Benzophenone: Profile, Properties, and Safe Handling

What is Benzophenone?

Benzophenone belongs in the ketone family, known for a distinctive aromatic scent and solid form at room temperature. Colorless and crystal-like, benzophenone’s structure is built on two connected benzene rings and a central ketone group. That structure creates stability, helping block and absorb ultraviolet light. Sunscreen products often rely on it. The chemical formula, C₁₃H₁₀O, shows its carbon backbone with oxygen attached, while the molecular weight clocks in at about 182.22 grams per mole. Whether flakes, loose powder, chunky solid, or pressed pearls, benzophenone takes on various shapes, each reflecting differences in density, ease of handling, or flow needs, which matters for a chemist scooping and mixing it.

Physical Properties and Appearance

Benzophenone travels from laboratory shelf to industrial warehouse as pale-yellow or clean white flakes, powder, or crystalline chunks. Liquid forms come up only at higher temperatures, since it melts at around 47°C and boils above 305°C. In my own work, it arrived in tough glass jars: Flakes almost shiny, like the tip-off on a block of paraffin. The density stands at about 1.11 g/cm³. If you ever shove a spatula into benzophenone, you notice how those flakes break up with little resistance, much easier than a chunk of raw sulfur or stubborn sodium chloride. That lightweight powder sometimes floats in the air, so care is required to keep the space ventilated, avoiding unnecessary inhalation.

Chemical Properties

Benzophenone carries strength as both a photo-protector and a chemical intermediate. The molecule’s backbone holds up to heat and light, perfect for stabilizing plastics and stopping polymer degradation in sunlight. Chemical suppliers rate it as stable under standard conditions, not reactive with most household acids or bases. Still, strong oxidizing agents change its properties dramatically, pushing it to convert to benzoic acid or other compounds. In dry storage, away from moisture, it keeps its shape and power for years, which helps maintain quality across industries and research institutions.

Industrial Uses and Raw Material Role

Industrial workers reach for benzophenone in more than just cosmetics. Manufacturers add it to inks to cut down on yellowing from sunlight, giving print products a longer shelf life. In foods, some packaging leans on benzophenone for its UV shielding, provided it stays within safe boundaries established by regulatory agencies. From my experience watching production lines, benzophenone often enters as a raw material at the very start, gearing up for transformations into pharmaceuticals, photoinitiators, and plastic additives.

HS Code and Regulatory Classification

The international trading system classifies benzophenone under HS Code 2914.70, which covers ketones and quinones’ derivatives. Laboratories importing or exporting it need to tag it right for customs checks and safety compliance. Most suppliers follow standardized testing and labeling for hazardous materials, which ensures transparency from East Asia to North America.

Safety, Hazards, and Environmental Impact

Benzophenone’s usefulness brings responsibility. Safety sheets flag harmful effects if inhaled or absorbed through the skin, highlighting risks like allergic skin reactions, eye irritation, or, with enough exposure, kidney or liver trouble. Safe handling starts by keeping the workspace tidy, using gloves, eye shields, and local ventilation. If you spill it, dry powder vacuums or damp cloth pickup — never sweep — keep reactants from drifting into the air. Disposal always runs through regulated hazardous waste channels. Environmental concerns center around slow breakdown in soil and water environments, with ongoing research into the impact on aquatic wildlife. People working with this chemical, either in a manufacturing setting or a research bench like mine, need clear safety briefings and easy access to Material Safety Data Sheets (MSDS).

Storage, Transport, and Specifications

Shelf life depends on humidity and light control — benzophenone needs storage in sealed, clearly marked containers, away from incompatible chemicals. Some packaging uses inert atmosphere with nitrogen fill, especially for high-purity grades called for in electronics or specialty pharma work. Transport regulations require DOT-approved containers, often polyethylene, glass, or metal drums. Suppliers offer grades by purity: technical for industrial blending, and high-purity for research or pharmaceutical use. Each grade publishes a certificate of analysis outlining melting point, density, and assay percentage.

Solutions for Safer Use and Better Management

Protecting people and the environment starts with strong workplace training and real-time hazard monitoring. Air extraction units in production lines, frequent surface cleaning, and personal protective equipment make a huge difference — standards I saw enforced on my own lab floor. Product design shifts away from single-use to reusable packaging, recycling plans, and biodegradable alternatives carry promise for reducing benzophenone’s environmental load. Digital reporting and inventory systems help track shipments, flagging any unexpected changes in physical state or contamination. For those handling benzophenone from raw material to finished product, accountability means not just knowing the properties, but also making a culture of transparent communication and continuous improvement part of the job.