Outside, no issue, but if was completely enclosed, you'd need some type of airborne lead mitigation air system. The National Hqs of the NRA in Fairfax VA has that info, but they're focused on commercial ranges.
Thanks for expressing that concern. I did a bit of late-night reading regarding lead mitigation as it applies to gun ranges.
The standards are directed to commercial ranges, I assume because of the references to shooters and employees, and a measurement based on 8 hours of exposure. The numbers relate to large scale operations, but the concentration levels would be proportional.
I could not find a booth to total air volume number, nor did I see a minimum air volume number per booth. There are numbers for rate of exchange and airborne lead particles.
The following is from one of the commercial range ventilation companies:
"Established by NIOSH, the performance intent for firing range ventilation systems shall meet all
the requirements outlined as recommendations and design considerations in HEW publication no.
(NIOSH) 76-130, dated December, 1975, entitled "Lead Exposure Design Considerations for
Indoor Firing Ranges". This design standard prefers an air flow velocity of 75 feet per minute
average on the empty range. This design has consistently provided for the compliance within the
established federal standards for airborne inorganic lead concentration limits.
When properly executed, lead concentrations are consistently maintained below the action level
of 30 micrograms per cubic meter (30ug/m3) in an area where the limit shall not exceed 50
micrograms of lead per cubic meter (50ug/m3) of air over a time weighted average of eight
hours as measured at the respiration zone of the shooters and the range officer when firing from
the firing booths per OSHA 29 CFR. 1910.1025 and 1926.62."
There were several other companies, but they all cite the same reference.
The operative words for me are enclosed, and respiration zone; however, I did find a section describing the actual disbursement of lead and pattern of contamination which was very enlightening. As I understand it in it's most simplistic terms: When you pull the trigger - that sh*t goes everywhere.
I could not locate an ammo specific lead contamination reference, but it obviously will depend on type and volume of shooting. I did find an ad from Federal for plastic coated range ammo - that's going to be another read.
It is very easy to see where a small, enclosed range - like, perhaps a basement, could be very dangerous.
My range is vented, open on one end, and has very limited use. The total air volume is approximately 11,000 cubic feet, the door opening is 200 sq feet, and there are vents; the fan output is over 6,000 CFM. I am no engineer, but I think that will meet the 75 FPM criteria - if not - I'll get a bigger one. Should there be other shooters or visitors, the "respiration zone" is near the open door.
It is unlikely any will be open today, but I do plan to retain the services of a consulting firm to review my range and make any necessary corrections or additions.
Thanks again for bringing this to my attention.