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Chemical Name: 3,4-Dihydroxybenzaldehyde SYNONYMS: Protocatechualdehyde CAS Number: 139-85-5 Chemical Formula: C7H6O3 Appearance: Pale yellow to light brown crystalline solid Usages: Specialty chemical in organic synthesis, intermediate in pharmaceuticals, dye manufacture Odor: Distinct aromatic, sometimes sharp scent Unique Features: This compound pops up in a lot of lab syntheses because of its reactivity in building more complex molecules. If you’ve spent time at a lab bench, you’ll recognize its spot among aromatic aldehydes.
GHS Classification: Eye irritation, mild skin irritation, potentially hazardous if ingested in quantity Signal Word: Warning Hazard Statements: May cause eye irritation, may cause respiratory irritation, can trigger skin discomfort Precautionary Statements: Avoid breathing dust, fumes, or vapors. Wear gloves and goggles. Wash hands thoroughly. Routes of Exposure: Inhalation, skin contact, eye contact, ingestion Remark: Simple molecules like this sometimes get underestimated, as people tend to relax their guard compared to bigger-name hazardous chemicals.
Main Component: 3,4-Dihydroxybenzaldehyde, purity generally exceeds 98% in commercial lots Impurities: Trace moisture, residual solvents from synthesis Trade Additives: None typically present — most lab stocks are single-component so you’re handling the real deal, not a mix.
Inhalation: Move to fresh air, get comfortable, monitor for headaches or dizziness; seek medical help if symptoms stick around Skin Contact: Wash with soap and running water, remove contaminated clothing. Skin can show redness or irritation, so don’t treat it as routine. Eye Contact: Flush with clean water for 15 minutes, keep eyelids open, seek medical attention if discomfort persists Ingestion: Rinse mouth, drink water, do not force vomiting; see a doctor as soon as possible Advice for Doctors: Treat symptomatically — this compound’s effects typically come down to irritation, not systemic toxicity
Suitable Extinguishing Media: Carbon dioxide, dry chemical, alcohol-resistant foam — water spray works but watch runoff Specific Hazards: Can release carbon oxides if burning, so ventilation counts for a lot Protection for Firefighters: Standard protective gear and self-contained breathing apparatus; small powders can kick up in a fire, so don’t let your guard down Special Notes: Solid samples can smolder or generate smoke if burning, adding risk to nearby plastics or paperwork
Personal Precautions: Avoid skin and eye contact, ventilate the area, put on gloves and eye protection Environmental Precautions: Prevent spills from getting to drains or water systems — best bet is to collect and seal waste for proper disposal Cleanup Methods: Sweep up material, avoid generating dust, wipe down with damp cloth, double-bag waste Sensitivity: Even for small spills in labs or pilot plants, wear simple protection and keep the area neat — this keeps minor accidents from growing into larger headaches
Handling: Avoid breathing dust, wear gloves, eye protection, and handle in well-ventilated spaces Storage: Keep container tightly closed, store cool and dry, shield from direct sunlight, avoid heat, segregate from oxidizers Long-Term Stability: Careless storage can lead to gradual yellowing or breakdown, so a tight cap and a dry, dark spot go far in maintaining quality Personal Note: A shelf cluttered with poorly sealed vials often ends in wasted product and hard-to-clean messes — spend a few seconds to cap things properly
Engineering Controls: Work with fume extraction where possible, keep the bench clean Personal Protection: Chemical-resistant gloves, safety goggles, lab coat, closed-toe shoes — a PPE routine makes chemical handling less risky and more professional Exposure Limits: No established occupational limits for this chemical, but use conservative standards as you would with similar aromatic aldehydes Personal Hygiene: Wash hands after use, no eating or drinking near workspaces, keep drinks out of the lab Community Experience: People who start with casual handling often end up taking these habits home — take the extra care at work, and you’ll have fewer accidental exposures to explain later
Appearance: Light yellow to beige powder or crystalline solid Odor: Mild, aromatic scent, a bit sharper than vanillin Molecular Weight: 138.12 g/mol Melting Point: About 148–151°C Solubility: Reasonably soluble in organic solvents like ethanol, DMSO, acetone, and somewhat in water Boiling Point: Not typically measured due to decomposition Vapor Pressure: Very low at room temperature Other Properties: Light-sensitive, so color may fade or deepen with exposure over time Personal Note: If you work through a sweltering summer or in patchy air conditioning, stability suffers and you notice powder clumping and color changes
Chemical Stability: Stable under recommended storage — cool, dry, sealed Reactivity: Reacts with strong oxidizing agents, can polymerize or degrade if left open and moist Conditions to Avoid: Excess moisture, high temperatures, exposure to light Incompatible Materials: Strong bases, oxidizers, some reducing agents Decomposition Products: Fumes from burning or decomposition may include carbon monoxide and carbon dioxide Routine Observations: Even a little moisture can lead to caking or fouling the edges of bottles, so dry storage pays off in easy handling
Acute Toxicity: Low oral and dermal toxicity has been reported, but not a compound to swallow or rub in — best to avoid deliberate exposure Irritation: May cause skin or eye irritation, respiratory tract discomfort in dusty or misty conditions Chronic Effects: No long-term studies in humans but analogs can sensitize skin with repeated sloppy exposure Mutagenicity / Carcinogenicity: No direct evidence suggests mutagenic or carcinogenic risks at normal laboratory exposures Additional Thoughts: I’ve observed novices dismiss small molecule organics as harmless, but extended contact with eyes or skin almost always ends with regret; precaution works better than quick fixes
Aquatic Toxicity: Not considered highly toxic to aquatic life but data remains limited Persistence and Degradability: Readily biodegradable under aerobic conditions — can break down with sunlight and oxygen Bioaccumulation: Unlikely to build up in organisms because breakdown occurs faster than absorption Environmental Caution: Pouring into drains or soil builds up risk for local disruption. Even if the literature says low toxicity, accumulation in lab sink traps or wild runoff means small spills count over time.
Waste Disposal Methods: Gather contaminated residues and solutions, label properly, send to specialized chemical disposal units Container Cleaning: Rinse thoroughly or triple-wash before recycling or disposal, then manage washes as hazardous waste Regulatory Aspects: Disposal practices should follow local, state, and national guidelines — environmental authorities check labs for compliance, and shortcomings can lead to steep fines Personal Reflection: It’s easy to ignore disposal rules in low-traffic labs, but enforcement can surprise the unprepared — systematic waste management saves headaches
UN Number: Not classified as a hazardous material for ground, air, or sea transport Hazards During Transport: Spills during shipping usually result in minor cleanup, but powder form can get airborne and spread Packaging Requirements: Sealed containers, secondary containment (plastic bag or foam), clear labeling Observation: Many incidents occur not from the compound itself but from poor sealing — I’ve seen whole shipments turn into a fine mess because of lazy repacking at shipping docks
Labeling Requirements: GHS hazard pictograms (exclamation mark), signal word “Warning” Regulation by Country: Not on key international hazard lists (such as US TSCA, EU REACH) in significant quantity restrictions Workplace Rules: Whichever workplace safety policies fit organic chemicals apply — eye protection, closed containers, waste audits Community Standards: Standard laboratory rules work well, but periodic refresher training closes knowledge gaps for newer staff. Ignoring these rules undermines both lab safety and trust for everyone working around organics like this.
