( ( Some companies ) ( even ( ( stopped ( ( ( ( producing products ) ( with ( possible allergens ) ) ) -- ) ( substances ( that ( can ( cause ( allergic reactions ) ) ) ) ) ) ) . ) ) )
(ROOT (S (NP (DT Some) (NNS companies)) (ADVP (RB even)) (VP (VBD stopped) (NP (NP (NP (VBG producing) (NNS products)) (PP (IN with) (NP (JJ possible) (NNS allergens)))) (: --) (NP (NP (NNS substances)) (SBAR (WHNP (WDT that)) (S (VP (MD can) (VP (VB cause) (NP (JJ allergic) (NNS reactions))))))))) (. .)))
Some companies even stopped producing products with possible allergens -- substances that can cause allergic reactions.
(ROOT (S (NP (NP (NNS Substances)) (VP (VBN produced) (PP (IN by) (NP (DT a) (NN reaction))))) (VP (VBP are) (VP (VBN known) (PP (IN as) (NP (NNS products))))) (. .)))