Umm no. There's no way to shield the chip short of wearing a tinfoil glove. Your employer would not be the only one trying to use the chip. Even smart cards, like the militaries CAC, have to be shielded for security. And, yes, I've seen briefcase sized card readers with several feet of range.

FWIW, I've been using these to protect transponder cards

http://www.idstronghold.com/Secure_Badgeholder_Duolite_IDSH2004.asp#productTabs1
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