[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: 40CFR799.2700]
[Page 254-258]
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 B_Specific Chemical Test Rules
Sec. 799.2700 Methyl ethyl ketoxime.
(a) Identification of test substance. (1) Methyl ethyl ketoxime
(MEKO, CAS No. 96-29-7) shall be tested in accordance with this section.
(2) MEKO of at least 99 percent purity shall be used as the test
substance.
(b) Persons required to submit study plans, conduct tests, and
submit data. All persons who manufacture (including import) or process
or intend to manufacture or process MEKO, including persons who
manufacture or process or intend to manufacture or process
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MEKO as a byproduct, or who import or intend to import products which
contain MEKO, after the date specified in paragraph (e) of this section
to the end of the reimbursement period, shall submit letters of intent
to conduct testing, submit study plans, conduct tests and submit data,
or submit exemption applications, as specified in this section, subpart
A of this part, and parts 790 and 792 of this chapter for single-phase
rulemaking. Persons who manufacture, import, or process MEKO only as an
impurity are not subject to these requirements.
(c) Health effects testing--(1) Pharmacokinetics testing--(i)
Required testing. Pharmacokinetics testing shall be conducted with MEKO
in accordance with paragraph (c)(1)(ii) of this section.
(ii) [Reserved]
(2) Oncogenicity--(i) Required testing. Oncogenicity testing shall
be conducted in accordance with Sec. 798.3300 of this chapter.
(ii) Route of administration. MEKO shall be administered either
orally or by inhalation.
(iii) Reporting requirements. (A) Oncogenicity testing shall be
completed and a final report submitted to EPA within 53 months of the
date specified in paragraph (e) of this section.
(B) Interim progress reports shall be submitted to EPA at 6-month
intervals, beginning 6 months after the date specified in paragraph (e)
of this section, until submission of the final report to EPA.
(3) Developmental toxicity--(i) Required testing. Developmental
toxicity testing shall be conducted in a rodent and a nonrodent
mammalian species in accordance with Sec. 798.4900 of this chapter.
(ii) Route of administration. MEKO shall be administered orally.
(iii) Reporting requirements. (A) Developmental toxicity testing
shall be completed and a final report submitted to EPA within 15 months
of the date specified in paragraph (e) of this section.
(B) Interim progress reports shall be submitted to EPA at 6-month
intervals, beginning 6 months after the date specified in paragraph (e)
of this section.
(4) Reproductive toxicity--(i) Required testing. (A) Reproductive
toxicity testing shall be conducted orally in accordance with Sec.
798.4700 of this chapter except for the provisions in paragraphs (c)
(8)(iii) and (9)(i) of Sec. 798.4700.
(B) For the purpose of this section, the following provisions also
apply:
(1) The following organs and tissues, or representative samples
thereof, shall be preserved in a suitable medium for possible future
histopathological examination: Vagina, uterus, oviducts, ovaries,
testes, epididymides, vas deferens, seminal vesicles, prostate,
pituitary gland, and, target organ(s) of all P and F1 animals
selected for mating.
(2)(i) Full histopathology shall be conducted on the organs and
tissues listed in paragraph (c)(4)(i)(B)(1) of this section for all high
dose and control P and F1 animals selected for mating.
(ii) The integrity of the various cell stages of spermatogenesis
shall be determined, with particular attention directed toward achieving
optimal quality in the fixation and embedding. Preparations of
testicular and associated reproductive organ samples for histology
should follow the recommendations of Lamb and Chapin (1985) under
paragraph (d)(1) of this section, or an equivalent procedure.
Histopathology of the testes shall be conducted on all P and
F1 adult males at the time of sacrifice, and histological
analyses shall include evaluations of the spermatogenic cycle, i.e., the
presence and integrity of the 14 cell stages. These evaluations should
follow the guidance provided by Clermont and Percy (1957) under
paragraph (d)(2) of this section. Information shall also be provided
regarding the nature and level of lesions observed in control animals
for comparative purposes.
(iii) Data on female cyclicity shall be obtained by conducting
vaginal cytology in P and F1 females over the last 3 weeks
prior to mating; the cell staging technique of Sadleir (1978) and the
vaginal smear method in Hafez (1978) under paragraphs (d)(3) and (d)(7)
of this section, respectively, or equivalent methods should be used.
Data shall be provided on whether the animal is cycling and the cycle
length.
(iv) P and F1 females shall continue to be exposed to
MEKO for at least an additional 2 weeks following weaning of offspring
to permit them to begin cycling once again. They shall then be
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sacrificed and their ovaries shall be serially sectioned with a
sufficient number of sections examined to adequately detail oocyte and
follicular morphology. The methods of Mattison and Thorgiersson (1979)
and Pederson and Peters (1968) under paragraphs (d) (4) and (5) of this
section, respectively, may provide guidance. The strategy for sectioning
and evaluation is left to the discretion of the investigators, but shall
be described in detail in the study plan and final report. The nature
and background level of lesions in control tissue shall also be noted.
