17 2 Hazards commonly include Hazar dous A tmosphere Lo w o xy gen 2 1 is normal less than 1 95 is hazar dous Carbon mono xide Flammable Gases Loose R ock LooseR o tt en Timber s Open Holes U nsaf e Ladder s in Raises P oor Visibility Animals Bear s Bats Deep W at er Hazardous A tmosphere Do no t ent e r t o e xplore abandoned openings unless y ou ha v e and kno w ho w t o use a multigas de t ect or Lo w o xy gen and hazar dous gases will pr obably be present Ev en the dripping of w at er can cause the generation of deadly h ydr ogen sulphide gas One of y our best def ences is good v entilation which will pr obably no t be present on initial e xploration Loose R oc k Be aler t f or areas of loose r ock which could f all une xpect edly U nless y ou ha v e been trained on pr oper scaling me thods y ou should a v oid att em pting t o tak e do wn loose r ock If y ou see areas where r ock has f allen fr om the w alls or r oof do no t pr o ce e d u ntil the are a has be e n made saf e b y a q u alife d pe r son LooseR o tt en Timber s Man y old w or kings ma y use timber s f or gr ound suppor t Be aler t f or br ok en timber s and if y ou see these areas do no t pr oceed Constantly check the timber s f or r o t using a knif e or hammer