[Code of Federal Regulations] [Title 40, Volume 31] [Revised as of July 1, 2006] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR799.5085] [Page 275-282] TITLE 40--PROTECTION OF ENVIRONMENT CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PART 799_IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS--Table of Contents Subpart D_Multichemical Test Rules Sec. 799.5085 Chemical testing requirements for certain high production volume chemicals. (a) What substances will be tested under this section? Table 2 in paragraph (j) of this section identifies the chemical substances that must be tested under this section. For the chemical substances identified as ``Class 1'' substances in Table 2 in paragraph (j) of this section, the purity of each chemical substance must be 99% or greater, except for 1,3-propanediol, 2,2-bis[(nitrooxy)methyl]-, dinitrate (ester) (CAS No. 78-11-5), also known as pentaerythritol tetranitrate (PETN). PETN cannot be tested at 99% purity because of its explosive properties. It must be diluted in water or tested as a stabilized mixture with an appropriate stabilizer (e.g., D-lactose monohydrate is the stabilizer in PETN, NF which is a mixture of 20% by weight PETN and 80% by weight D-lactose monohydrate). The stabilizer used must be tested as a control. For the chemical substances identified as ``Class 2'' substances in Table 2 in paragraph (j), a representative form of each chemical substance must be tested. The representative form selected for a given Class 2 chemical substance should meet industry or consensus standards where they exist. (b) Am I subject to this section? (1) If you manufacture (including import) or intend to manufacture, or process or intend to process, any chemical substance listed in Table 2 in paragraph (j) of this section at any time from April 17, 2006 to the end of the test data reimbursement period as defined in 40 CFR 791.3(h), you are subject to this section with respect to that chemical substance. (2) If you do not know or cannot reasonably ascertain that you manufacture or process a chemical substance listed in Table 2 in paragraph (j) of this section during the time period described in paragraph (b)(1) of this section (based on all information in your possession or control, as well as all information that a reasonable person similarly situated might be expected to possess, control, or know, or could obtain without an unreasonable burden), you are not subject to this section with respect to that chemical substance. (c) If I am subject to this section, when must I comply with it? (1)(i) Persons subject to this section are divided into two groups, as set forth in Table 1 of this paragraph: Tier 1 (persons initially required to comply) and Tier 2 (persons not initially required to comply). If you are subject to this section, you must determine if you fall within Tier 1 or Tier 2, based on Table 1 of this paragraph. [[Page 276]] Table 1--Persons Subject to the Rule: Persons in Tier 1 and Tier 2 ------------------------------------------------------------------------ Persons not initially required Persons initially required to comply to comply with this section with this section (Tier 1) (Tier 2) ------------------------------------------------------------------------ Persons not otherwise specified in A. Persons who manufacture (as column 2 of this table that defined at TSCA section 3(7)) manufacture (as defined at TSCA or intend to manufacture a section 3(7)) or intend to manufacture chemical substance included in a chemical substance included in this this section solely as one or section. more of the following: --As a byproduct (as defined at 40 CFR 791.3(c)); --As an impurity (as defined at 40 CFR 790.3); --As a naturally occurring substance (as defined at 40 CFR 710.4(b)); --As a non-isolated intermediate (as defined at 40 CFR 704.3); --As a component of a Class 2 substance (as described at 40 CFR 720.45(a)(1)(i)); --In amounts of less than 500 kg (1,100 lbs.) annually (as described at 40 CFR 790.42(a)(4)); or --For R & D (as described at 40 CFR 790.42(a)(5)). B. Persons who process (as defined at TSCA section 3(10)) or intend to process a chemical substance included in this section (see 40 CFR 790.42(a)(2)). ------------------------------------------------------------------------ (ii) Table 1 of paragraph (c)(1)(i) of this section expands the list of persons specified in Sec. 790.42(a)(2), (a)(4), and (a)(5) of this chapter, who, while legally subject to this section, must comply with the requirements of this section only if directed to do so by EPA under the circumstances set forth in paragraphs (c)(5) and (c)(8) of this section. (2) If you are in Tier 1 with respect to a chemical substance listed in Table 2 in paragraph (j) of this section, you must, for each test required under this section for that chemical substance, either submit to EPA a letter of intent to test or apply to EPA for an exemption from testing. The letter of intent to test