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).
AutoCAD drawing set description files are settings files saved in the DSD format, and these DSD files are also called properties files. The AutoCAD 2013 software creates and uses files appended with the .dsd extension. This application is classified as CAD productivity software, and the data in a DSD file usually consists of settings or details used for the publication of digital drawings stored in DWF formats.