( CNN ) -- BP plans to continue using a controversial subsea dispersant to break up a plume of oil gushing into the Gulf of Mexico , saying that the leading alternative could pose a risk over the long term , the EPA indicated Saturday . The EPA issued a directive on Thursday , ordering BP to find , within 24 hours , a less toxic but equally effective chemical than its current product , Corexit 9500 -- and one that is available in sufficient quantities . The directive also gave the company 72 hours to stop applying it to the undersea gusher . Corexit has been rated more toxic and less effective than many others on the list of 18 EPA-approved dispersants , according to testimony at a congressional hearing Wednesday . The EPA released BP 's response to the mandate on Saturday . The response , which BP submitted late Thursday night , said that the oil company identified the only other effective , less toxic alternative available in mass quantities as Sea Brat 4 . However , BP said the Sea Brat product `` contains a small amount of a chemical that may degrade to a nonylphenol . '' Nonylphenol is an organic chemical that is toxic to aquatic life and may persist in the environment for years . Corexit , however , `` does not contain chemicals that degrade into NP [ and ] the manufacturer indicates that Corexit reaches its maximum biodegradeablility within 28 days of application '' and does not persist in the environment , BP 's response said . `` Based on the information that is available today , BP continues to believe that Corexit was the best and most appropriate choice at the time when the incident occurred , and that Corexit remains the best option for subsea application , '' BP said . Despite the continuing use of Corexit , BP is not in violation of the EPA directive , which said that should the company not be able to identify alternative products , `` BP shall provide ... a detailed description of the products investigated [ and ] the reason the products did not meet the standards '' required by the agency . `` We will continue to review and discuss the science through the end of the 72-hour window on Sunday , and then we will reach a decision , '' an EPA spokesman said Saturday . John Sheffield , president of Alabaster Corp. , which manufactures Sea Brat , took issue with BP 's response , saying Saturday that the company is `` nitpicking my product because they want to use what they 've always used . '' Sheffield told CNN that he discussed the nonylphenol issue with EPA officials earlier this week , saying the chemical makes up less than 1 percent of the Sea Brat dispersant . `` I 've already diffused this issue with the EPA , '' he said , adding the agency `` accepted that response days ago . '' The EPA has not yet publicly issued a formal response to BP 's letter . EPA officials met with BP executives on Friday to discuss the issue and to explore alternatives . The EPA said Saturday that it `` will continue to work over the next 48 hours to ensure BP is complying with the directive , '' but did not respond to requests for additional comment . Meanwhile , the Department of Homeland Security announced Saturday that Interior Secretary Ken Salazar and Homeland Security Secretary Janet Napolitano will lead a bipartisan Senate delegation to inspect the Louisiana coastline after globs of thick , heavy oil began washing into some of the state 's marshlands this week . The delegation will meet with federal officials and BP representatives to discuss the ongoing response efforts . CNN 's Ed Lavandera contributed to this report .
EPA says it `` will continue to work over the next 48 hours to ensure BP is complying '' EPA issued directive to find less toxic chemical than Corexit , the current dispersant in use . The agency said that if there are any new developments on this front, they would update their press release with them. '' BP maintains ` ` Corexit was the best and most appropriate choice ''