PTFE

Some Gore products use PTFE, a polymer the company says is “of low concern.”

The latter are covered in substances like PTFE, better known as teflon.

The use of PTFE, which left a residue after removal, did not comply with Boeing’s manufacturing specifications.

PTFE, better known as Teflon, has been a very useful chemical since DuPont patented it in 1941.

Teflon itself, a chemical called PTFE, is still in use but becoming less common, in part due to consumer concern.