safety rail vs guardrail

safety rail and guardrail both are nouns.

Word	Noun	Adjective	Verb	Adverb
safety rail	Yes	No	No	No
guardrail	Yes	No	No	No

As nouns, safety rail and guardrail are synonyms defined as:

safety rail and guardrail: a railing placed alongside a stairway or road for safety

safety rail (noun)	guardrail (noun)
a railing placed alongside a stairway or road for safety	a railing placed alongside a stairway or road for safety