is the measurement of the ultraviolet absorption of
petroleum products, determined by standardized
tests, such as ASTM-D- 2008.
Aromatics absorb more ultraviolet light than do
naphthenes and paraffins,
and the amount of absorbance can be used as an indication of the amount of
aromatics in a product. Certain polynuclear aromatics (PNAs)
are known carcinogens (cancer-causing
substances), with peaks of absorbance generally between 280 and 400
millimicrons. The Food and Drug Administration (FDA) has therefore
imposed limits on the amount of ultraviolet absorbance at these wavelengths
for materials classified as food additives. However, not all materials with
ultraviolet absorbance at these wavelengths are carcinogenic.
Application
Notes:
