"White lead pigment in paint had been recognized as toxic and restricted since 1915; it had been banned from professional use since 1926 and from craft work since 1948."[0]
Wikipedia's citation[1] does appear to be a delcaration from 1909 stating:
"ART. 2. - A l'expiration de la cinquième année qui suivra la promulgation de la présente loi, l'emploi de la céruse, de l'huile de lin plombifère et de tout produit spécialisé renfermant de la céruse, sera interdit dans tous les travaux de peinture de quelque nature qu'ils soient, exécutés par les ouvriers peintres, tant à l'extérieur qu'à l'intérieur des bâtiments_"
Translated using https://www.deepl.com/translator : "ART. 2 - At the end of the fifth year following the promulgation of the present law, the use of ceruse, leaded linseed oil and any specialized product containing ceruse, will be prohibited in all painting work of any nature whatsoever, carried out by painters, both outside and inside buildings." ("ceruse" is white lead.)
This supports the 1915 (the fifth year following 1909) in the first article.
I found this article:
"White lead pigment in paint had been recognized as toxic and restricted since 1915; it had been banned from professional use since 1926 and from craft work since 1948."[0]
Wikipedia's citation[1] does appear to be a delcaration from 1909 stating: "ART. 2. - A l'expiration de la cinquième année qui suivra la promulgation de la présente loi, l'emploi de la céruse, de l'huile de lin plombifère et de tout produit spécialisé renfermant de la céruse, sera interdit dans tous les travaux de peinture de quelque nature qu'ils soient, exécutés par les ouvriers peintres, tant à l'extérieur qu'à l'intérieur des bâtiments_"
Translated using https://www.deepl.com/translator : "ART. 2 - At the end of the fifth year following the promulgation of the present law, the use of ceruse, leaded linseed oil and any specialized product containing ceruse, will be prohibited in all painting work of any nature whatsoever, carried out by painters, both outside and inside buildings." ("ceruse" is white lead.)
This supports the 1915 (the fifth year following 1909) in the first article.
[0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1448552/
[1] https://solidarites-sante.gouv.fr/fichiers/numerisations3/bu... (p202 of the PDF, p172 by the original document page numbers)