I'll give two answers:
1) Memory, such that is there were minimum "dress code" requirements when I was on the extra gang in 1956. In general typical work clothes. Steel toe shoes optional, hats optional ( hard, soft, or none), shirts optional. etc.) There were baseball type shin guards issued to the Adzer operators. (Adzer mechanically planed off the old tie plate marks).
2) In 2005 when I was observing work on/over the R/W for the railroad (while working for a consultant), FRA Part 214 regulation applied. They are available in a 6 ¾" x 4" x 1/4"(thick) spiral bound pamphlet. In the 07/07/2005 edition it list such things in paragraph (214.111) on Personal protective equipment plus sub paragraphs on, Head protection (214.113), Foot protection (214.115) , Eye and Face protection (214.117). CSX in it's supplement required Orange Vests witn no mention of the brilliant yellow-green which I unofficially allowed the contractor's sub-contractor's employees to wear.
The "kicker" that causes me to say that OSHA regulations are "puny" is the provision which they show in Appendix "A", Civil Penalties is the fines for violations that are on the individuals (not the company) in Paragraph 214.313 of $1,000 to $3,000