, ▁and ▁tin ▁can s . ▁Non - fer r ous ▁met als ▁are ▁e ject ed ▁by ▁magnetic ▁ed dy ▁curr ents ▁in ▁which ▁a ▁rot ating ▁magnetic ▁field ▁indu ces ▁an ▁electric ▁current ▁around ▁the ▁al umin um ▁can s , ▁which ▁in ▁turn ▁creates ▁a ▁magnetic ▁ed dy ▁current ▁inside ▁the ▁can s . ▁This ▁magnetic ▁ed dy ▁current ▁is ▁rep uls ed ▁by ▁a ▁large ▁magnetic ▁field , ▁and ▁the ▁can s ▁are ▁e ject ed ▁from ▁the ▁rest ▁of ▁the ▁rec y cl ate ▁stream . ▁ ▁Finally , ▁glass ▁is ▁sorted ▁according ▁to ▁its ▁color : ▁brown , ▁am ber , ▁green , ▁or ▁clear . ▁It ▁may ▁either ▁be ▁sorted ▁by ▁hand , ▁or ▁via ▁an ▁autom ated ▁machine ▁that ▁uses ▁colored ▁filters ▁to ▁detect ▁different ▁colors . ▁G lass ▁fragments ▁smaller ▁than ▁ ▁across ▁cannot ▁be ▁sorted ▁automatically , ▁and ▁are ▁mixed ▁together ▁as ▁" glass ▁fin es ". ▁ ▁This ▁process ▁of ▁rec y cling ▁as ▁well ▁as ▁re using ▁the ▁rec yc led ▁material ▁has ▁proven ▁advantage ous ▁because ▁it ▁reduces ▁amount ▁of ▁waste ▁sent ▁to ▁land fill s , ▁conser ves ▁natural ▁resources , ▁saves ▁energy , ▁reduces ▁green house ▁gas ▁em issions , ▁and ▁helps ▁create ▁new ▁jobs . ▁Rec yc led ▁materials ▁can ▁also ▁be ▁converted ▁into ▁new ▁products ▁that ▁can ▁be ▁consum ed ▁again , ▁such ▁as ▁paper , ▁pl astic , ▁and ▁glass . ▁ ▁The ▁City ▁and ▁County ▁of ▁San ▁Francisco ' s ▁Department ▁of ▁the ▁Environment