Biome CastorBub™

For all ages

• Baby bottoms at nappy change
• Cheeks prone to dryness or wind
• Skin folds that need comfort and protection
• Dry patches on hands, elbows, or heels for kids and adults

Features & benefits

• Barrier protection: Zinc oxide forms a physical layer on the skin to help prevent nappy rash by shielding against moisture and friction.
• Moisturising & soothing: Castor oil and shea butter deeply condition and soften skin, helping to keep it supple and comfortable.  A big part of nappy rash agony is the baby’s discomfort–crying at nappy changes or when urine hits the rash.  CastorGuard creates a soothing sensation upon contact.
• Gentle on delicate skin: Formulated with simple, natural ingredients that are safe for newborns and sensitive skin.
• No nasties: Free from petroleum, synthetic fragrances, parabens, and artificial additives.
• Australian made: Crafted in small batches with care, supporting local quality and sustainability.

About the ingredients

Castor oil (hexane-free): The hero ingredient. Rich, smooth, and highly moisturising. Helps lock in hydration while supporting a protective barrier.

Zinc oxide (non nano): A mineral powder that creates a breathable shield, helping protect against nappy rash and irritation from wetness.  Zinc oxide works because it protects, dries, soothes, and defends all at once. It prevents worsening and creates the conditions for the skin to heal naturally.

Apricot kernel oil: Lightweight and easily absorbed, nourishing without greasiness.

Shea butter: Deeply conditioning, adds soothing comfort to dry or chafed areas.

Carnauba & candelilla waxes: Provide a stable, protective texture while remaining vegan-friendly.

FAQ: Baby Nappy Rash Cream & Barrier Balms

1. How does a barrier cream help prevent nappy rash?
Barrier creams work by creating a thin, protective layer over your baby’s skin. This shield helps keep moisture, urine, and irritants from sitting directly on the skin, which reduces friction and prevents redness from developing into a rash. A good barrier cream also locks in natural moisture to support healthy skin recovery.

2. How do I apply nappy rash cream correctly?
Gently clean and pat your baby’s bottom dry before applying. Use a thin, even layer of cream with clean hands at each nappy change, especially before longer sleeps. Focus on the creases and folds where moisture can get trapped, but avoid applying too thick a layer, as the skin still needs to breathe.

3. Can I use nappy rash cream on other dry or irritated areas?
Yes, many parents also use nappy rash cream on other spots prone to dryness or irritation. It can help soothe chapped cheeks, dribble rash under the chin, or dry patches on knees and elbows. Always check the ingredients first, and do a small patch test on sensitive skin.

4. What is the safest bottom balm?
The safest choice is a natural bottom balm made without petroleum, parabens, synthetic fragrances and preservatives. Look for formulations with zinc oxide for protection, plus soothing plant oils and butters. These natural ingredients are gentle enough for newborn skin, while still providing an effective barrier against moisture. 

5. Is CastorBub vegan and cruelty-free?

Yes!  We personally make CastorBub bottom balm in the Biome lab in Brisbane.  Many bottom balms contain beeswax and lanolin from sheep's wool.  CastorBub is vegan, the ingredients and the balm are not tested on animals.

What are the synthetic additives commonly found in conventional barrier creams?

Many mainstream barrier creams rely on synthetic additives to create texture, extend shelf life, or reduce manufacturing costs. While effective at forming a protective layer, these ingredients are often a concern for parents who want to avoid exposing delicate baby skin to unnecessary chemicals.  Some of the ingredients surprisingly found in popular baby nappy rash creams:

• Petroleum – Paraffinum Liquidum (mineral oil), Liquid Paraffin, Paraffin Wax, Microcrystalline Wax – inexpensive occlusives that form a barrier but offer no natural nourishment and are not biodegradable.
• Silicones – Dimethicone – synthetic polymers that coat the skin for smoothness, but do not feed or support skin health.
• Synthetic waxes – Synthetic Beeswax – lab-made substitutes 
• Petrochemical glycols – Ceteareth-25 and Propylene Glycol
• Preservatives – Methylparaben, Sodium Benzoate, Benzyl Alcohol – extend shelf life but are often avoided by parents concerned about sensitivity and potential hormone disruption.
• Fragrance-related compounds – Benzyl Benzoate, Benzyl Cinnamate, Linalyl Acetate – provide scent but are common irritants for sensitive skin.

Don't miss checking out our original CastorGuard with 140+ 5 star reviews.  CastorGuard is nature's Vaseline alternative - a multi-purpose petroleum-free balm made with castor oil. Users report it works for lip balm for dry lips, cracked heels, chafing, dry skin, dermatitis, puffy eyes, scratches, and more.

SHIPPING

Biome ships to Australia and the rest of the world > Full details here.   

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) *Cert.Organic ** Non nano, uncoated

50g in glass jar.