Expressions (phrases, clauses, etc.), Godan verb with 'ru' ending
to get out of hand; to become uncontrollable; to boil over
see 収拾がつかない
事態の収拾がつかなくなったら、昨日渡した番号で私に電話をかけなさい。If things get out of hand, you should call me at the number I gave you yesterday.
Also written 収拾が付かなくなる【しゅうしゅうがつかなくなる】、収集がつかなくなる【しゅうしゅうがつかなくなる】