Uses and health risk of Cyclopentane

Cyclopentane is a highly flammable alicyclic hydrocarbon with chemical formula C5H10 and CAS number 287-92-3, consisting of a ring of five carbon atoms each bonded with two hydrogen atoms above and below the plane. It occurs as a colorless liquid with a petrol-like odor. 

Struture

Cyclopentane in planar conformation has no angle strain, but suffers from the eclipsing strain. This leads to the preference for the two nonplanar conformations, namely envelope and the half-chair conformations. The envelope conformation, with presence of plane of symmetry, belongs to CS point group and the half-chair conformer belongs to C2 point group. 

The envelope conformer has four atoms in a plane and the fifth carbon atom is out of the plane. While the half-chair conformer has three carbons in the same plane and the remaining two, alternately above and below the plane.  The nonplanar conformations have C–C–C bond angles between 102° and 106°. The envelope conformer is more stable than the half-chair conformation by 0.5 kcal/mol.  The envelope is also more stable than the planar conformation by 5.0 kcal/mol. In cyclopentane, the interconversion between different conformation occurs via pseudo-rotation. 

Uses

Cyclopentane is used in the manufacture of synthetic resins and rubber adhesives and also as a blowing agent in the manufacture of polyurethane insulating foam, and is found in many domestic appliances such as refrigerators and freezers, replacing alternatives such as CFC-11 and HCFC-141b.

Multiply alkylated cyclopentane (MAC) lubricants have low volatility and are used in some specialty applications.

Health risk

Routes of exposure

The substance can be absorbed into the body by inhalation of its vapour. 

Effects of short-term exposure

The substance and the vapour in high concentrations are irritating to the eyes and respiratory tract. The substance is irritating to the gastrointestinal tract. If swallowed the substance easily enters the airways and could result in aspiration pneumonitis. The substance may cause effects on the central nervous system. This may result in lowering of consciousness. 

Inhalation risk

A harmful contamination of the air can be reached rather quickly on evaporation of this substance at 20°C. 

Effects of long-term or repeated exposure.

Repeated or prolonged contact with skin may cause dryness and cracking and dermatitis.