Cartons may absorb or give out moisture under varying atmospheric conditions and carton material will equalize with the moisture content of the air surrounding it in about 36 hours. Thus cartons of goods from a damp area may be relatively full of moisture when loaded into a hold or container. A moisture content of less than 12% in the is usually considered safe from this particular problem. It has been known for carton material to be wetted by the packers of goods to make the material more flexible and easier to put into shape prior to filling with canned goods. A container load or a compartment load of carton goods can therefore have a very high volume of moisture inherent in the cartons at the time of loading, with subsequent possible problems of condensation (see “Ventilation”).