Nappy Rash Worries? CastorBub Is Here For Your Baby’s Delicate Skin

September 29, 2025 Tracey Bailey

I know when my girls were babies, I didn't want to lather them up with harsh chemicals, but I also wanted something that actually worked to keep them comfortable, and not crying out from the sting of nappy rash. For 20 years at Biome, we've been strong supporters of Australian-made natural bottom balms, and now we have created our own special solution — meet CastorBub.

When nappy rash strikes, it can get bad fast. What starts as a little redness can quickly turn into sore, inflamed skin that leaves babies distressed through nappy changes and during the night. That’s why prevention is so important — keeping a protective barrier on the skin helps stop rash before it takes hold.

The worries parents have about baby creams

Chemical overload. A recent survey found that 90% of parents worry about toxic chemicals in baby products (Cosmetics Design Europe, 2024). And for good reason, many mainstream creams sneak in petroleum, silicones, parabens, and synthetic fragrance. Parents want something cleaner and safer.
Does it even work? Nappy rash is one of the top frustrations in baby care. Some creams only treat the rash after it appears, while others dry the skin out. Parents want prevention, a cream that forms a shield before irritation sets in.
Baby-soft skin = ultra sensitive. A newborn’s skin is up to five times thinner than an adult’s (Cosmetics Design Europe, 2024). That makes it extra permeable and extra prone to irritation from harsh formulas.
Messy textures. One thing parents mention often: sticky, chalky bottom balms that clump or won’t wipe off easily. Who has time to wrestle with that at 2am?

Why CastorBub barrier cream is different

Biome’s CastorGuard has already earned glowing 5-star reviews for soothing and hydrating dry skin. And now, CastorBub takes this trusted formula into the world of baby care—introducing zinc oxide for gentle protection against nappy rash.

Castor oil (hexane-free) – the star ingredient, known for its silky texture and moisture-locking ability.
Non-nano zinc oxide – with a slightly powdery feel, creates a protective barrier to help prevent nappy rash by shielding skin from moisture, urine, and friction.
Apricot kernel oil & shea butter – soothe and comfort delicate skin.
Natural waxes (carnauba & candelilla) – keep the balm smooth, spreadable, and never sticky.
Vitamin E

How CastorBub compares to other creams

Parents often assume all barrier creams are much the same—but the ingredient list tells a very different story. Here’s how CastorBub stacks up against three top name baby bottom creams found in Australia (full ingredients in the footer if you're interested).

Brand	Key Ingredients	Synthetic / Petroleum Additives?
QV Baby Barrier Cream	Aqua, Zinc Oxide, Dimethicone, Paraffinum Liquidum, Ceteareth-25, Methylparaben	Yes – paraffin, silicones, parabens, synthetic emulsifiers
Sudocrem	Zinc Oxide, Liquid Paraffin, Paraffin Wax, Microcrystalline Wax, Propylene Glycol, Synthetic Beeswax	Yes – multiple petroleum derivatives, synthetic waxes, glycols
Bepanthen	Wool Fat (Lanolin), Liquid Paraffin, Soft White Paraffin, Cetyl/Stearyl Alcohol	Yes – mineral oils, paraffin, alcohols
CastorBub	Hexane-free Castor Oil, Hydrogenated Castor Oil, Carnauba & Candelilla Wax, Apricot Kernel Oil, Shea Butter, Zinc Oxide, Natural Vitamin E	No – 100% natural oils, butter, waxes, and zinc oxide

While mainstream brands rely heavily on petroleum-based fillers and synthetic stabilisers, CastorBub bottom balm is made only with natural oils, waxes, and non nano zinc oxide, giving parents a safer, gentler option for their baby’s delicate skin.

More than just bottoms

Yes, CastorBub is made for babies, but parents and carers will find themselves using it in all sorts of ways. It’s a gentle skin barrier balm for bottoms, chubby cheeks, skin folds, dry patches.

In fact, it's even handy for the whole family to borrow for chafing and irritation.

Full ingredients of baby barrier creams

QV Baby Barrier Cream: Aqua (Water), Zinc Oxide, Dimethicone, Paraffinum Liquidum, Glycerin, Cetearyl Alcohol, Ceteareth-25, Panthenol, Methylparaben, Xanthan Gum

Sudocream Healing Cream: Zinc Oxide, Benzyl Alcohol, Benzyl Benzoate, Benzyl Cinnamate, Lanolin, Purified Water, Liquid Paraffin, Paraffin Wax, Microcrystalline Wax, Synthetic Beeswax, Sorbitan Sesquiolate, Propylene Glycol, Antioxidants, Sodium Benzoate, Linalyl Acetate, Lavender Oil

Bepanthen: Purified Water, Wool Fat (Anhydrous Lanolin), Liquid Paraffin, Soft White Paraffin, Dexpanthenol (Provitamin B5), Almond Oil, White Beeswax, Cetyl Alcohol, Stearyl Alcohol, Protegin XN.

CastorBub: Hexane free Castor Seed Oil, Hydrogenated Castor Oil (from castor beans), Carnauba Wax, *Apricot Kernel Oil, *Shea Butter, Candelilla Wax, **Zinc Oxide, Tocopherol (Natural Vitamin E)