Which of the following is a disadvantage of using inorganic arsenicals?

Using inorganic arsenicals as wood preservatives has certain disadvantages, and one significant issue is related to moisture content in the wood. When wood is treated with inorganic arsenicals, it often absorbs a significant amount of moisture. If the treated wood is not properly redried after treatment, it can lead to warping and cracking. This is due to the fact that the moisture can cause the wood fibers to swell and subsequently shrink when dried, leading to structural integrity issues.

In contrast, the other options highlight attributes that do not pertain to disadvantages of using inorganic arsenicals. Strong protection from weathering, suitability for heavy industrial use, and improvements in wood longevity are advantages associated with these types of preservatives. Thus, while they offer benefits for wood preservation, the requirement for proper drying after treatment to mitigate warping and cracking is crucial and highlights a key disadvantage.