"challenging" is ambiguous in context but to not publish/disclose the ratings required in order to completely design a solution fit-for-purpose puts Cisco at a disadvantage. To state that for example a 1240 is designed for warehouses, theatres etc is a little simplistic and we nor Cisco cannot contain the industry verticals in which to operate, again a disadvantage to Cisco.
Designing a solutioin for a vitreous manufacturing plant for example, where fine dust and water dictates the solution, you would want to know that the equipment you are investing in can cope with the environmental challenges in which it is dealt.
Anyway, I have done some digging and come up with the following. I believe this to be as accurate as can be.
Most of Cisco APs for indoor and office use (AP1131, AP1142, AP1242, AP1250) are dust-proof, but not waterproof. In terms of IP rating, that would be around 40, or NEMA 1. See http://en.wikipedia.org/wiki/IP_Code for explanation on IP rating numbering.
Outdoor products include Cisco Bridges (AP1300, AP1400) and mesh APs (1520 series):
Antenna ratings are not published but environmental controls can be viewed on the datasheets.
https://www.cisco.com/en/US/prod/collateral/wireless/ps7183/ps469/product_data_sheet09186a008022b11b_ps6521_Products_Data_Sheet.html
