For example, for the Gases under pressure hazard class, the hazard categories are Compressed gas, Liquefied gas, Refrigerated liquefied gas and Dissolved gas. These classes relate to the physical state of the gas when packaged and do not describe the degree of hazard.
1 In 1596, a flush toilet was invented and built for Queen Elizabeth I by her Godson, Sir John Harrington. 2  The first patent for the flushing toilet was issued to Alexander Cummings in 1775. 3  During the 1800s, people realized that poor sanitary conditions caused diseases.
1 In 1799 a Frenchman by the name of Pochon invented the first hand cranked dryer. 2  In 1843 John E. Turnbull of Saint John, New Brunswick patented the first wringer washer. 3  He called it the  Clothes Washer with Wringer Rolls 4  . In 1851 James King patented the first washing machine that used a drum.t is impossible to know exactly who invented the first washing machine and dryer. Some of the patents are so old that nothing is known about the original patent holder. 1  The first British patent for a washing machine was issued in 1691.