• Chemical Name: Sodium Bicarbonate
• Common Names: Baking Soda, Bicarb Soda, Bicarbonate of Soda, Bread Soda
• INCI Name: Sodium Bicarbonate
• Chemical Formula: NaHCO₃
• CAS Number: 144-55-8
• E Number: E500(ii)
• Molecular Weight: 84.01 g/mol
• Grade: Food Grade / Pharmaceutical Grade
• Appearance: Fine white crystalline powder
• Odour: Odourless
• Taste: Mildly salty, slightly alkaline
• pH (1% solution in water): Approximately 8.3 — mildly alkaline
• Solubility: Soluble in water; insoluble in ethanol
• Purity: ≥99% Sodium Bicarbonate
• Bulk Density: Approximately 0.85 g/cm³
• Particle Size: Fine milled — suitable for cosmetic and bath bomb applications
• Storage: Store in a sealed container in a cool, dry place away from moisture, acids, and heat. Keep away from citric acid in storage to prevent premature reaction
• Shelf Life: Indefinite when stored correctly in sealed, dry conditions; check quality if exposed to moisture

HOW IT WORKS — THE BATH BOMB FIZZ REACTION

The iconic bath bomb fizz is a simple acid-base reaction:

Sodium Bicarbonate (base) + Citric Acid (acid) + Water → Carbon Dioxide gas (CO₂) + Sodium Citrate + Water

The CO₂ gas released is what creates the bubbles and fizz. This reaction only occurs in the presence of water — which is why keeping your bath bomb mixture dry during making is essential to preserve the fizz until the bomb hits the bath.

The ratio of sodium bicarbonate to citric acid directly controls the intensity of fizz and the pH of the bathwater. The standard starting ratio for bath bombs is 2 parts sodium bicarbonate to 1 part citric acid (2:1). At this ratio all of the citric acid is neutralised, resulting in a slightly alkaline final pH in the bath which is gentle on skin. Reducing the ratio toward 1:1 creates a more neutral bathwater pH. Increasing the bicarbonate beyond 2:1 leaves excess unreacted bicarbonate which raises the bath pH further.

RECOMMENDED USAGE RATES

Bath Bombs (standard)

• Sodium Bicarbonate: 50–60% of total dry weight
• Citric Acid: 25–30% of total dry weight
• Standard 2:1 ratio (bicarb:citric acid) by weight

Bath Bomb — Typical 100g Single Bomb Recipe Starting Point

• Sodium Bicarbonate: 60g
• Citric Acid: 30g
• Cornstarch / Arrowroot Powder: 5g
• Salt / Epsom Salt: optional 5–10g
• Carrier Oil (Sweet Almond, Castor, etc.): 5–10ml
• Essential or Fragrance Oil: 1–3ml
• Colourant: as needed
• Witch Hazel / Isopropyl Alcohol: spritz to bind as needed

Bath Soaks and Bath Salts

• Sodium Bicarbonate: 10–30% of total dry blend
• Adds skin softening, pH buffering, and gentle effervescence when combined with citric acid

Natural Cleaning Powder (all-purpose)

• Sodium Bicarbonate: 50–70%
• Washing Soda (Sodium Carbonate): 20–30%
• Optional: Citric Acid 5–10%, Borax 5–10%

Laundry Powder

• Sodium Bicarbonate: 20–30% of total formulation
• Boosts cleaning, neutralises odours, softens water

Cosmetic Exfoliant (face and body scrubs)

• Sodium Bicarbonate: 5–20% of total formulation
• Use with caution on facial skin — fine grade only; avoid for sensitive or compromised skin

Deodorant Powder / Natural Deodorant Base

• Sodium Bicarbonate: 5–30% of total powder blend
• Note: high concentrations can cause skin irritation in some individuals — test at lower rates first

Cold Process Soap (soda ash prevention)

• Sodium Bicarbonate: not used in the soap recipe itself
• Spritz diluted sodium bicarbonate solution on top of freshly poured cold process soap to reduce soda ash formation during the gel phase

The essential base ingredient for bath bomb making — irreplaceable in the acid-base fizz reaction with citric acid

Food grade and pharmaceutical grade purity — safe for direct skin contact, cosmetic formulations, and food applications

Mildly alkaline pH of approximately 8.3 — gently buffers bathwater toward a skin-comfortable pH range

Naturally softens bathwater — leaves skin feeling silky and smooth after soaking

Non-toxic, biodegradable, and septic-safe — ideal for eco-conscious Australian households and green product lines

Effective natural deodoriser — neutralises acidic odour compounds rather than masking them

Gentle abrasive cleaning action — safe for use on most surfaces including stainless steel, ceramic, and glass

Versatile across cosmetic, cleaning, culinary, and bath product applications

Bulk quantities available — cost-effective for small businesses, cottage industry makers, and regular home users

Stores indefinitely in sealed, dry conditions — no expiry concern when stored correctly

Fast dispersion in water — fine milled grade dissolves quickly in bath bomb recipes and wet formulations

TYPICAL APPLICATIONS

• Bath bombs — primary fizzing base ingredient
• Bath soaks and bath salts
• Shower steamers
• Natural cleaning powders and pastes
• Laundry powders and boosters
• Dishwasher cleaning powders
• Kitchen and bathroom surface scrubs
• Natural deodorant powders and sticks
• Drain cleaning and maintenance
• Cosmetic exfoliant in face and body scrubs
• pH adjustment in cosmetic formulations
• Fridge and freezer odour elimination
• Pet odour neutralisation
• Baking and cooking (leavening agent)
• Cold process soap — soda ash prevention spray

