Chemical contaminants present in foods are often unaffected by thermal processing (unlike most microbiological agents). Chemical contaminants can be classified according to the source of contamination and the mechanism by which they enter the food product.nvironmental contaminants are chemicals that are present in the environment in which the food is grown, harvested, transported, stored, packaged, processed, and consumed. The physical contact of the food with its environment results in its contamination. Possible sources of contamination include:
For the record,  cfprefsd is a fundamental part of the MacOS operating system. It's a tool developers use when they write their application, and allows an application to read/write/modify preferences files (like files ending in .plist, and others).
CD-RW (Compact Disc-ReWritable) is a digital optical disc storage format. A CD-RW disc is a compact disc that can be written, read arbitrarily many times, erased and written again.The technology was introduced in 1997.CD-RW discs (CD-RWs) require readers that have more sensitive laser optics than plain CDs.Consequently, CD-RWs cannot be read in many CD readers built prior to the introduction of CD-RW. CD-ROM drives that bear a MultiRead certification claim compatibility.CD-RW discs need to be blanked before reuse.D-RW discs (CD-RWs) require readers that have more sensitive laser optics than plain CDs. Consequently, CD-RWs cannot be read in many CD readers built prior to the introduction of CD-RW. CD-ROM drives that bear a MultiRead certification claim compatibility. CD-RW discs need to be blanked before reuse.