or the exemption application must be received by EPA no later than May 15, 2006. (3) If you are in Tier 2 with respect to a chemical substance listed in Table 2 in paragraph (j) of this section, you are considered to have an automatic conditional exemption and you will be required to comply with this section with regard to that chemical substance only if directed to do so by EPA under paragraphs (c)(5) or (c)(8) of this section. (4) If no person in Tier 1 has notified EPA of its intent to conduct one or more of the tests required by this section on any chemical substance listed in Table 2 in paragraph (j) of this section by May 15, 2006, EPA will publish a Federal Register document that will specify the test(s) and the chemical substance(s) for which no letter of intent has been submitted, and notify manufacturers and processors in Tier 2 of their obligation to submit a letter of intent to test or to apply for an exemption from testing. (5) If you are in Tier 2 with respect to a chemical substance listed in Table 2 in paragraph (j) of this section, and if you manufacture or process this chemical substance as of April 17, 2006, or within 30 days after publication of the Federal Register document described in paragraph (c)(4) of this section, you must, for each test specified for that chemical substance in the document described in paragraph (c)(4) of this section, either submit to EPA a letter of intent to test or apply to EPA for an exemption from testing. The letter of intent to test or the exemption application must be received by EPA no later than 30 days after publication of the document described in paragraph (c)(4) of this section. (6) If no manufacturer or processor has notified EPA of its intent to conduct one or more of the tests required by this section for any of the chemical substances listed in Table 2 in paragraph (j) of this section within 30 days after the publication of the Federal Register document described in paragraph (c)(4) of this section, EPA will notify all manufacturers and processors of those chemical substances of this fact by certified letter or by publishing a Federal Register document specifying the test(s) for which no letter of intent has been submitted. This letter or Federal Register document will additionally notify all manufacturers and processors that all exemption applications concerning the test(s) have been denied, and will give the manufacturers and processors of the chemical substance(s) an opportunity to take corrective action. (7) If no manufacturer or processor has notified EPA of its intent to conduct one or more of the tests required [[Page 277]] by this section for any of the chemical substances listed in Table 2 in paragraph (j) of this section within 30 days after receipt of the certified letter or publication of the Federal Register document described in paragraph (c)(6) of this section, all manufacturers and processors subject to this section with respect to that chemical substance who are not already in violation of this section will be in violation of this section. (8) If a problem occurs with the initiation, conduct, or completion of the required testing or the submission of the required data with respect to a chemical substance listed in Table 2 in paragraph (j) of this section, under the procedures in Sec. Sec. 790.93 and 790.97 of this chapter, EPA may initiate termination proceedings for all testing exemptions with respect to that chemical substance and may notify persons in Tier 1 and Tier 2 that they are required to submit letters of intent to test or exemption applications within a specified period of time. (9) If you are required to comply with this section, but your manufacturing or processing of a chemical substance listed in Table 2 in paragraph (j) of this section begins after the applicable compliance date referred to in paragraphs (c)(2), (c)(5), or (c)(8) of this section, you must either submit a letter of intent to test or apply to EPA for an exemption. The letter of intent to test or the exemption application must be received by EPA no later than the day you begin manufacturing or processing. (d) What must I do to comply with this section? (1) To comply with this section you must either submit to EPA a letter of intent to test, or apply to and obtain from EPA an exemption from testing. (2) For each test with respect to which you submit to EPA a letter of intent to test, you must conduct the testing specified in paragraph (h) of this section and submit the test data to EPA. (3) You must also comply with the procedures governing test rule requirements in part 790 of this chapter, as modified by this section, including the submission of letters of intent to test or exemption applications, the conduct of testing, and the submission of data; Part 792--Good Laboratory Practice Standards of this chapter; and this section. The following provisions of 40 CFR part 790 do not apply to this section: Paragraphs (a), (d), (e), and (f) of Sec. 