Tin whiskers form when tin plating on component leads is under pressure. The tin squeezes out to form filaments as thin as a human hair. The whiskers grow long enough to potentially cause a short circuit. This concern has come about since the European Union adopted restricition of hazardous substances, which has led manufacturers to start using tin instead of a mixture with lead, the objectionable element.
The issue of tin whiskers is less likely than solder joint thermal failure or mechanical disk drive failure, but the cause can be hidden and diagnosing the issue can be a huge expense. There are a few undertakings by the industry to mitigate this problem, such as mixing the tin with other materials or using thin coatings, such as a layer of nickel to prevent copper from diffusing into the tin.
While there is a little a facility can do to prevent a problem caused inside these components, keeping a clean data center can help with this and other failure issues. Keeping a data center clean helps remove contaminants that can enter computer equipment and potentially dislodge tin whiskers that cause short circuits.