Thiourea

Causes severe irritation and burns. May be harmful if swallowed. Avoid breathing vapor or dust. Use with adequate ventilation. Avoid contact with eyes, skin, and clothes. Wash thoroughly after handling. Keep container closed.

Thiourea (also called Thiocarbamide or Sulfourea) is the diamide of thiocarbonic acid that resembles urea but contains sulfur instead of oxygen. 'Thio'  is a chemical prefix indicates the replacement of an oxygen in an acid radical by sulfur with a negative valence of 2; meaning 'Sulfur' derived from the Greek theion. In fact, thiourea occurs as the mixture of two tautomers: S=C(NH2)2 ( Thiourea) + HS=CNHNH2 (Isothiourea), accordingly, provides three functional groups (mino, imino, and thiol).