Proteins are chains of amino acids that fold to form very unique structures. The way these chains fold gives proteins the proper shape and the flexibility to interact with other molecules. Formaldehyde diffuses into tissues and cells where it forms crosslinks between different amino acids. This property makes formaldehyde useful for a number of chemical processes that fix things in a particular state. Formaldehyde doesn't stick around long in your body because it is so rapidly metabolized to formic acid by the second enzyme in this metabolic pathway.
Formic acid is also extremely toxic to humans.
It disrupts the function of a cell's mitochondria . Not only do all the cellular processes stop for lack of energy, but the cells themselves are blown apart by a massive accumulation of different molecules involved in energy production. The cells that make up the optic nerve are exquisitely sensitive to formic acid, which is why blindness is so closely associated with methanol poisoning. The short answer is no. Most people regularly consume up to 10 mg of methanol per day as part of their normal diet.