(v) Gross and histopathologic evaluations shall be conducted on the
mammary glands in F1 females and F2 pups
sacrificed at weaning and in adult F1 females at the
termination of the study. Any abnormalities shall be described in the
final report.
(ii) Reporting requirements. (A) Reproductive toxicity testing shall
be completed and a final report submitted to EPA within 29 months of the
date specified in paragraph (e) of this section.
(B) Interim progress reports shall be submitted to EPA at 6-month
intervals, beginning six months after the date specified in paragraph
(e) of this section until submission of the final report to EPA.
(5) Mutagenic effects--gene mutations--(i) Required testing. The
sex-linked recessive lethal assay in Drosophila shall be conducted with
MEKO in accordance with Sec. 798.5275 of this chapter.
(ii) Reporting requirements. (A) The sex-linked recessive lethal
assay in Drosophila shall be completed and a final report submitted to
EPA within 18 months of the date specified in paragraph (e) of this
section.
(B) Interim progress reports shall be submitted to EPA at 6-month
intervals beginning 6 months after the date specified in paragraph (e)
of this section.
(6) Mutagenic effects--chromosomal aberrations--(i) Required
testing. (A) An in vivo mammalian bone marrow cytogenetics test shall be
conducted with MEKO in accordance with either Sec. 798.5385
(chromosomal analysis) of this chapter, or Sec. 798.5395 (micronucleus
assay) of this chapter except for the provisions in paragraphs (d)(5)
(ii), (iii), and (iv) of Sec. Sec. 798.5385 and 798.5395.
(B) For the purpose of this section, the following provisions also
apply if Sec. 798.5385 of this chapter is used in conducting the test:
(1) Dose levels and duration of exposure. At least three dose levels
shall be tested. The highest dose tested shall be the maximum tolerated
dose or that dose producing some signs of cytotoxicity (e.g., partial
inhibition of mitosis) or shall be the highest dose attainable. Under
oral administration, animals shall be exposed once per day for 5
consecutive days. Under administration by inhalation, animals shall be
exposed 6 hours per day for 5 consecutive days.
(2) Route of administration. Animals shall be exposed to MEKO either
orally or by inhalation.
(C) For the purpose of this section, the following provisions also
apply if Sec. 798.5395 of this chapter is used in conducting the test:
(1) Dose levels and duration of exposure. At least three-dose levels
shall be tested. The highest dose tested shall be the maximum tolerated
dose or that dose producing some signs of cytotoxicity (e.g., a change
in the ratio of polychromatic to normochromatic erythrocytes) or shall
be the highest dose attainable. Under oral administration animals shall
be exposed once per day for 5 consecutive days. Under administration by
inhalation, animals shall be exposed 6 hours per day for 5 consecutive
days.
(2) Route of administration. Animals shall be exposed to MEKO either
orally or by inhalation.
(ii) Reporting requirements. (A) The oral in vivo mammalian
cytogenetics test shall be completed and a final report submitted to EPA
within 14 months of the date specified in paragraph (e) of this section.
The inhalation in vivo mammalian cytogenetics test shall be completed
and a final report submitted to EPA within 17 months of the date
specified in paragraph (e) of this section.
(B) Interim progress reports shall be submitted to EPA at 6-month
intervals, beginning 6 months after the date specified in paragraph (e)
of this section.
(7) Neurotoxicity--(i) Required testing--(A) Functional
observational battery. (1)
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A functional observational battery shall be conducted with MEKO in
accordance with Sec. 798.6050 of this chapter except for the provisions
in paragraphs (d) (4)(ii), (5), and (6) of Sec. 798.6050.
(2) For the purpose of this section, the following provisions also
apply:
(i) Route of exposure. Animals shall be exposed either orally or by
inhalation.
(ii) Lower doses. The data from the lower doses shall show either
graded dose-dependent effects in at least two of all the doses tested,
including the highest dose, or no neurotoxic (behavioral) effects at any
dose tested.
(iii) Duration and frequency of exposure. For the oral acute
testing, animals shall be exposed once. For the oral subchronic testing,
animals shall be exposed once per day 5 days per week for a 90-day
period. For the inhalation acute testing, animals shall be exposed for 6
hours for 1 day. For the inhalation subchronic testing, animals shall be
exposed 6 hours per day 5 days per week for a 90-day period.
(B) Motor activity. (1) A motor activity test shall be conducted
with MEKO in accordance with Sec. 798.6200 of this chapter except for
provisions in paragraphs (d) (4)(ii), (5), and (6) of Sec. 798.6200.
