good clean fun
Ingredients
At Wunderkits, we believe wash time should be fun, safe, and worry-free. That’s why we carefully choose every ingredient in our kits to balance creativity, sensory play, and skin-friendly benefits. Explore our ingredient glossary below to learn what goes into our soap, bath fizz, and milk bath kits, and why we use them.
What ingredients are in the melt & pour soap base?
We specifically chose a detergent-free soap base from a U.S. based manufacturer. Many commercial soaps use synthetic detergents (like SLS or SLES) to create lather, but these can be harsh and drying on sensitive skin. By using a detergent-free formula, Wunderkits soaps stay gentle, moisturizing, and kid-friendly, while still producing plenty of bubbly fun.
Ingredients:
Coconut Oil
A natural oil pressed from coconuts. It helps create a creamy lather and leaves skin feeling soft and moisturized.
Glycerin
A plant-derived humectant that draws moisture into the skin, keeping it soft and smooth.
Water
Water is used to dissolve ingredients and create a stable soap base.
Sodium Hydroxide (Saponifying Agent)
A necessary ingredient for turning oils into soap. It is fully reacted during the saponification process and does not remain in the finished soap.
Sorbitol
A sugar alcohol derived from plants that adds clarity and helps soaps feel smooth and moisturizing.
Propylene Glycol
Propylene glycol is a humectant, which means it helps products hold onto moisture and keeps soaps from drying out or crumbling. Some people with very sensitive skin may find it irritating, but it’s generally recognized as safe in cosmetics.
We choose to use a melt-and-pour base with propylene glycol because it keeps the ingredient list simple and stable. Alternatives often rely on harsher chemicals that can be more concerning, so this option allows us to provide a soap base that's easy for kids to use, with fewer trade-offs.
Stearic Acid
Stearic acid is a fatty acid that comes from plant oils (like coconut or palm). It’s often used in skincare and soap because it helps ingredients stick together, gives products a smooth, creamy texture, and makes soaps harder so they last longer. It’s gentle and considered safe for skin, which is why you’ll find it in many natural bath and body products.
Are the colors skin safe & cosmetic grade?
Mica
We use only cosmetic-grade mica that is safe for skin. Most of the shimmering mica you see in soaps and cosmetics starts as naturally mined mica, ground into a silky, pale powder. To get those bold, eye-catching colors, the mica is coated with pigments like iron oxides, ultramarines, or cosmetic-safe dyes.
Here’s the important part: those pigments aren’t naturally mined. They’re made in a lab - on purpose! - to keep out the harmful stuff that can be found in natural pigments, like lead, arsenic, and mercury. The result? Sparkly, vibrant colors that are safe for kids and perfect for creative bath-time fun.
Titanium Dioxide
A naturally occurring mineral used as a white pigment. In soap and bath products, it creates bright, opaque colors and helps lighten or soften other shades.
Black Iron Oxide
An earth-derived pigment that produces deep black tones. It is stable in soap and safe for skin, often used to add contrast or definition in colors.
Fluorphlogopite (Synthetic Mica)
A lab-created alternative to natural mica that delivers extra sparkle and a smoother shimmer. It is considered more consistent and purer than mined mica, while still safe for cosmetic use.
Ultramarine
A mineral pigment that produces rich blue or violet hues. Cosmetic-grade ultramarines are purified for safe use on skin in soap and personal care products.
Tin Dioxide
A mineral-derived whitening and opacifying agent. Often combined with mica to create a pearlescent sheen or brighten colors. Safe for cosmetic applications.
Iron Oxide (Red/Yellow/Brown)
Naturally occurring mineral pigments that provide earthy tones ranging from red to yellow to brown. Highly stable, non-bleeding, and safe for skin.
Manganese Violet
A mineral pigment that creates vibrant purple shades. Cosmetic-grade manganese violet is stable in soapmaking and approved for safe skin use.
Why use biodegradable glitter?
Why we use it
This glitter is eco-friendly, cosmetic-grade, and skin-safe. It sparkles just like traditional glitter, but is designed to break down naturally, so kids get all the fun, without the environmental harm.
