The AATCC and other testing and development groups have used standard reference detergents since the 1960s. AATCC Standard Reference Detergent 124 and WOB (without brightener) were the first formulations adopted by the AATCC to represent typical home laundering products of that era, primarily phosphate-built powder detergents. The proliferation of detergent formula variations and the elimination of phosphate due to environmental pressures made Standard Reference Detergents 124 and WOB obsolete. Since the discontinuation of 124 and WOB, new representative detergents have been available for use. The following paragraphs provide some perspective on laundry detergent trends and the AATCC standard reference detergents.