In 1934, the Chimney Sweeps Act, not to be confused with the Chimney Sweepers Act of 1875, was passed outlawing the apprenticing of any child below the age of ten. No child below the age of 14 was to actually be engaged in cleaning chimneys. In 1840, a revised Chimney Sweeps Act raised the minimum age of apprenticeship to 16. As with earlier legislation, this was largely ignored due to the absence of any means of enforcement. Children younger than ten were still being made to climb chimneys.  The final Act in 1875 was the date parliament brought about the end of the chimney climbing boys. This act passed following the death of a 12 year old climbing boy whose master forced him to climb. This act required the registration and supervision of all chimney sweeps and to be enforcable by the police.

Work Cited:

UK Parliament, "Children and Chimneys," https://www.parliament.uk/about/living-heritage/transformingsociety/livi...

Wikipedia, Chimney Sweepers Act 187, https://en.wikipedia.org/wiki/Chimney_Sweepers_Act_1875