铅室法：以一氧化氮、二氧化氮为催化剂，为较古老的制备硫酸的方法。目前工业上大多用接触法取代铅室法制造硫酸。

二氧化硫在水汽、空气、一氧化氮及二氧化氮共存下反应，可得70％浓度的硫酸，其反应如下：

其硫酸的所得纯度较低，无法除去一氧化氮及二氧化氮，又

所以混有HNO₂及HNO₃。

The lead chamber process was an industrial method used to produce sulfuric acid in large quantities. It has been largely supplanted by the contact process.

In 1746 in Birmingham, England, John Roebuck began producing sulfuric acid in lead-lined chambers, which were stronger, less expensive, and could be made much larger than the glass containers which had been used previously. This allowed the effective industrialization of sulfuric acid production and with several refinements, this process remained the standard method of production for almost two centuries. So robust was the process that as late as 1946, the chamber process still accounted for 25% of sulfuric acid manufactured.