Food grade — safe for intended cosmetic, cleaning, and culinary applications

Generally recognised as safe (GRAS) for food use — E number E500(ii)

Mild alkaline — pH of approximately 8.3 in solution; not corrosive or hazardous at cosmetic use concentrations

Avoid contact with eyes; if contact occurs rinse thoroughly with water

High concentrations in deodorant formulations may cause underarm irritation or rash in sensitive individuals — start at lower concentrations (5–10%) and patch test

Keep away from acids in storage — proximity to citric acid, vinegar, or other acids in humid conditions can trigger a slow premature reaction

Keep out of reach of children

Not for inhalation of dust in bulk — use dust mask when handling large quantities in powdered form

Store sealed away from moisture — exposure to humidity can cause clumping and partial activation

Biodegradable and environmentally safe — suitable for greywater and septic systems

What is the difference between sodium bicarbonate, baking soda, and bicarb soda?
They are all the same thing — three names for the identical compound, NaHCO₃. In Australia the most common everyday name is bicarb soda or bicarbonate of soda. In the United States the term baking soda is more common. Sodium bicarbonate is the chemical name. Our product is food grade, meaning it meets the purity standard required for culinary use and is also suitable for cosmetic formulation, bath bomb making, and natural cleaning applications.

What is the correct ratio of sodium bicarbonate to citric acid for bath bombs?
The standard starting ratio is 2 parts sodium bicarbonate to 1 part citric acid by weight — written as 2:1. This is the most widely used ratio in bath bomb making and produces a well-fizzing bomb with a slightly alkaline bathwater pH that is comfortable on skin. At this ratio all of the citric acid is neutralised by the bicarbonate. Some makers use a 3:2 ratio (e.g. 60g bicarb to 40g citric acid in a 100g bomb) for a slightly softer fizz and more neutral pH. Experiment to find the texture, fizz level, and skin feel that works for your recipe.

Why does my bath bomb mixture fizz prematurely when I'm making it?
Premature fizzing during bath bomb making is caused by moisture activating the acid-base reaction between sodium bicarbonate and citric acid before you want it to. Common causes include high humidity in your workspace, wet hands, adding too much liquid binder at once, or oil with water content. Work in a dry, air-conditioned space when possible, use 99% isopropyl alcohol or witch hazel as your binder (both have minimal water content), add liquids slowly and carefully, and work quickly once liquids are added.

Can I use this sodium bicarbonate for baking?
Yes — our Sodium Bicarbonate is food grade and pharmaceutical grade purity, making it fully suitable for culinary use as a leavening agent in baking. It is identical in purity and function to the sodium bicarbonate sold in supermarkets for baking, but available in larger bulk quantities at better value for households and small food businesses that use it regularly.

Is sodium bicarbonate the same as baking powder?
No. Baking powder is a mixture of sodium bicarbonate plus a dry acid (usually cream of tartar or sodium acid pyrophosphate) and a starch. It is a self-contained leavening system that activates with moisture alone. Sodium bicarbonate (baking soda) is the pure compound alone — it requires an acid in the recipe (buttermilk, vinegar, lemon juice, citric acid) to produce CO₂ and leaven. For bath bombs you want pure sodium bicarbonate — not baking powder, which contains additional ingredients that would interfere with the formulation.

Can I use sodium bicarbonate in cold process soap making?
Sodium bicarbonate is not typically used as a direct ingredient in cold process soap recipes — it does not participate in saponification. However it has one useful application in cold process soap: a diluted spray of sodium bicarbonate solution (approximately 1 teaspoon dissolved in 250ml of water) applied to the surface of freshly poured soap can help reduce soda ash formation during the cure phase by neutralising the surface before the ash can develop. Many experienced soap makers use this technique with good results.

Is bulk sodium bicarbonate available for wholesale or business use?
Yes — we stock Sodium Bicarbonate in bulk quantities suitable for small businesses, cottage industry bath product makers, cleaning product formulators, and high-volume household users. Contact us to discuss pallet orders and commercial quantities. Fast dispatch from our Melbourne warehouse to all states across Australia.

How should I store sodium bicarbonate to prevent clumping?
Store in an airtight sealed container in a cool, dry location away from moisture, steam, and acids. Sodium bicarbonate absorbs moisture from the air and will clump if exposed to humidity. Keep it physically separated from citric acid in storage — if stored together in a humid environment, the two can slowly react even without direct mixing. If your sodium bicarbonate has developed minor lumps from moisture exposure, it is still usable — break up the lumps and sieve before use in bath bomb recipes.

YOU MAY ALSO NEED

• Citric Acid — the essential partner ingredient for bath bomb fizz; always used alongside sodium bicarbonate
• Bath Bomb Supplies Collection — shop the full range of bath bomb making ingredients
• Bath Bomb Moulds — 6.5cm round plastic moulds for perfect sphere bath bombs
• Castor Oil (Hexane Free) — popular oil addition to bath bomb recipes for skin conditioning
• Essential Oils Collection — scent your bath bombs with pure essential oils
• Fragrance Oils — phthalate-free fragrance oils for bath bombs and soaking products
• Epsom Salt — blend with sodium bicarbonate for muscle relief bath soaks
• Colourants — Micas — cosmetic grade mica powders to colour your bath bombs
• Beginner Emulsified Sugar Scrubs Digital PDF — expand your DIY bath product range
• A Guide to Soapmaking Digital PDF — includes bath bomb recipes and ingredient guidance