Carbon tetrachloride is a colorless liquid with a sweet smell that can be detected at low levels. Once widely used as an industrial solvent, a dry-cleaning solvent; and its use has been greatly reduced as a refrigerant. Carbon tetrachloride is one of the most potent hepatotoxins (toxic to the liver). Prior to the Montreal Protocol, large quantities of carbon tetrachloride were used to produce chlorofluorocarbon refrigerants . . . potent ozone-depleting substances. Carbon tetrachloride is also a greenhouse gas. Carbon tetrachloride is still used in the paint and coating shop at the facility. The company installed ventilation hoods over the tanks of carbon tetrachloride where parts are coated and performed air quality monitoring to evaluate their efforts' effectiveness. The table below provides the results of sampling conducted in the breathing zone of one of its workers.

Calculate the 8-hour time-weighted average (TWA) of worker exposure based on the information provided below to determine if the worker has been exposed above the OEL.

Calculate to one decimal point include the unit of measurement i.e., 14.6 ppm. Blank 1

Was this worker exposed to this chemical above the PEL-TWA? (yes or no) Blank 2

Was this worker exposed to this chemical above the TLV-TWA? (yes or no) Blank 3