Ingredients:
Zea Mays (Corn) Starch
A natural starch derived from corn. It forms the base structure of the glitter, making it biodegradable and plant-based.
Polyvinyl Alcohol (PVA)
A water-soluble, biodegradable polymer used to bind the glitter particles together. It helps the glitter maintain its shape until it naturally breaks down.
Water
Used as part of the binding and film-forming process to hold the glitter ingredients together.
Acrylates Crosspolymer
A cosmetic-safe ingredient that creates a flexible film, helping the glitter remain stable and adhere until it’s washed away.
Aluminum
A thin layer that gives glitter its reflective sparkle. In biodegradable glitter, this coating is applied in a way that allows the product to still break down naturally.
More information:
Our vendor sources the biodegradable glitter from a U.S. manufacturer that employs strict quality standards and is independently tested by third-party laboratories. It meets internationally recognized certifications for safety and biodegradability.
How it’s made
- Created from cellulose derived from eucalyptus trees, a renewable, fast-growing resource.
- Produced in the U.S., keeping its carbon footprint lower than imported glitter.
- Verified through independent lab testing: 91.77% of the material converted to CO₂ in 106 days under ISO 14855 testing (which measures the biodegradation of plastics in soil).
Standards & Certifications
Our glitter complies with globally recognized biodegradability and safety standards, including:
- EC/1223/2009
- EN 17033:2018, 13432, 14995, 16640, 16785-1
- ISO 17088, 15985, 14851
It has also passed independent lab testing for heavy metal safety, meeting EN71:2013 and A2:2017 as well as EU 2017/738.
What dry ingredients are in the bath kits?
Sodium Bicarbonate (Baking Soda)
A gentle, alkaline powder that reacts with citric acid to create the fizzy effect. It also helps soften bath water and can soothe skin.
Citric Acid
A natural fruit acid found in citrus fruits. In bath bombs, it reacts with baking soda to create fizzing bubbles. Safe for skin and commonly used in cosmetics.
Cornstarch (Zea Mays Starch)
Helps bind bath fizzies together and slows down the fizzing reaction, giving a longer-lasting experience in the tub.
Coconut Milk Powder
A finely ground powder made from dried coconut milk. When added to bath water, it dissolves to create a soothing, creamy soak. Coconut milk powder is rich in natural fats that help moisturize and soften the skin, leaving it silky after use. It’s a gentle, plant-based alternative to dairy milk powders and well-suited for sensitive skin.
Why we use it
We chose coconut milk powder instead of dairy-based options because it’s plant-based, gentle on sensitive skin, and suitable for families who prefer vegan-friendly or non-dairy ingredients.
Popping Crystals
Cocoa butter–coated carbonated crystals made with non-GMO ingredients (sugar, lactose, corn syrup solids, cocoa butter, and powdered sugar). The popping effect is created by processing the crystals with carbon dioxide, which makes them crackle and fizz when they come into contact with water.
Why we use it
Popping crystals create a surprising crackling sound that turns bath time into a full sensory experience, not just sight and touch, but sound too. They’re a playful way to add an extra layer of fun while still being completely safe.
Are your oils nut and allergen free?
These ingredients are added to boost skin benefits and make the finished product more luxurious.
Glycerin (tool for mixing soap colors)
Boosts moisture retention and keeps soap feeling gentle and skin-friendly. Also works great to mix with mica powders to eliminate clumps in the finished soap.
Safflower Oil
A lightweight, non-greasy oil pressed from the seeds of the safflower plant. In soap and bath products, it helps keep skin soft and smooth by locking in moisture. It also contributes to a silky lather and is gentle enough for sensitive skin.
Why we use it
We chose safflower oil because it’s considered one of the least allergenic oils. Unlike nut-based or common allergy-triggering oils, safflower oil minimizes the risk of reactions, making it a safer choice for kids’ skin.
Do you have optional ingredients?
These ingredients support the making process as they help bind, blend, or smooth things out during DIY, but they don’t remain in harmful amounts in the finished bath product.
Witch Hazel
A plant-derived extract commonly used in cosmetics. In bath bomb making, it’s used as a natural binder to help ingredients stick together without setting off the fizzing reaction. Witch hazel evaporates as the bath bomb dries, so only a trace remains in the finished product.
