37 Of 365

37 Of 365

"Tin cans were invented in England by merchant Peter Durand, who received a patent for it in 1810. The first canning factory opened in England in 1813."

"Most cans are right circular cylinders with identical and parallel round tops and bottoms with vertical sides. However, where the small volume to be contained and/or the shape of the contents suggests it, the top and bottom may be rounded-corner rectangles or ovals. Other contents may justify a can that is overall somewhat conical in shape.

The fabrication of most cans results in at least one “rim”, a narrow ring whose outside diameter is slightly larger than that of the rest of the can. The flat surfaces of rimmed cans are recessed from the edge of any rim (toward the middle of the can) by about the width of the rim; the inside diameter of a rim, adjacent to this recessed surface, is slightly smaller than the inside diameter of the rest of the can.”

"Cans come in a variety of shapes. Two common ones are the "soup tin" or the "tuna tin." Walls are often stiffened with ribs, especially on larger cans, to help the can resist dents that can cause seams to split."

"Although tin is corrosion resistant, acidic food like fruits and vegetables can cause corrosion of the tin layer. Nausea, vomiting, and diarrhea have been reported after ingesting canned food containing 200 mg/kg of tin.A 2002 study showed that 99.5% of 1200 tested cans contained below the UK regulatory limit of 200 mg/kg of tin, an improvement over most previous studies largely attributed to the increased use of fully lacquered cans for acidic foods, and concluded that the results do not raise any long term food safety concerns for consumers. The two non-compliant products were voluntarily recalled.”

“Evidence of tin impurities can be indicated by color, as in the case of pears, but lack of color change does not guarantee that a food is not tainted with tin.”