Metro

Metol is a chemical compound commonly used as a developing agent in photographic processing. It is known for its role in the development of black-and-white photographs. Metol is the trade name for the compound 4-(methylamino)phenol sulfate, which is also referred to as Elon in some contexts.

Chemical Properties

Metol is an organic compound with the chemical formula C₇H₉NO. It is a white crystalline solid that is soluble in water. The compound is a derivative of phenol, with a methylamino group attached to the para position of the phenol ring.

Uses in Photography

Metol is primarily used as a developing agent in the photographic industry. It is a key component in many black-and-white film developers, where it acts to reduce silver halides to metallic silver, thus forming the image on the film. Metol is often used in combination with other developing agents, such as hydroquinone, to enhance the development process and improve image quality.

Medical Applications

While Metol is predominantly known for its use in photography, it has also been studied for potential applications in medicine. Its chemical properties allow it to act as a reducing agent, which can be useful in certain biochemical assays and diagnostic tests.

Safety and Handling

Metol should be handled with care, as it can be an irritant to the skin and eyes. Prolonged exposure may lead to allergic reactions in some individuals. It is important to use appropriate personal protective equipment when handling Metol in a laboratory or industrial setting.

History

The use of Metol in photography dates back to the late 19th century. It was first introduced as a photographic developer by the German chemist Andresen in 1891. Since then, it has become a staple in the field of analog photography, valued for its ability to produce fine-grain images with good contrast.

Also see

• Photographic processing
• Developing agent
• Hydroquinone
• Silver halide
• Phenol