# § 955. State laws
**(a)** No State law in effect on December 30, 1969 or which may become effective thereafter shall be superseded by any provision of this chapter or order issued or any mandatory health or safety standard, except insofar as such State law is in conflict with this chapter or with any order issued or any mandatory health or safety standard.
**(b)** The provisions of any State law or regulation in effect upon the operative date of this chapter, or which may become effective thereafter, which provide for more stringent health and safety standards applicable to coal or other mines than do the provisions of this chapter or any order issued or any mandatory health or safety standard shall not thereby be construed or held to be in conflict with this chapter. The provisions of any State law or regulation in effect on December 30, 1969, or which may become effective thereafter, which provide for health and safety standards applicable to coal or other mines for which no provision is contained in this chapter or in any order issued or any mandatory health or safety standard, shall not be held to be in conflict with this chapter.
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**Source Credit**: (Pub. L. 91–173, title V, § 506, Dec. 30, 1969, 83 Stat. 803; Pub. L. 95–164, title III, § 303(e), Nov. 9, 1977, 91 Stat. 1321.)
## Editorial Notes
### References in Text
This chapter, referred to in text, was in the original “this Act”, meaning , , , known as the Federal Mine Safety and Health Act of 1977, which is classified principally to this chapter. For complete classification of this Act to the Code, see Short Title note set out under and Tables.
For the operative date of this chapter, referred to in subsec. (b), see , set out as an Effective Date note under .
### Amendments
1977—Subsec. (b). inserted reference to mines other than coal mines.
## Statutory Notes and Related Subsidiaries
### Effective Date of 1977 Amendment
Amendment by effective 120 days after , except as otherwise provided, see , set out as a note under .