Regarding the international dosage regulations for DMDMH

The maximum allowable usage of DMDMH preservatives is influenced by regulations in different countries and regions. Some jurisdictions may establish stricter limits to safeguard consumer rights and health.
Manufacturers using DMDMH preservatives or other preservatives should adjust usage promptly according to different markets to ensure compliance with local laws and regulations.
In the United States, Europe, Japan, and China, DMDMH is permitted for use. The highest permitted addition in the United States is 0.6% (active ingredient). For formaldehyde-releasing preservatives, the standards in China align completely with those in Europe and the United States.
However, in Japan, DMDMH is only permitted in rinse-off cosmetics that do not come into contact with mucous membranes, with the highest permitted addition being 0.3% (active ingredient).