2.—(1) Subject to sub-paragraph (2), an activity shall not be taken to be a Part B activity if it cannot result in the release into the air of a substance listed in paragraph 12 or there is no likelihood that it will result in the release into the air of any such substance except in a quantity which is so trivial that it is incapable of causing harm or its capacity to cause harm is insignificant.
(2) Sub-paragraph (1) does not apply to an activity which may give rise to an offensive smell noticeable outside the site where the activity is carried out.