(2) For the purpose of this section, the following provisions also
apply:
(i) Route of exposure. Animals shall be exposed either orally or by
inhalation.
(ii) Lower doses. The data from the lower doses shall show either
graded dose-dependent effects in at least two of all the doses tested
including the highest dose, or no neurotoxic (behavioral) effects at any
dose tested.
(iii) Duration and frequency of exposure. For the acute oral
testing, animals shall be exposed once. For the oral subchronic testing,
animals shall be exposed once per day 5 days per week for a 90-day
period. For the acute inhalation testing, animals shall be exposed for 6
hours for 1 day. For the inhalation subchronic testing, the animals
shall be exposed for 6 hours per day 5 days per week for a 90-day
period.
(C) Neuropathology. (1) A neuropathology test shall be conducted
with MEKO in accordance with Sec. 798.6400 of this chapter except for
the provisions in paragraphs (d) (4)(ii), (5), (6), and (8)(iv)(C) of
Sec. 798.6400.
(2) For the purpose of this section, the following provisions also
apply:
(i) Route of exposure. Animals shall be exposed either orally or by
inhalation.
(ii) Lower doses. The data from the lower doses shall show either
graded dose-dependent effects in at least two of all the doses tested
including the highest dose, or no neurotoxic (behavioral) effects at any
dose tested.
(iii) Duration and frequency of exposure. Animals shall be exposed
orally once per day 5 days per week for a 90-day period; or if exposed
by inhalation, for 6 hours per day 5 days per week for a 90-day period.
(iv) Clearing and embedding. After dehydration, tissue specimens
shall be cleared with xylene and embedded in paraffin or paraplast
except for the sural nerve which should be embedded in plastic. Multiple
tissue specimens (e.g., brain, cord, ganglia) may be embedded together
in one single block for sectioning. All tissue blocks shall be labeled
to provide unequivocal identification. A suggested method for plastic
embedding is described by Spencer et al. in paragraph (d)(6) of this
section.
(ii) Reporting requirements. (A) The neurotoxicity tests required
under this paragraph (c)(7) and administered orally shall be completed
and the final results submitted to EPA within 18 months of the date
specified in paragraph (e) of this section. The neurotoxicity tests
required under this paragraph (c)(7) and administered by inhalation
shall be completed and the final results submitted to EPA within 21
months of the date specified in paragraph (e) of this section.
(B) Interim progress reports shall be submitted to EPA at 6-month
intervals beginning 6 months after the date specified in paragraph (e)
of this section until submission of the final report to EPA.
(d) References. For additional background information, the following
references should be consulted.
(1) Lamb, J. and Chapin, R.E. ``Experimental models of male
reproductive toxicology.'' In: ``Endocrine Toxicity.'' Thomas, J.A.,
Korach, K.S., and McLachlan, J.A., eds. New York, NY: Raven Press. pp.
85-115. (1985).
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(2) Clermont, Y. and Percey, B. ``Quantitative study of the cell
population of the seminiferous tubules in immature rats.'' ``American
Journal of Anatomy.'' 100:241-267. (1957).
(3) Sadleir, R.M.F.S. ``Cycles and seasons.'' In: ``Reproduction in
Mammals: I. Germ Cells and Fertilization.'' Austin, R. and Short R.V.,
eds. New York, NY: Cambridge Press. Chapter 4. (1978).
(4) Mattison, D.R. and Thorgiersson, S.S. ``Ovarian aryl hydrocarbon
hydroxylase activity and primordial oocyte toxicity of polycyclic
aromatic hydrocarbons in mice.'' ``Cancer Research.'' 39:3471-3475.
(1979).
(5) Pederson, T. and Peters, H. ``Proposal for classification of
oocytes and follicles in the mouse ovary.'' ``Journal of Reproduction
and Fertility.'' 17:555-557. (1968).
(6) Spencer, P.S., Bischoff, M., and Schaumburg, H.H.
``Neuropathological methods for the detection of neurotoxic disease.''
In: ``Experimental and Clinical Neurotoxicology.'' Spencer, P.S. and
Schaumburg, H.H., eds. Baltimore, MD: Williams and Wilkins, pp. 743-757
(1980).
(7) Hafez, E.S., ed., ``Reproduction and Breeding Techniques for
Laboratory Animals.'' Chapter 10. Philadelphia: Lea and Febiger. (1970).
(e) Effective dates. (1) The effective date of this final rule is
October 27, 1989.
(2) The guidelines and other test methods cited in this section are
referenced here as they exist on October 27, 1989.
[54 FR 37808, Sept. 13, 1989, as amended at 58 FR 34205, June 23, 1993]