The U.S. Environmental Protection Agency (EPA) is ratcheting up its scrutiny of nanoscale chemicals amid concerns that they could pose unique environmental and health risks. Late last month, the agency proposed requiring companies to submit data on industrial nanomaterials that they already make and sell. Observers say EPA’s move could be a prelude to tighter federal regulation of nanomaterials, which have begun to show up in consumer products.For years, EPA has grappled with whether and how to use the Toxic Substances Control Act (TSCA), the nation’s leading chemical regulation law, to handle nanomaterials. TSCA is silent on nanoproducts, generally defined as materials composed of structures between 1 and 100 billionths of a meter. But many environmental groups worry that they potentially carry unknown risks by virtue of their size. Other observers, however, have argued that size alone shouldn’t trigger new regulation and that existing rules are adequate to deal with the new products.EPA’s 25 March proposal actually walks back an earlier version—now scrapped—that would have let the agency more easily clamp down on any new uses of nanomaterials. Still, the weaker version being proposed now represents the first time EPA would use its powers under TSCA to request information specifically on nanomaterials. (The proposal comes as Congress is debating revamping TSCA, which has drawn extensive criticism.)Sign up for our daily newsletterGet more great content like this delivered right to you!Country *AfghanistanAland IslandsAlbaniaAlgeriaAndorraAngolaAnguillaAntarcticaAntigua and BarbudaArgentinaArmeniaArubaAustraliaAustriaAzerbaijanBahamasBahrainBangladeshBarbadosBelarusBelgiumBelizeBeninBermudaBhutanBolivia, Plurinational State ofBonaire, Sint Eustatius and SabaBosnia and HerzegovinaBotswanaBouvet IslandBrazilBritish Indian Ocean TerritoryBrunei DarussalamBulgariaBurkina FasoBurundiCambodiaCameroonCanadaCape VerdeCayman IslandsCentral African RepublicChadChileChinaChristmas IslandCocos (Keeling) IslandsColombiaComorosCongoCongo, The Democratic Republic of theCook IslandsCosta RicaCote D’IvoireCroatiaCubaCuraçaoCyprusCzech RepublicDenmarkDjiboutiDominicaDominican RepublicEcuadorEgyptEl SalvadorEquatorial GuineaEritreaEstoniaEthiopiaFalkland Islands (Malvinas)Faroe IslandsFijiFinlandFranceFrench GuianaFrench PolynesiaFrench Southern TerritoriesGabonGambiaGeorgiaGermanyGhanaGibraltarGreeceGreenlandGrenadaGuadeloupeGuatemalaGuernseyGuineaGuinea-BissauGuyanaHaitiHeard Island and Mcdonald IslandsHoly See (Vatican City State)HondurasHong KongHungaryIcelandIndiaIndonesiaIran, Islamic Republic ofIraqIrelandIsle of ManIsraelItalyJamaicaJapanJerseyJordanKazakhstanKenyaKiribatiKorea, Democratic People’s Republic ofKorea, Republic ofKuwaitKyrgyzstanLao People’s Democratic RepublicLatviaLebanonLesothoLiberiaLibyan Arab JamahiriyaLiechtensteinLithuaniaLuxembourgMacaoMacedonia, The Former Yugoslav Republic ofMadagascarMalawiMalaysiaMaldivesMaliMaltaMartiniqueMauritaniaMauritiusMayotteMexicoMoldova, Republic ofMonacoMongoliaMontenegroMontserratMoroccoMozambiqueMyanmarNamibiaNauruNepalNetherlandsNew CaledoniaNew ZealandNicaraguaNigerNigeriaNiueNorfolk IslandNorwayOmanPakistanPalestinianPanamaPapua New GuineaParaguayPeruPhilippinesPitcairnPolandPortugalQatarReunionRomaniaRussian FederationRWANDASaint Barthélemy Saint Helena, Ascension and Tristan da CunhaSaint Kitts and NevisSaint LuciaSaint Martin (French part)Saint Pierre and MiquelonSaint Vincent and the GrenadinesSamoaSan MarinoSao Tome and PrincipeSaudi ArabiaSenegalSerbiaSeychellesSierra LeoneSingaporeSint Maarten (Dutch part)SlovakiaSloveniaSolomon IslandsSomaliaSouth AfricaSouth Georgia and the South Sandwich IslandsSouth SudanSpainSri LankaSudanSurinameSvalbard and Jan MayenSwazilandSwedenSwitzerlandSyrian Arab RepublicTaiwanTajikistanTanzania, United Republic ofThailandTimor-LesteTogoTokelauTongaTrinidad and TobagoTunisiaTurkeyTurkmenistanTurks and Caicos IslandsTuvaluUgandaUkraineUnited Arab EmiratesUnited KingdomUnited