790.45; paragraph (a)(2) and paragraph (b) of Sec. Sec. 790.80; 790.82(e)(1); 790.85; and 790.48. (e) If I do not comply with this section, when will I be considered in violation of it? You will be considered in violation of this section as of 1 day after the date by which you are required to comply with this section. (f) How are EPA's data reimbursement procedures affected for purposes of this section? If persons subject to this section are unable to agree on the amount or method of reimbursement for test data development for one or more chemical substances included in this section, any person may request a hearing as described in 40 CFR part 791. In the determination of fair reimbursement shares under this section, if the hearing officer chooses to use a formula based on production volume, the total production volume amount will include amounts of a chemical substance produced as an impurity. (g) Who must comply with the export notification requirements? Any person who exports, or intends to export, a chemical substance listed in Table 2 in paragraph (j) of this section is subject to part 707, subpart D, of this chapter. (h) How must I conduct my testing? (1) The tests that are required for each chemical substance are indicated in Table 2 in paragraph (j) of this section. The test methods that must be followed are provided in Table 3 in paragraph (j) of this section. You must proceed in accordance with these test methods as required according to Table 3 in paragraph (j) of this section, or as appropriate if more than one alternative is allowed according to Table 3 in paragraph (j) of this section. Included in Table 3 in paragraph (j) of this section are the following 11 methods which are incorporated by reference: (i) Standard Test Method for Relative Initial and Final Melting Points and the Melting Range of Organic Chemicals, ASTM E 324-99. (ii) Standard Test Method for Partition Coefficient (N-Octanol/ Water) Estimation by Liquid Chromatography, ASTM E 1147-92. (Reapproved 1997) [[Page 278]] (iii) Standard Guide for Conducting Acute Toxicity Tests on Test Materials with Fishes, Macroinvertebrates, and Amphibians, ASTM E 729- 96. (Reapproved 2002) (iv) Standard Test Method for Measurements of Aqueous Solubility, ASTM E 1148-02. (v) Standard Test Method for Estimating Acute Oral Toxicity in Rats, ASTM E 1163-98. (Reapproved 2002) (vi) Standard Guide for Conducting Daphnia Magna Life-Cycle Toxicity Tests, ASTM E 1193-97. (Reapproved 2004) (vii) Standard Guide for Conducting Static Toxicity Tests with Microalgae, ASTM E 1218-04. (viii) Standard Test Method for Determining Biodegradability of Organic Chemicals in Semi-Continuous Activated Sludge (SCAS), ASTM E 1625-94. (Reapproved 2001) (ix) Standard Test Method for Vapor Pressure of Liquids by Ebulliometry, ASTM E 1719-97. (x) Standard Test Method for Determining Vapor Pressure by Thermal Analysis, ASTM E 1782-03. (xi) Water Quality--Evaluation of Ultimate Aerobic Biodegradability of Organic Compounds in Aqueous Medium--Static Test (Zahn-Wellens Method), Second Edition, June 1, 1999, ISO 9888-99. (2) The Director of the Federal Register approved this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain copies of the ASTM guidelines from the American Society for Testing and Materials, 100 Bar Harbor Dr., West Conshohocken, PA 19428- 2959, and a copy of the ISO guideline from the International Organization for Standardization, Case Postale, 56 CH-1211 Geneve 20 Switzerland. You may inspect each test method at the EPA Docket Center, EPA West, Rm. B102, 1301 Constitution Ave., NW., Washington, DC or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal--register/code--of--federal-- regulations/ibr--locations.html. (i) Reporting requirements. A final report for each specific test for each subject chemical substance must be received by EPA by May 17, 2007, unless an extension is granted in writing pursuant to 40 CFR 790.55. A robust summary of the final report for each specific test should be submitted in addition to and at the same time as the final report. The term ``robust summary'' is used to describe the technical information necessary to adequately describe an experiment or study and includes the objectives, methods, results, and conclusions of the full study report which can be either an experiment or in some cases an estimation or prediction method. Guidance for the compilation of robust summaries is described in a document entitled Draft Guidance on Developing Robust Summaries which is available at: http://www.epa.gov/ chemrtk/robsumgd.htm. (j) Designation of specific chemical substances and testing requirements. The chemical substances identified by chemical name, Chemical Abstract Service Number (CAS No.), and class in Table 2 of this paragraph must be tested in accordance with the requirements designated in Tables 2 and 3 of this paragraph, and the requirements described in 40 CFR Part 792--Good Laboratory Practice Standards: Table 2--Chemical