4-Methyl-1-pentene was studied for oral toxicity in rats in a single dose toxicity test at doses of 300 and 2000 mg/kg, and in a repeat dose and reproductive/developmental toxicity test at doses of 0, 40, 200 and 1000 mg/kg/day.

With regard to the single dose toxicity, no female dosed at 300 or 2000 mg/kg died, and none showed any symptoms. 4-Methyl-1-pentene was therfore estimated to belong to category 5(>2000-50000 mg/kg) of the GHS.

With regard to repeat dose and reproductive/developmental toxicity, increase of urea nitrogen was observed at the end of the administration period, and increases of creatinine and chloride were observed at the end of the recovery period in females given 1000 mg/kg/day. Hyaline droplets and eosinophilic bodies in proximal tubular epithelium were observed in males given 200 mg/kg or more.

However no effects were observed on reproductive performance of parents or on developmental performance in the pups.

The NOAELs for systemic toxicity for parents are considered to be 40 mg/kg/day for males, 200 mg/kg/day for females, but for reproductive and developmental toxicity are considered to be 1000 mg/kg/day for parents and pups.

4-Methyl-1-pentene did not induce gene mutations in Salmonella typhimurium TA100, TA1535, TA98, TA1537 and Escherichia coli WP2 uvrA, with or without exogenous metabolic activation under the conditions of this study.

4-Methyl-1-pentene did not induce structural aberrations or polyploidy under the conditions of this study.

1. Single Dose Oral Toxicity 1)

Purity	:	98.36 %
Test species/strain	:	Rat/Crj:CD(SD)IGS
Test method	:	OECD Test Guideline 423
Route	:	Oral (gavage)
Dosage	:	300, 2000 mg/kg
Number of animals/group	:	Females, 3
Vehicle	:	Corn oil
GLP	:	Yes

　Test results:

No changes were observed after dosing at 300 and/or 2000 mg/kg.
4-Methyl-1-pentene was estimated to belong to category 5 (>2000-50000 mg/kg) of the GHS.

2. Repeated Dose and Reproductive/Developmental Toxicity 1)

Purity	:	98.36 %
Test species/strain	:	Rat/Crj:CD(SD)IGS
Test method	:	OECD Test Guideline 422
Route	:	Oral (gavage)
Dosage	:	0(vehicle), 40, 200, 1000 mg/kg
Number of animals/group	:	Males, 12; females, 12 Satellite females, 5
Vehicle	:	Corn oil
Administration period	:	Males and satellite females, 42 days Females, from 14 days before mating to day 5 of lactation
Terminal killing	:	Males and satellite females, days 43 or 57 Females, day 6 of lactation
GLP	:	Yes

　Test results:

In females, increase of urea nitrogen was apparent at 1000 mg/kg/day at the end of the administration period, and increases of creatinine and chloride were observed at the end of the recovery period. Hyaline droplets and eosinophilic bodies in the proximal tubular epithelium were observed in males given 200 mg/kg or more.

However, no effects were observed on reproductive performance of parents or on developmental performance in the pups.

The NOAELs for systemic toxicity for parents are considered to be 40 mg/kg/day for males, 200 mg/kg/day for females, but that for reproductive and developmental toxicity is considered to be 1000 mg/kg/day for parents and pups.

3. Genetic Toxicity

3-1. Bacterial test 1)

Purity	:	98.36 %
Test species/strains	:	Salmonella typhimurium TA100, TA1535, TA98, TA1537, Escherichia coli WP2 uvrA
Test method	:	Guidelines for Screening Mutagenicity Testing of Chemicals (Chemical Substances Control Law of Japan) and OECD Test Guideline 471
Procedures	:	Pre-incubation method
Solvent	:	Dimethyl sulfoxide
Positive controls	:	-S9 mix; 2-(2-Furyl)-3-(5-nitro-2-furyl) acrylamide (TA100, TA98, WP2 uvrA), sodium azide (TA1535) and 9-aminoacridine hydrochloride (TA1537) +S9 mix; 2-Aminoanthracene (all strains) [Dose-finding study]
Dosage	:	-S9 mix; 5, 15, 50, 150, 500, 1500, 5000 μg/plate (all strains) +S9 mix; 5, 15, 50, 150, 500, 1500, 5000 μg/plate (all strains) [Main study] -S9 mix; 46.9, 93.8, 188, 375, 750, 1500, 3000 μg/plate (all strains) +S9 mix; 46.9, 93.8, 188, 375, 750, 1500, 3000 μg/plate (all strains)
S9	:	Rat liver; induced with phenobarbital and 5,6-benzoflavone
Plates/test	:	3(1 for the dose-finding test)
Number of replicates	:	2(1 for the dose-finding test)
GLP	:	Yes

　Test results:

This chemical did not induce gene mutations in Salmonella typhimurium TA100, TA1535, TA98, TA1537 or Escherichia coli WP2 uvrA under the conditions of this study. Growth inhibition was observed at 750 μg/plate and above in TA1535, TA98 and TA1537, and at 1500 μg/plate and above in TA100 and WP2 uvrA, with and without S9 mix.

Genetic effects:

Salmonella typhimurium TA100, TA1535, TA98, TA1537

	+	?	-
Without metabolic activation:	[ ]	[ ]	[*]
With metabolic activation	[ ]	[ ]	[*]

Escherichia coli WP2 uvrA

	+	?	-
Without metabolic activation:	[ ]	[ ]	[*]
With metabolic activation	[ ]	[ ]	[*]

3-2. Non-bacterial in vitro test (chromosomal aberration test)1)

Purity	:	98.36 %
Type of cell used	:	Chinese hamster lung (CHL/IU) cells
Test method	:	Guidelines for Screening Mutagenicity Testing of Chemicals (Chemical Substances Control Law of Japan) and OECD Test Guideline 473
Solvent	:	Dimethyl sulfoxide
Positive controls	:	-S9 mix; Mitomycin C +S9 mix; Benzo[a]pyrene
Dosage	:	-S9 mix (short-term treatment); 98.6, 113, 130, 150 μg/mL +S9 mix (short-term treatment); 197, 227, 261 μg/mL -S9 mix (24 hr continuous treatment); 37.5, 56.3, 75.0, 85.8, 98.6, 113, 130, 150 μg/mL
S9	:	Rat liver, induced with phenobarbital and 5,6-benzoflavone
Plates/test	:	4(2: chromosome specimens, 2: measurement of growth rate)
GLP	:	Yes

　Test results:

This chemical did not induce structural aberrations or polyploidy under the conditions of this study.

Genetic effects:

	Clastogenicity			polyploidy
	+	?	-	+	?	-
Without metabolic activation:	[ ]	[ ]	[*]	[ ]	[ ]	[*]
With metabolic activation	[ ]	[ ]	[*]	[ ]	[ ]	[*]

1)	The tests were performed by the Safety Research Institute for Chemical Compounds Co., Ltd., 363-24 Shin-ei, Kiyota-ku, Sapporo, Hokkaido, 004-0839, Japan. Tel +81-11-885-5031, Fax +81-11-885-5313