StatesUruguayUzbekistanVanuatuVenezuela, Bolivarian Republic ofVietnamVirgin Islands, BritishWallis and FutunaWestern SaharaYemenZambiaZimbabweI also wish to receive emails from AAAS/Science and Science advertisers, including information on products, services and special offers which may include but are not limited to news, careers information & upcoming events.Required fields are included by an asterisk(*)Under the rule, manufacturers would have to submit a range of data regarding the nanoscale substances they now make and that fall under TSCA’s scope—such as substances used in industrial applications. EPA wants to know how much the company is producing, for example, as well as potential public exposures, and manufacturing and processing methods. It also wants see any existing health and safety data. In addition, the agency would require manufacturers of proposed new nanomaterials to submit existing data before they want to start making and selling those substances.The rule wouldn’t force companies to generate any new health and safety data. And by itself, the rule wouldn’t restrict any nanomaterials’ use, EPA notes in its draft proposal. The agency’s actions “do not conclude and are not intended to conclude that nanoscale materials as a class, or specific uses of nanoscale materials, necessarily give rise to or are likely to cause harm,” the notice states. Rather, EPA says the information would let it better assess nanomaterials’ risks.And the agency states that its approach would help protect human health and the environment “without prejudging new technologies or creating unnecessary barriers to trade or hampering innovation.” EPA argues that case-by-case approach would jibe with a set of nanotech regulation principles released in 2011 by the White House Office of Science and Technology Policy. Those principles advise agencies against making one-size-fits-all judgments.The American Chemistry Council (ACC), the largest chemical industry trade group, is still evaluating the proposal, it said in a statement. But it “is particularly interested in how EPA defines the materials to be covered by the proposed rule,” says Jay West, manager of ACC’s Nanotechnology Panel, says in the statement.The proposal is “logical” and “creatively written,” says Lynn Bergeson, a managing partner with the law firm Bergeson & Campbell, P.C. in Washington, D.C., which advises companies on EPA regulatory compliance. Some companies may argue the rule is too broad or burdensome, she says, or worry that EPA’s move could stigmatize their products. But the government effort to collect information could potentially help the industry by reassuring a skeptical public, she adds. “If there are no data on which EPA is able to rely to conclude that there is no risk, then the agency really is not doing its job,” she says.The proposal is a good first step for EPA, says Jaydee Hanson, policy director at the International Center for Technology Assessment, a group in Washington, D.C., that has raised concerns about nanotechnology’s potential risks. But he worries that many companies might simply not respond and that the cash-strapped EPA would struggle to crack down on violators. And he worries that the proposal would let companies keep too much information secret, by claiming it as confidential business information. (TSCA reforms that Congress is debating would limit the types of information that companies could claim as confidential, he notes.) But Hanson is looking on the bright side. “We wish [EPA was] doing more, but we’re excited that they are doing it,” he says.Still, even with all the new information in hand, it’s unclear how much action EPA could take to restrict nanomaterials under current law. In general, EPA has moved slowly to regulate new chemicals, and struggled to meet the burden that TSCA sets on it for removing, restricting, or preventing the sale of chemicals found to be unsafe. Congress says it wants to make that process easier, but it is unclear how any new rules would apply to nanotechnologies.