Polyacrylamide is a polymer (-CH₂CHCONH₂-) formed from acrylamide

Acrylamide

Acrylamide is a chemical compound with the chemical formula C3H5NO. Its IUPAC name is prop-2-enamide. It is a white odourless crystalline solid, soluble in water, ethanol, ether, and chloroform. Acrylamide is incompatible with acids, bases, oxidizing agents, iron, and iron salts...

 subunits. It can be synthesized as a simple linear-chain structure or cross-link

Cross-link

Cross-links are bonds that link one polymer chain to another. They can be covalent bonds or ionic bonds. "Polymer chains" can refer to synthetic polymers or natural polymers . When the term "cross-linking" is used in the synthetic polymer science field, it usually refers to the use of...

ed, typically using N,N-methylenebisacrylamide. Polyacrylamide is not toxic. However, unpolymerized acrylamide, which is a neurotoxin

Neurotoxin

A neurotoxin is a toxin that acts specifically on nerve cells , usually by interacting with membrane proteins such as ion channels. Some sources are more general, and define the effect of neurotoxins as occurring at nerve tissue...

, can be present in very small amounts in the polymerized acrylamide, therefore it is recommended to handle it with caution.