which they said are safe. Henkle who makes Snuggle and Purex beads, first said that fragrance-free products would be better, but they also said Purex beads can be used. Arm & Hammer’s information was equally contradictory (yes, you can use the scent boosters on baby’s clothes, and also they recommend fragrance-free products on the website for babie’s clothes).

A toxicologist’s opinion:

Many scent boosters contain synthetic fragrances, including known allergens like benzyl benzoate, linalool, and limonene.

These are legally permitted, but can sometimes trigger skin irritation, especially in infants with sensitive skin or eczema, says Dr. Mudgal.

The cautious approach that some paediatricians and dermatologists suggest, is using synthetic-fragrance-free laundry products for children (which would include baby clothes). (Source)

Footnotes

1 Hazard and risk are related but different: a hazard is a chemical’s inherent potential to cause harm,
while risk depends on real-world factors – like how much is in the product, how much your body
absorbs, and how much survives washing or wastewater treatment – that are rarely made public.
When a chemical is linked to serious concerns such as cancer, reproductive harm, or hormone
disruption, experts recommend limiting exposure even when full data isn’t available, says Carlos Roque toxicologist.

* The Environmental Working Group (EWG) compiles information from scientific literature,
regulatory databases, and secondary sources. However, its interpretation criteria differ from those
used by regulatory bodies such as the EPA, FDA, EFSA, ECHA, or the NTP, which operate under
formal processes and govern official safety determinations. EWG ratings are best used as a
screening tool to prompt further investigation, not as a standalone measure of safety or risk.

Corinne Segura is an InterNACHI-certified Healthy Homes Inspector with certifications in Building Biology, Healthier Materials and Sustainable Buildings, and more. She has 10 years of experience helping others create healthy homes. You can book a consult here.