Why we use it
Witch hazel allows bath fizzies to hold their shape without crumbling, while avoiding harsher binding agents. It’s a gentle, effective option that makes the DIY process smoother and more kid-friendly.
Isopropyl Alcohol
Used in soap making to help layers stick together and reduce surface bubbles. It evaporates quickly and does not remain in the finished soap.
Why we use it
Isopropyl alcohol helps ensure soaps come out looking smooth and polished, without changing the safety or feel of the final product.
Polysorbate 80
A plant-derived emulsifier commonly used in cosmetics and bath products. It helps oils (like fragrance or essential oils) blend evenly with water, preventing them from floating on the surface. This ensures even distribution of scents and colors in bath fizzies and milk baths, while also reducing residue on the tub.
Why we use it
We include Polysorbate 80 to keep bath time both fun and mess-free. Without it, oils can separate and cling to the skin or tub. Using this gentle emulsifier means fragrances and colors disperse evenly in the water — so kids get the full sensory experience while parents enjoy easier cleanup.
Are your fragrances skin safe and cosmetic grade?
Fragrance is what makes each kit a true sensory experience. We take extra care to ensure the scents we use are safe, gentle, and thoughtfully chosen for kids.
Fragrance Oils (Phthalate-Free)
We use only cosmetic-grade, skin-safe fragrance oils that are 100% phthalate-free. These blends are formulated specifically for use in bath and body products, so they’re gentle on skin while still providing a fun, lasting scent.
Natural Fragrance Oils
Our bath kits feature natural fragrance oils, which are made using naturally derived ingredients. In these blends, specific scent molecules are carefully extracted from plants and then combined to create a consistent, gentle fragrance. Unlike essential oils, which include all of a plant’s aromatic compounds, natural fragrance oils isolate only the safest and most stable components. This makes them less likely to irritate skin, while still offering authentic, nature-inspired scents.
Our Approach
- For soap kits, we use phthalate-free fragrance oils for bright, consistent scents that hold well in soap bases.
- For bath kits (like fizzies and milk baths), we use natural fragrance oils whenever possible for a closer-to-nature experience.
- We avoid harsh additives, heavy perfumes, and any ingredients that could overwhelm kids’ senses or dry out skin.
Why Not Essential Oils?
Although essential oils are natural, they contain the full spectrum of a plant’s aromatic compounds, which can sometimes be too strong or irritating for children’s skin. They also vary in consistency and stability, making them harder to use safely in DIY kits. By choosing natural fragrance oils instead, we can deliver gentle, stable scents that give kids the fun sensory experience while keeping skin comfort in mind.
Why it matters
Fragrance can be a source of concern for parents, and for good reason. Our promise is that every scent in a Wunderkit is cosmetic-grade, kid-appropriate, and chosen for both safety and fun, so kids get the delight of tropical, coconut, vanilla or berry-bright scents, and parents get peace of mind.
What are SLS, sulfates, parabens, and phthalates, etc. anyway?
We're proud to say we've gone to great lengths researching ingredients to avoid in our kits. You've likely heard of these terms outside of Wunderkits, but what exactly are SLS/SLES (detergents), sulfates, PEG, parabens, and phthalates and why should you care that we avoid them?
Here's the scoop:
PEG (Polyethylene Glycol)
PEGs are petroleum-based compounds often used to make lotions feel smooth or help products mix together. The concern is that they can sometimes be contaminated with harmful byproducts during manufacturing, which is difficult to trace.
Phthalates
Phthalates are chemicals used to make plastics flexible and to help fragrances stick around longer. Studies link them to hormone disruption and environmental harm. We never use phthalates, instead, we only use natural fragrance oils and other fragrances that are always phthalate-free.
Sulfates (SLS/SLES)
Sulfates are foaming agents that create lots of bubbles in soaps and shampoos. The problem? They can be harsh on skin, strip away natural oils, and even cause irritation during handling. We avoid sulfates entirely so kids can mix safely, even if our fizz and foam look a little different from commercial products.
Parabens
Parabens are preservatives used to stop products from spoiling. The concern is they can mimic hormones in the body and disrupt balance, especially with long-term use.
