Sodium 4-Hydroxybenzene Sulfoate (Dihydrate), known to chemists for its distinctive aromatic structure, comes from a line of sulfonic acid derivatives. The core benzene ring features both a sulfonate and a hydroxy group, which really shifts the way the molecule interacts with water, organic solvents, and other chemicals. This compound shows up regularly in dyes, pharmaceutical synthesis, and certain laboratory reagents, often thanks to its water solubility and stable reactivity when handled with care. You pick up a bag of this, and you’re looking at solid white to off-white crystals or sometimes flakes—depends a bit on the source or the drying process. The substance has a tactile density you might recognize if you’ve handled other hydrated organic salts, typically measuring in at about 1.6 to 1.7 g/cm³. These flakes crunch and dissolve well in water, helping reactions or formulations where controlled sulfonate release matters.
You can rely on this chemical to consistently deliver as a solid, but manufacturers sometimes offer it as a fine powder, crystalline flakes, or even as small pearls, depending on process preferences. No matter the physical form, you’re looking at a molecular formula of C6H5NaO5S·2H2O. That brings the molecular weight to around 248.18 g/mol, meaning you can easily calculate dosages for lab or industrial use. This molecule stands out with a strong acidic sulfonate group, balanced by the sodium ion, plus two water molecules of crystallization—these physically lock in stability and make it easier to handle in moist or humid environments without much clumping. It’s fully soluble in water, which simplifies mixing and disposal, but you want to store it in a cool, dry place since excess moisture can sometimes cause caking or slow its dissolution. The crystal habit—a bit like coarse table salt—makes scooping, weighing, and dissolving straightforward even with bulk quantities.
Looking at the structure, Sodium 4-Hydroxybenzene Sulfoate (Dihydrate) shows a para relationship between the hydroxy and sulfonate groups. In practice, this gives the molecule a well-balanced dissociation in aqueous solutions, supporting high ionic mobility. The aromatic ring holds structural rigidity; meanwhile, the hydroxyl and sulfonate boost both reactivity with electrophiles and overall hydrophilicity. Safe handling really comes into play here—its chemical reactivity makes it a straightforward choice as a raw material in specific dye and intermediate manufacturing processes. Aqueous solutions run clear, and the lack of strong odor means routine lab handling doesn’t demand excessive ventilation, though dust control still matters for respiratory safety.
Industry standards for Sodium 4-Hydroxybenzene Sulfoate (Dihydrate) typically require a minimum assay of 98% on a dry basis, with low heavy metal content (often less than 10 ppm lead) and controlled pH in solution (around 6–8 for a 10% aqueous solution). You’ll see bulk packaging with a range of 25 kg bags or drums—sometimes lined to minimize water uptake. The HS Code for global trade most often comes down as 2908.19, placing it squarely in organic sulfonic acid sodium salts. Granulometry can matter in large reactors or with automated feeders; flaky or powder forms ease dosing. Quality assurance teams lean on infra-red (IR) and nuclear magnetic resonance (NMR) analysis for traceability, guaranteeing you get the right aromatic structure and hydration status before any process kicks off.
You’ll find real-world value for this compound in three main spaces: dyes and colorants (helping fix color in textile fibers), as an intermediate for making specialty aromatic compounds or certain pharmaceuticals, and as a sulfonating agent in chemistry labs. The hydrated form provides optimal flow for volume handling, and the excellent water solubility means it goes straight into aqueous solutions without waiting for long dissolution periods. In pharma circles, this compound’s reactivity aids in the synthesis of more complex sulfonated molecules; sometimes it plays a role in surfactant development or polymer production, where precise sulfonate content is needed. The food and agricultural industries tend not to use it directly, but knowledge of its behavior still spills over into water treatment or technical chemical formulations.
Safety matters for both workers and downstream users. Sodium 4-Hydroxybenzene Sulfoate (Dihydrate) gets classified as non-flammable, but the strong sulfonate and aromatic system mean you don’t want prolonged skin or eye contact. Standard glove and eye protection make sense during use. While the oral toxicity sits at a moderate level, chronic exposure hasn’t shown broad systemic harm, so ordinary industrial hygiene suffices. It’s not volatile, which simplifies storage—no tricky vapor scrubbing or special venting needed, unlike strong acids or bases. You don’t typically run into environmental risks unless large amounts reach waterways, in which case the enhanced biodegradability of aromatic sulfonates helps, but company EH&S teams still plan for containment and treatment steps. Emergency treatment often involves thoroughly flushing spills with water and neutralizing with basic agents, then packaging waste for approved chemical disposal. While the risk of acute hazard is low, dust generation remains a nuisance risk—effective dust extraction and regular surface cleaning go a long way toward keeping facilities safe.
Material storage rarely gives headaches with Sodium 4-Hydroxybenzene Sulfoate (Dihydrate) as long as the warehouse stays dry and temperature-stable. Double-bagging in moisture-barrier film cuts back on caking or accidental hydration, and well-sealed drums keep out rodents and minimize accidental spills. Facilities switch between bulk and smaller container sizes based on consumption rate and automation level, but anyone working with this chemical quickly learns to avoid leaving containers open to ambient air, since the hydrated form can pick up extra water or lose water with extended exposure. Inventory cycles depend on usage, yet this material stores well over six months if kept sealed and protected from temperature swings.
Most of the ongoing improvement in handling Sodium 4-Hydroxybenzene Sulfoate (Dihydrate) falls into two camps: automated bulk handling and green chemistry initiatives. Plant managers increasingly turn to closed transfer systems, reducing dust and direct human exposure—this keeps both efficiency and safety standards strong. As downstream users push for less environmental impact, suppliers look toward cleaner synthetic routes, expanded life-cycle tracking, and improved byproduct management. Lab-scale users benefit from small-batch suppliers offering pre-weighed packets that cut waste. Further research into recycling of sulfonated waste streams and decreased reliance on hazardous chemical precursors takes on growing importance. The chemical industry sits at the center of shifting regulation for aromatic and sulfonate substances, so transparent communication of ingredient origin, specification, and safety procedure forms the backbone of any modern supplier relationship. Suppliers committed to full traceability and scientific rigor meet the rising expectations set by global compliance and quality assurance initiatives, all while enabling real-world applications in a safer and more sustainable way.
