Under 18 U.S.C. 1716, all matter that is outwardly or of its own force dangerous or injurious to life, health, or property is nonmailable. The knowing deposit of such matter in the mail is a crime punishable by fine, imprisonment, or other penalty. However, certain hazardous materials and otherwise restricted and perishable matter may be mailed under the conditions permitted in DMM 601.8–11 and this publication.