Tin pest is an autocatalytic, allotropic transformation of the element tin, which causes deterioration of tin objects at low temperatures. Tin pest has also been called tin disease, tin blight or tin leprosy (Lèpre d'étain).

It was observed in medieval Europe that the pipes of church pipe organs were affected in cool climates. As soon as the tin began decomposing, the process accelerated.

With the adoption of the Restriction of Hazardous Substances Directive (RoHS) regulations in Europe, and similar regulations elsewhere traditional lead/tin solders have been replaced by solders containing primarily tin, making prevention of tin pest (and related problems such as tin whiskers) a modern (21st century) technological challenge.

At 13.2 degrees Celsius (about 56 degrees Fahrenheit) and below, pure tin transforms from the silvery, ductile metallic allotrope of β-form white tin to brittle, nonmetallic, α-form grey tin. The transformation is slow to initiate due to a high activation energy but the presence of germanium (or crystal structures of similar form and size) or very low temperatures ~-30 degrees Celsius aids the initiation. There is also a volume increase associated with the phase change. Eventually the α-form decomposes into powder, hence the name tin pest.

Tin ( /ˈtɪn/ TIN) is a chemical element with the symbol Sn (for Latin: stannum) and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4. Tin is the 49th most abundant element and has, with 10 stable isotopes, the largest number of stable isotopes in the periodic table. Tin is obtained chiefly from the mineral cassiterite, where it occurs as tin dioxide, SnO₂.

This silvery, malleable post-transition metal is not easily oxidized in air and is used to coat other metals to prevent corrosion. The first alloy, used in large scale since 3000 BC, was bronze, an alloy of tin and copper. After 600 BC pure metallic tin was produced. Pewter, which is an alloy of 85–90% tin with the remainder commonly consisting of copper, antimony and lead, was used for flatware from the Bronze Age until the 20th century. In modern times tin is used in many alloys, most notably tin/lead soft solders, typically containing 60% or more of tin. Another large application for tin is corrosion-resistant tin plating of steel. Because of its low toxicity, tin-plated metal is also used for food packaging, giving the name to tin cans, which are made mostly of steel.

Pest may refer to:

Places: