 After the passage of the act, soda ash producers were obliged to absorb the waste gas in water, producing hydrochloric acid on an industrial scale.In the 20th century, the Leblanc process was effectively replaced by the Solvay process without a hydrochloric acid by-product.Since hydrochloric acid was already fully settled as an important chemical in numerous applications, the commercial interest initiated other production methods, some of which are still used today.