Sodium benzoate powder is a water-soluble preservative used to stop the growth of yeasts, moulds and some bacteria in water-based products. If you make lotions, shampoos, liquid soaps, room sprays or cleaning liquids at home or for a small business, it helps your batches stay fresh and safe to use for longer. It is the sodium salt of benzoic acid, made by neutralising benzoic acid with sodium hydroxide, and appears as a fine white powder.
What sodium benzoate is used for
This ingredient occurs naturally in small amounts in fruits like apples, prunes and cranberries, but the version sold for manufacturing is produced industrially to a consistent purity. Because it dissolves easily in water and works well at a mildly acidic pH, it is a common choice across many product types.
- Skin care: creams, lotions, serums and gels that contain water.
- Hair care: shampoos, conditioners and hair masks.
- Bath and body: liquid soaps, body washes and bath products.
- Household products: surface cleaners and liquid detergents.
- Food and pharmaceutical grades: used industrially, though the technical-grade powder here is intended for external and manufacturing use.
It is also used to protect a formula's condition, helping guard against spoilage and keeping the product effective over its intended shelf life.
How to use it in a formula
Sodium benzoate works best in acidic conditions. The active preserving form (benzoic acid) is only available when the pH of your finished product is below about 5.5, and it becomes more effective the lower you go. Above that, it loses much of its punch, so always check and adjust your pH.
- Dissolve the powder fully in the water phase of your formula. It is soluble in water and mixes in easily.
- Use a typical rate of around 0.5% to 1% of the total weight of your product, unless your specific recipe advises otherwise.
- Adjust the final pH of your product to below 5.5 (many use 4 to 5) so the preservative can actually do its job.
- It is often paired with potassium sorbate for broader coverage against moulds and yeasts.
Weigh accurately with a small kitchen or jewellery scale. Guessing amounts either leaves a product under-preserved or wastes material.
Safety and handling
This is a technical-grade chemical, so treat it with care even though it is widely used.
- It is meant for external and manufacturing use. Do not eat the powder.
- Avoid direct contact with your eyes, and wash your hands after handling.
- Work in a well-ventilated space and avoid breathing in the fine dust.
- Keep it well away from children and pets.
- Combining it with high levels of vitamin C (ascorbic acid) is best avoided, as the two can react. If in doubt, keep to established recipes.
- Always do a small patch test on any new skin product you formulate before regular use.
Buying and storage tips
Azlok stocks Sodium Benzoate Powder in packs from 100 g right up to 20 kg, so you can buy a small quantity to trial a recipe or a bulk pack for regular production. The 100 g pack starts at ₹149, which suits hobby makers testing formulas.
- Look for a fine white powder with around 99% purity, as listed for this product.
- Store in an airtight container, in a cool, dry place away from direct sunlight and moisture.
- Kept properly, it has a shelf life of about 24 months.
- Ask for the COA and MSDS if you are formulating products for sale, so you have documentation on hand.
FAQ
What is sodium benzoate powder used for?
It is mainly used as a preservative in water-based cosmetics, personal care items and household cleaners, protecting them against mould, yeast and some bacteria so they last longer.
How much sodium benzoate should I add to my formula?
A common range is 0.5% to 1% of the total weight of the product. It only works well when the finished product's pH is below about 5.5, so adjust and check your pH.
Is sodium benzoate safe to use on skin?
Used at recommended low levels in leave-on and rinse-off products at the right pH, it is a well-established cosmetic preservative. This technical-grade powder is for external and manufacturing use only, not for eating. Patch-test finished products and keep the raw powder away from eyes and children.
Can I use sodium benzoate alone as a preservative?
It is often combined with potassium sorbate for broader protection, since sodium benzoate is more effective against moulds and yeasts than bacteria. Many makers use the two together in acidic formulas.
How should I store sodium benzoate powder?
Keep it in an airtight container in a cool, dry place away from sunlight and humidity. Stored this way it stays usable for around 24 months.