while working in the aerospace industry, i was in the position to significantly encouraged management to put up applicable signage, IAW prevailing statutes, on all entrances of our building. not for the employees per se, but to assure those workers who provided appropriate maintance to our facility were aware they could not carry - o or c within the facility/on the property.
now before the unslaught begins from everyone... this avenue was the lesser of two evils, as management, at the prodding from HR, wanted to install metal detectors at the entrances which would of been embarrassing to those of us who were allowed, by senior management, to carry conceal at work in the performance of our position(s) and was unbeknownst to the majority of the employees, including HR.
wabbit
ps: good suggestion, but to further your objective, you might wish to elicit the support of the environmental, health, safety person to adddress/discuss your concerns at the organizational EH&S committee. does two things, one discussion in front of management representatives and puts it on the record employees feel there is a safety issue. additionally, this approach negates your letter might not get past the CEO's watch dog, AKA admin specialist.