Product Overview
Sodium Bisulfite 40% ACS Grade is a ready-to-use aqueous reducing agent built for work that demands traceable purity. At 40% active concentration, the solution arrives as a clear, colorless to light-yellow liquid with a slight sulfur dioxide odor — dense enough (1.32–1.35 g/cm³) that you feel the weight when you pour it. ACS-grade designation means the material meets American Chemical Society reagent specifications, so every lot is suitable for quantitative analytical work, not just plant-floor duty.
we distribute this product in our Taylor, TX warehouse and ship it daily in DOT-compliant hazmat packaging. Whether you run a municipal water plant pulling residual chlorine, a QC lab running titrations, or a production floor synthesizing intermediates, this is the concentration and grade that lets you dose accurately without diluting from a more concentrated stock.
Why This Concentration
A 40% solution sits at the practical ceiling for sodium bisulfite in water. Push much higher and the salt begins to crystallize at cooler ambient temperatures, creating handling headaches in feed lines and metering pumps. At 40%, you get maximum active strength per gallon while the solution stays stable and pumpable across a normal warehouse and plant temperature range.
The ACS grade distinction matters when your results face scrutiny. Plant-floor dechlorination or pH adjustment can often run on a technical-grade product — if your process doesn't require reagent-level purity, Sodium Bisulfite 40% in technical grade will do the job at lower cost. Choose ACS when the work is analytical, when you need lot-traceable purity for validated methods, or when your SOP calls out a reagent-grade bisulfite explicitly.
Chemical Profile
Sodium bisulfite (CAS 7631-90-5, molecular formula HNaO₃S, molecular weight 104.06 g/mol) ships as a clear, colorless to light-yellow liquid. The solution is fully miscible with water and carries a density of 1.32–1.35 g/cm³ at 20 °C — noticeably heavier than water, which matters for volumetric dosing calculations. Expect a slight sulfur dioxide odor when you open the container; the odor intensifies if the solution contacts acids, which liberates SO₂ gas (per the product's GHS classification). This is a liquid form product, ready to meter or pour without dissolution steps.
Industrial Applications
Water Treatment & Dechlorination — Sodium bisulfite is the workhorse reducing agent for quenching residual chlorine in municipal discharge, industrial cooling loops, and reverse-osmosis pretreeatment systems. It reacts rapidly with free and combined chlorine, converting it to chloride. Operators dose it inline, typically through a chemical metering pump, and verify residual with a DPD test downstream.
Analytical Reagent — In the lab, ACS-grade sodium bisulfite serves as a titrant or reductant in redox analyses. Its known purity lets analysts calculate stoichiometry against the reagent-grade assay value without introducing uncertainty from impurities.
Chemical Synthesis — Bisulfite additions across carbonyl compounds (the bisulfite addition reaction) are a standard step in organic synthesis for isolating aldehydes and certain ketones. The 40% solution feeds directly into reaction vessels without a dissolution step.
Photographic Processing — Sodium bisulfite acts as a preservative in photographic developer formulations, scavenging dissolved oxygen that would otherwise degrade the developing agents.
Food-Industry Processing — Sodium bisulfite functions as an oxygen scavenger and preservative in certain food-processing operations, preventing enzymatic browning and inhibiting microbial activity during production.
Handling & Storage
This product carries a Danger signal word (per the product's GHS classification). The hazard statements you need to know:
- H302 — Harmful if swallowed
- H318 — Causes serious eye damage
- EUH031 — Contact with acids liberates toxic gas
That last statement is the one operators overlook. If bisulfite contacts strong mineral acids — hydrochloric, sulfuric, even acidic cleaning chemicals in the same secondary containment — it releases sulfur dioxide gas. Keep bisulfite segregated from acids and strong oxidizers in storage.
Store in tightly closed HDPE or compatible containers in a cool, dry, well-ventilated area. Prolonged air exposure degrades the bisulfite concentration through oxidation to sulfate, so reseal containers promptly. Wear chemical splash goggles (not safety glasses — the H318 eye-damage statement demands sealed eye protection), chemical-resistant gloves, and use in a ventilated space or with respiratory protection if SO₂ odor is noticeable.
Hazmat & Shipping
Sodium Bisulfite 40% is a regulated hazardous material for transport. Every shipment leaves our facility with compliant markings, labels, and documentation:
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UN Number: UN2693 (per 49 CFR 172.101)
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Hazard Class: 8 — Corrosive (per 49 CFR 172.101)
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Packing Group: III (per 49 CFR 172.101)
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Proper Shipping Name: Bisulfites, aqueous solutions, n.o.s. (Sodium bisulfite) (per 49 CFR 172.101)
We handle the placarding, packaging, and carrier coordination so your receiving dock gets a compliant shipment with the correct shipping papers.
Documentation
A Safety Data Sheet ships with every order and is available in English, Spanish, French, and Japanese. A lot-specific Certificate of Analysis is available on request, documenting the assay and impurity profile for the specific lot you receive — critical for labs running validated methods under ACS-grade specifications.
Why Buy from Alliance Chemical
We are hazmat operators, not just order-takers. Sodium Bisulfite 40% ACS Grade ships daily from our warehouse in Taylor, TX in DOT-compliant packaging selected for the container size — from quarts boxed with absorbent to 330-gallon totes palletized and placarded. Our shipping and handling guidance is reviewed by Andre Taki, DOT Hazmat Specialist, so the package that arrives at your dock meets 49 CFR requirements from label to paperwork. we distribute it, we pack it, we ship it — and we answer the phone when you have a question about compatibility or dosing hardware.
