Mechanical pencil applied at an angle. When excess vertical pressure is applied on the lead, the lead is automatically retracted inwards. Higher-end mechanical pencils often feature a lead hardness grade indicator and sometimes feature a retractable lead guide pipe. This allows the lead guide pipe to retract back into the pencil body, which will keep it protected in storage and during transit and makes it 'pocket-safe'. In spite of the name, pencil leads do not contain the toxic chemical element lead, but are typically made with graphite and clay, or plastic polymers. Compared to standard pencils, mechanical pencils have a smaller range
Lead poisoning contamination include industrial use of lead, such as is found in facilities that process lead-acid batteries or produce lead wire or pipes, and metal recycling and foundries. Storage batteries and ammunition are made with the largest amounts of lead consumed in the economy each year, in the US as of 2013. Children living near facilities that process lead, such as lead smelters, have been found to have unusually high blood lead levels. In August 2009, parents rioted in China after lead poisoning was found in nearly 2000 children living near zinc and manganese smelters. Lead exposure can occur from contact