Is alt="" appropriate in some situations for html img tag?

We have a project that is all about web accessibility compliance. About a week from launch we have the accessibility committee reviewing our site to give the final thumbs up. However, they reported back to us that we should set alt="" on some of our icons because they do not provide any additional content to the site and thus are merely distracting to a screen reader but yield no benefit.

1. Is this correct?
2. I was under the impression alt was a required attribute of img? Sure alt="" on an img tag would include the alt attribute but is this valid ?

Comments are appreciated.

If the icons provide any functionality (user-clickable or something), I'd recommend setting a descriptive alt value. If they are just decorative, then alt="" is valid.

From the standard:

While alternate text may be very helpful, it must be handled with care. Authors should observe the following guidelines:

• Do not specify irrelevant alternate text when including images intended to format a page, for instance, alt="red ball" would be inappropriate for an image that adds a red ball for decorating a heading or paragraph. In such cases, the alternate text should be the empty string (""). Authors are in any case advised to avoid using images to format pages; style sheets should be used instead.
• Do not specify meaningless alternate text (e.g., "dummy text"). Not only will this frustrate users, it will slow down user agents that must convert text to speech or braille output.