, ▁the ▁play ground ▁equipment ▁above ▁the ▁surface ▁may ▁be ▁totally ▁destroyed . ▁Sand ▁and ▁gra vel : ▁The ▁extent ▁to ▁which ▁these ▁surfaces ▁meet ▁safety ▁standards ▁depends ▁on ▁the ▁exact ▁type ▁and ▁depth ▁of ▁the ▁material ▁used . ▁When ▁sand ▁is ▁wet , ▁the ▁surface ▁becomes ▁hard ▁and ▁un y ield ing . ▁In ▁such ▁a ▁condition , ▁the ▁ability ▁of ▁a ▁sand ▁surface ▁to ▁abs orb ▁impact ▁is ▁seriously ▁comprom ised . ▁Ne ither ▁sand ▁nor ▁pe a ▁gra vel ▁meet ▁the ▁requirements ▁of ▁the ▁Americans ▁with ▁Dis abilities ▁Act ▁for ▁wheel ch air ▁access ibility . ▁ ▁Ro le ▁of ▁I PE MA ▁In ▁the ▁United ▁States ▁and ▁Canada ▁the ▁International ▁Play ▁Equ ip ment ▁Man ufact ur ers ▁Association ▁( I PE MA ) ▁provides ▁a ▁third - party ▁cert ification ▁service ▁enabled ▁by ▁appoint ing ▁a ▁testing ▁labor atory ▁to ▁determine ▁if ▁a ▁particular ▁surface ▁con forms ▁to ▁A ST M ▁standards ▁F 1 2 9 2 , ▁F 1 9 5 1 , ▁and ▁F 2 0 7 5 . ▁I PE MA ’ s ▁se al ▁on ▁a ▁provider ’ s ▁document ▁is ▁clear ▁evidence ▁that ▁the ▁covered ▁material ▁has ▁met ▁these ▁tests . ▁O wner / oper ators ▁should ▁request ▁a ▁copy ▁of ▁this ▁cert ification ▁for ▁their ▁own ▁protection . ▁Some ▁supp liers ▁do ▁not ▁offer ▁proof ▁of ▁cert ification ▁and ▁mere ▁membership ▁in ▁I PE MA ▁does ▁not ▁mean ▁that ▁a ▁particular ▁supp lier ’ s ▁material ▁has ▁been ▁cert ified . ▁A