Why is 1,1,1-Trichlorethane sometimes used instead of Trichlorethylene?

1,1,1-Trichloroethane is sometimes used instead of trichloroethylene primarily due to its higher permissible exposure limit or Threshold Limit Value (TLV). A higher TLV indicates that workers can be exposed to this chemical for longer periods without experiencing harmful health effects compared to substances with lower TLVs. This makes 1,1,1-Trichloroethane a more favorable choice in terms of safety in industrial applications, as it reduces the risk associated with exposure.

The higher TLV reflects the compound's relative safety profile and can lead to reduced regulatory burdens in environments where exposure levels can be controlled. This characteristic is particularly valuable in settings where prolonged exposure might occur, allowing for a more practical application in comparison to trichloroethylene.

In contrast, while cost may be a consideration, it is not necessarily the defining factor for the selective use of one compound over another. The boiling point and toxicity levels are also critical considerations in chemical safety and application, but the primary advantage of 1,1,1-Trichloroethane in this context lies in its higher TLV, allowing for wider usability in occupational health scenarios.