Rock salt in its native form should not contain any synthetic organic compounds. The chemical
composition findings in this study are supported by the Assale and Khewra rock salt studies.
Calcium was detected in only one of the samples. If the detection limits of calcium were lower,
it should have been detected in all of the DEP’s rock salt samples. The trace chemicals in rock
salt samples could vary depending upon the location and geologic time when the salt deposit was
formed.