Substances And Testing Requirements ---------------------------------------------------------------------------------------------------------------- Required tests/(See Table 3 CAS No. Chemical name Class of this section) ---------------------------------------------------------------------------------------------------------------- 74-95-3 Methane, dibromo- 1 A, C1, E2, F2 ---------------------------------------------------------------------------------------------------------------- 75-36-5 Acetyl chloride 1 A, B, C2, E2, F1 ---------------------------------------------------------------------------------------------------------------- 78-11-5 1,3-Propanediol, 2,2- 1 A4, A5, B, C6, F2 bis[(nitrooxy)methyl]-, dinitrate (ester) ---------------------------------------------------------------------------------------------------------------- 84-65-1 9,10-Anthracenedione 1 A, F2 ---------------------------------------------------------------------------------------------------------------- 108-19-0 Imidodicarbonic diamide 1 A, B, C1, D, E1, E2, F1 ---------------------------------------------------------------------------------------------------------------- [[Page 279]] 110-44-1 2,4-Hexadienoic acid, 1 A, C4 (2E,4E)- ---------------------------------------------------------------------------------------------------------------- 112-52-7 Dodecane, 1-chloro 1 A, B, C3, D, E1, E2, F1 ---------------------------------------------------------------------------------------------------------------- 118-82-1 Phenol, 4,4'- 1 A, B, D, E1, E2, F2 methylenebis[2,6-bis(1,1- dimethylethyl)]- ---------------------------------------------------------------------------------------------------------------- 149-44-0 Methanesulfinic acid, 1 A, B, C1, E2, F1 hydroxy-, monosodium salt ---------------------------------------------------------------------------------------------------------------- 409-02-9 Heptenone, methyl- 2 A, B, C1, D, E1, E2, F1 ---------------------------------------------------------------------------------------------------------------- 594-42-3 Methanesulfenyl chloride, 1 A, B, C1, E1, E2, F2 trichloro- ---------------------------------------------------------------------------------------------------------------- 624-83-9 Methane, isocyanato- 1 A, C1 ---------------------------------------------------------------------------------------------------------------- 1324-76-1 Benzenesulfonic acid, [[4- 2 A, B, C1, D, E1, E2, F1 [[4-(phenylamino)phenyl][4- (phenylimino)-2,5- cyclohexadien-1- ylidene]methyl]phenyl]amino ]- ---------------------------------------------------------------------------------------------------------------- 2941-64-2 Carbonochloridothioic acid, 1 A, B, C1, E2, F1 S-ethyl ester ---------------------------------------------------------------------------------------------------------------- 8005-02-5 C.I. Solvent Black 7 2 A, B, C1, D, E2, F1 ---------------------------------------------------------------------------------------------------------------- 65996-78-3 Light oil (coal), coke-oven 2 A, B, C1, D, E1, E2, F1 ---------------------------------------------------------------------------------------------------------------- 68611-64-3 Urea, reaction products with 2 A, B, C1, D, E1, E2, F1 formaldehyde ---------------------------------------------------------------------------------------------------------------- Table 3--Key to the Test Requirements Denoted by Alphanumeric Symbols in Table 2 of This Paragraph ---------------------------------------------------------------------------------------------------------------- Test requirements and Testing category Test symbol references Special conditions ---------------------------------------------------------------------------------------------------------------- Physical/chemical properties A 1. Melting Point: ASTM n-Octanol/water E 324 (capillary tube) Partition Coefficient 2. Boiling Point: ASTM or log Kow: E 1719 (ebulliometry). Which method is 3. Vapor Pressure: ASTM required, if any, is E 1782 (thermal determined by the test analysis). substance's 4. n-Octanol/Water estimated\1\ log Kow Partition Coefficient as follows: (log 10 basis) or log log Kow <0: no testing Kow: (See special required. conditions for the log log Kow range 0-1: Kow test requirement Method A or B. and select the log Kow range >1-4: appropriate method to Method A or B or C. use, if any, from log Kow range >4-6: those listed in this Method B or C. column.). log Kow >6: Method C. Method A: 40 CFR Test sponsors are 799.6755 (shake flask). required to provide in Method B: ASTM E 1147 the final study report (liquid the underlying chromatography). rationale for the Method C: 40 CFR method selected. In 799.6756 (generator order to ensure column). environmental 5. Water Solubility: relevance, EPA highly (See special recommends that the conditions for the selected study be water solubility test conducted at pH 7. requirement and select Water Solubility: the appropriate method Which method is to use, if any, from required, if any, is those listed in this determined by the test column.). substance's Method A: ASTM E 1148 estimated\2\ water (shake flask). solubility. Test Method B: 40 CFR sponsors are required 799.6784 (shake flask). to provide in the Method C: 40 CFR final study report the 799.6784 (column underlying rationale elution). for the method Method D: 40 CFR selected. In order to 799.6786 (generator ensure environmental column). relevance, EPA highly recommends that the selected study be conducted at pH 7. 