Bio Productions Blue Contract Urinal Blocks 3kg are an effective, safe and economical way of providing washroom freshness. Free from para Dichlorobenzene (pDCB) a harmful chemical found in many urinal blocks on the market and containing advanced surfactant technology to help keep urinals clean and drains clear and reduces the number of flushes required per day. These blocks are fully soluble in water and contain a stong citrus fragrance which releases throughout the lifetime of the block helping to keep washrooms and urinals smelling fresh. The same blocks are also available in yellow.