Bumetrizole
[CAS# 3896-11-5]

Identification

• Classification: Catalysts and additives >> UV absorber
• Name: Bumetrizole
• Synonyms: 2-(3-tert-Butyl-2-hydroxy-5-methylphenyl)-5-chloro-2H-benzotriazole; 2-(5-Chloro-2H-benzotriazol-2-yl)-6-(1,1-dimethylethyl)-4-methylphenol
• Molecular Formula: C₁₇H₁₈ClN₃O
• Molecular Weight: 315.80
• CAS Registry Number: 3896-11-5
• EC Number: 223-445-4
• SMILES: CC1=CC(=C(C(=C1)N2N=C3C=CC(=CC3=N2)Cl)O)C(C)(C)C

Properties

• Density: 1.3±0.1 g/cm³, Calc.^*
• Melting point: 144-147 °C (Expl.)
• Index of Refraction: 1.628, Calc.^*
• Boiling Point: 460.4±55.0 °C (760 mmHg), Calc.^*
• Flash Point: 232.3±31.5 °C, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H413
• Safety Statements: P273-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	4	H332
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Acute toxicity	Acute Tox.	4	H312
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Eye irritation	Eye Irrit.	2A	H319

Discovery and Applications

Bumetrizole is an organic compound classified as a benzotriazole derivative, primarily known for its application as a UV stabilizer and absorber in various industries. It is part of a group of chemical compounds that have demonstrated excellent ability to protect materials from the harmful effects of ultraviolet (UV) radiation, particularly in polymer and plastic applications. This compound is often used to enhance the durability and longevity of products exposed to sunlight, thereby extending their functional life.

The discovery of bumetrizole can be attributed to ongoing research into UV-absorbing chemicals in the late 20th century. The need for materials that could withstand prolonged exposure to UV radiation, which accelerates degradation and degradation of physical properties, led to the development of several UV stabilizers. Among these, bumetrizole emerged as one of the more effective candidates due to its strong absorbance properties in the UV-B and UV-C ranges. Its ability to absorb UV light and convert it into non-damaging energy makes it a valuable additive for preventing the photodegradation of sensitive materials.

The most significant application of bumetrizole is in the plastics industry. It is commonly used in the production of films, coatings, and other plastic materials that are exposed to sunlight. Bumetrizole prevents the breakdown of polymers by absorbing UV radiation, thus preserving their mechanical and optical properties over extended periods. For example, in the automotive industry, bumetrizole is used in the production of vehicle parts such as bumpers, headlights, and dashboards, which are continuously exposed to sunlight. By preventing the materials from becoming brittle or discolored, bumetrizole helps maintain their aesthetic and functional properties.

Another important application of bumetrizole is in the protection of textiles, particularly outdoor fabrics and clothing. As outdoor products such as tents, umbrellas, and outdoor furniture are often exposed to UV radiation, bumetrizole is included in fabric treatments to enhance their resistance to UV damage. It is also used in agricultural films to protect crops from excessive UV exposure, thus helping to prevent damage and improve yields.

Bumetrizole is also utilized in the formulation of personal care products, such as sunscreens and cosmetics, where it acts as a UV filter. It absorbs UV radiation and prevents it from penetrating the skin, thus protecting against sunburns and photoaging. The compound is included in many sunscreen formulations due to its ability to provide broad-spectrum protection against both UVA and UVB radiation.

In conclusion, bumetrizole plays an essential role in various applications requiring UV protection. From plastics and textiles to personal care products, this chemical offers a reliable and effective solution to combat the degradation caused by UV exposure. Its discovery and subsequent use have proven invaluable in enhancing the durability and performance of products in a wide range of industries.

References

2023. Environmental Risk Assessment of Plastics and Its Additives. In: Handbook of Green and Sustainable Nanotechnology. Springer.
DOI: 10.1007/978-3-031-16101-8_33

2018. A new multistep purification method for simultaneously determining organic ultraviolet absorbents in fish tissue. Environmental Monitoring and Assessment, 190(12).
DOI: 10.1007/s10661-018-7139-8

1994. Contact sensitivity of and cross-sensitivity between 2-(2′-hydroxy-5′-methylphenyl)benzotriazole (Tinuvin® P) and 2-(2′-hydroxy-3′-tert-butyl-5′-methylphenyl)-5-chlorobenzotriazole (Tinuvin® 326) evaluated by lymph node cell proliferation and ear swelling response in mice. Toxicology Letters, 71(2).
DOI: 10.1016/0378-4274(94)90175-9