Is there any reference in the NEC or UBC 1997 that requires the use of a commercial rated washer or dryer in a commercial beauty salon?

They wash / dry a load or two of hand towels daily.

They want to use a residential washer/dryer and I think the only drawback is that the manufacturers warranty will be void, but want to double check.

Thanks,
--Mario

[This message has been edited by Load-n-Code (edited 01-21-2005).]