5,000 mg/L: Method A or B. 10 mg/L -- 5,000 mg/L: Method A, B, C, or D. 0.001 mg/L-- 10 mg/L: Method C or D. <=0.001 mg/L: No testing required. ---------------------------------------------------------------------------------------------------------------- Environmental fate and pathways-- B For B, choose either of None Inherent biodegradation the methods listed in this column: 1. ASTM 1625 (semicontinuous activated sludge test) OR. 2. ISO 9888 (Zahn- Wellens method). ---------------------------------------------------------------------------------------------------------------- [[Page 280]] Aquatic toxicity C1 For C1, Test Group 1 or The following are the Test Group 2 listed in special conditions for this column must be C1, C2, C3, C4, C5, used to fulfill the and C7 testing; there testing requirements-- are no special See special conditions for C6. conditions. If log Kow <4.2: Test Test Group 1 for C1:... Group 1 is required 1. Acute Toxicity to If log Kow >= 4.2: Test Fish: ASTM E 729. Group 2 is required 2. Acute Toxicity to Which test group is Daphnia: ASTM E 729. required is determined 3. Toxicity to Plants by the test (Algae): ASTM E 1218. substance's measured Test Group 2 for C1:... log Kow as obtained 1. Chronic Toxicity to under A\3\. Daphnia: ASTM E 1193. 2. Toxicity to Plants (Algae): ASTM E 1218. -------------------------------------------------- C2 For C2, Test Group 1 or Test Group 2 listed in this column must be used to fulfill the testing requirements-- See special conditions. Test Group 1 for C2:... 1. Acute Toxicity to Daphnia: ASTM E 729. 2. Toxicity to Plants (Algae): ASTM E 1218. Test Group 2 for C2:... 1. Chronic Toxicity to Daphnia: ASTM E 1193. 2. Toxicity to Plants (Algae): ASTM E 1218. -------------------------------------------------- C3 For C3, Test Group 1 or Test Group 2 listed in this column must be used to fulfill the testing requirements-- See special conditions. Test Group 1 for C3:... 1. Acute Toxicity to Fish: ASTM E 729. 2. Toxicity to Plants (Algae): ASTM E 1218. Test Group 2 for C3:... 1. Chronic Toxicity to Daphnia: ASTM E 1193. 2. Toxicity to Plants (Algae): ASTM E 1218. -------------------------------------------------- C4 For C4, Test Group 1 or Test Group 2 listed in this column must be used to fulfill the testing requirements-- See special conditions. Test Group 1 for C4:... 1. Acute Toxicity to Fish: ASTM E 729. 2. Acute Toxicity to Daphnia: ASTM E 729. Test Group 2 for C4:... 1. Chronic Toxicity to Daphnia: ASTM E 1193. -------------------------------------------------- C5 For C5, Test Group 1 or Test Group 2 below must be used to fulfill the testing requirements--See special conditions. Test Group 1 for C5:... 1. Acute Toxicity to Daphnia: ASTM E 729. Test Group 2 for C5:... 1. Chronic Toxicity to Daphnia: ASTM E 1193. -------------------------------------------------- C6 Toxicity to Plants (Algae): ASTM E 1218 -------------------------------------------------- C7 For C7, Test Group 1 or ....................... Test Group 2 of this column must be used to fulfill the testing requirements--See special conditions. Test Group 1 for C7:... 1. Acute Toxicity to Fish: ASTM E 729. Test Group 2 for C7:... 1. Chronic Toxicity to Daphnia: ASTM E 1193. ---------------------------------------------------------------------------------------------------------------- [[Page 281]] Mammalian toxicity--Acute D See special conditions Which testing method is for this test required is determined requirement and select by the test the method that must substance's physical be used from those state at room listed in this column. temperature (25 Method A: Acute [deg]C). For those Inhalation Toxicity test substances that (rat): 40 CFR 799.9130. are gases at room Method B: EITHER:...... temperature, Method A 1. Acute (Up/Down) Oral is required; Toxicity (rat): ASTM E otherwise, use either 1163 OR. of the two methods 2. Acute (Up/Down) listed under Method B. Oral Toxicity (rat): In Method B, 40 CFR 40 CFR 799.9110(d)(1)(i)(A) 799.9110(d)(1)(i)(A). refers to the OECD 425 Up/Down Procedure\4\. Estimating starting dose for Method B: Data from the neutral red uptake basal cytotoxicity assay\5\ using normal human keratinocytes or mouse BALB/c 3T3 cells may be used to estimate the starting dose. ---------------------------------------------------------------------------------------------------------------- Mammalian toxicity--Genotoxicity E1 Bacterial