Polymer degradation into the bore of the pipe, and fuel leakage and fire may follow. The problem of ozone cracking can be prevented by adding anti-ozonants to the rubber before vulcanization. Ozone cracks were commonly seen in automobile tire sidewalls, but are now seen rarely thanks to these additives. On the other hand, the problem does recur in unprotected products such as rubber tubing and seals. The polymers are susceptible to attack by atmospheric oxygen, especially at elevated temperatures encountered during processing to shape. Many process methods such as extrusion and injection moulding involve pumping molten polymer into tools, and the high
Sulfur 14th century the Latin ' was restored, for '; and by the 15th century the full Latin spelling was restored, for "sulfur, sulphur". The parallel "f~ph" spellings continued in Britain until the 19th century, when the word was standardized as "sulphur". "Sulfur" was the form chosen in the United States, whereas Canada uses both. The IUPAC adopted the spelling "sulfur" in 1990, as did the Nomenclature Committee of the Royal Society of Chemistry in 1992, restoring the spelling "sulfur" to Britain. Oxford Dictionaries note that "in chemistry and other technical uses ... the "-f-" spelling is now the standard form