Dimethicone, also known as polydimethylsiloxane, is a silicon-based polymer that is a man-made synthetic molecule made up of repeating units called monomers. Silicon is the second most abundant element in the Earth's crust after oxygen, and silicon dioxide is also known as sand, commonly found on beaches and shores.
In regards to a job, a refusal letter is written when a company offers a position to an individual who must refuse due to his or her circumstances, such as already having accepted another offer, or simply a lack of interest in this particular job.
Yes, always assess. When a patient is refusing to do something, you try to give them a logical explanation why they should do it. They do have the right to refuse, so you can't force them to do anything. Then, investigate to see if there's something to explain why they are refusing.