Reverse None Mutation Test (in vitro): 40 CFR 799.9510 -------------------------------------------------------------------------- E2 Conduct any one of the Persons required to following three tests conduct testing for for chromosomal chromosomal damage are damage: encouraged to use the In vitro Mammalian in vitro Mammalian Chromosome Aberration Chromosome Aberration Test: 40 CFR 799.9537 Test (40 CFR 799.9537) OR. to generate the needed Mammalian Bone Marrow data unless known Chromosomal Aberration chemical properties Test (in vivo in (e.g., physical/ rodents: mouse chemical properties, (preferred species), chemical class rat, or Chinese characteristics) hamster): 40 CFR preclude its use. A 799.9538 OR. subject person who Mammalian Erythrocyte uses one of the in Micronucleus Test vivo methods instead [sampled in bone of the in vitro method marrow] (in vivo in to address a rodents: Mouse chromosomal damage (preferred species), test requirement must rat, or Chinese submit to EPA a hamster): 40 CFR rationale for 799.9539. conducting that alternate test in the final study report. -------------------------------------------------------------------------- Mammalian toxicity--Repeated dose/ F1 Combined Repeated Dose Where F1 is required, reproduction/ developmental Toxicity Study with EPA recommends use of the Reproduction/ the Combined Repeated Developmental Toxicity Dose Toxicity Study Screening Test: 40 CFR with the Reproduction/ 799.9365 OR Developmental Toxicity Reproduction/ Screening Test (40 CFR Developmental Toxicity 799.9365). However, Screening Test: 40 CFR there may be valid 799.9355 AND. reasons to test a Repeated Dose 28-Day particular chemical Oral Toxicity Study in using both 40 CFR rodents: 40 CFR 799.9355 and 40 CFR 799.9305. 799.9305 to fill Mammalian Toxicity-- Repeated Dose/ Reproduction/ Developmental data needs. A subject person who uses the combination of 40 CFR 799.9355 and 40 CFR 799.9305 in place of 40 CFR 799.9365 must submit to EPA a rationale for conducting these alternate tests in the final study reports. Where F2 or F3 is required, no rationale for conducting the required test need be provided in the final study report. -------------------------------------------------- F2 Reproduction/ Developmental Toxicity Screening Test: 40 CFR 799.9355 -------------------------------------------------- F3 Repeated Dose 28-Day Oral Toxicity Study in rodents: 40 CFR 799.9305 ---------------------------------------------------------------------------------------------------------------- \1\ EPA recommends, but does not require, that log Kow be quantitatively estimated prior to initiating this study. One method, among many similar methods, for estimating log Kow is described in the article entitled Atom/Fragment Contribution Method for Estimating Octanol-Water Partition Coefficients) by W.M. Meylan and P.H. Howard in the Journal of Pharmaceutical Sciences. 84(1):83-92. January 1992. This reference is available under docket ID number EPA-HQ-OPPT-2005-0033 at the EPA Docket Center, Rm. B102, 1301 Constitution Ave., NW., Washington, DC, from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. \2\ EPA recommends, but does not require, that water solubility be quantitatively estimated prior to initiating this study. One method, among many similar methods, for estimating water solubility is described in the article entitled Improved Method for Estimating Water Solubility From Octanol/Water Partition Coefficient by W.M. Meylan, P.H. Howard, and R.S. Boethling in Environmental Toxicology and Chemistry. 15(2):100-106. 1996. This reference is available under docket ID number EPA-HQ-OPPT-2005-0033 at the EPA Docket Center, Rm. B102, 1301 Constitution Ave., NW., Washington, DC, from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. \3\ Chemical substances that are dispersible in water may have log Kow values greater than 4.2 and may still be acutely toxic to aquatic organisms. EPA recommends, but does not require, that test sponsors who wish to conduct Test Group 1 studies on such chemicals to submit to EPA for approval a written request to conduct Test Group 1 studies 90 days prior to conducting such studies. The written request should include the rationale for conducting Test Group 1 studies. [[Page 282]] \4\ The OECD 425 Up/Down Procedure, revised by OECD in December 2001, is available under docket ID number EPA-HQ- OPPT-2005-0033 at the EPA Docket Center, Rm. B102, 1301 Constitution Ave., NW., Washington, DC, from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. \5\ The neutral red uptake basal cytotoxicity assay, which may be used to estimate the starting dose for the mammalian toxicity-acute endpoint, is available under docket ID number EPA-HQ-OPPT-2005-0033 at the EPA Docket Center, Rm. B102, 1301 Constitution Ave., NW., Washington, DC, from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. (k) Effective date. This section is effective on April 17, 2006. [71 FR 13730, Mar. 16, 2006]