"..there are OSHA regulations on radios on worksites.."
There are? Can you point me to the section in 29CFR1910 or 29CFR1926 that states this?
Those are the Federal Regs by which OSHA enforces the Occupational Safety & Health Act of 1970 (the law).
PART 1910 Occupational Safety and Health Standards
PART 1926 Safety and Health Regulations for Construction