2,4-Dinitrophenol

2,4-ジニトロフェノール


[CAS No. 51-28-5]

1-Hydroxy-2,4-dinitrobenzene

1-ヒドロキシ-2,4-ジニトロベンゼン

Molecular formula: C6H4N2O5　Molecular weight: 184.11

ABSTRACT

2,4-Dintrophenol was studied in rats in a single dose oral toxicity test at doses of 0, 45, 59, 76, 99, 129 and 167 mg/kg, and in a 28-day repeat dose toxicity test at doses of 0, 3, 10, 30 and 80 mg/kg/day.

The single dose toxicity test revealed LD50 values of 49 mg/kg for males and 51 mg/kg for females.

With regard to repeat dose toxicity, decreased locomotor activity and increased salivation were detected in both sexes at a dose of 30 mg/kg. Adoption of a prone position, panting, ptosis, a crawling position, soiling of the perigenital region and deaths were detected at a dose of 80 mg/kg, in addition to the clinical signs of decreased locomotor activity and increased salivation in both sexes. Tonic convulsions shortly before death and rigidity of body shortly after death were also apparent. Suppression of body weight gain was detected in the early phase of the administration period in females, and a tendency for suppression of the body weight gain was also evident in the latter half of the administration period in males at the same dose. On urinalysis, brown-colored urine in both sexes at doses of 30 and 80 mg/kg, and decreases in specific gravity and ketone bodies were observed in males given the dose of 80 mg/kg. Hematological examination revealed increases in hemoglobin, hematocrit and MCH in males at a dose of 80 mg/kg, and blood chemical examination revealed decrease in serum chloride in males at doses of 30 and 80 mg/kg. The relative weights of livers in both sexes and of brain, kidney and testis in males were increased at a dose of 80 mg/kg. Histopathological examination revealed mineralization in the kidney in both sexes, and atrophied red pulp due to decrease in extramedullary hematopoesis in the spleen in males at a dose of 80 mg/kg. In recovery groups, decreases in erythrocyte counts, hemoglobin and hematocrit, and increases in extramedullary hematopoesis in the spleen were detected in males at a dose of 80 mg/kg. Mineralization in the kidney was also observed at the end of the recovery period. The other changes observed in administration period or at the end of administration period had disappeared or showed a tendency for reduction. The NOELs are considered to be 10 mg/kg/day for both sexes.

Genotoxicity of 2,4-dinitrophenol was studied by a reverse mutation test in bacteria and a chromosomal aberration test in cultured Chinese hamster lung (CHL/IU) cells.

2,4-Dinitrophenol was possibly mutagenic in Salmonella typhimurium TA98 without an exogenous metabolic activation system.

2,4-Dinitrophenol induced structural chromosomal aberrations in CHL/IU cells after short-term treatment with or without an exogenous metabolic activation system.

SUMMARIZED DATA FROM THE STUDIES

1. Single Dose Oral Toxicity 1)

Purity:85.2 %
Test species/strain:Rat/Crj:CD(SD)IGS
Test method:OECD Test Guideline 401
　Route:Oral(gavage)
　Dosage:0(vehicle), 45, 59, 76, 99, 129, 167 mg/kg
　Number of animals/group:Males, 5; females, 5
　Vehicle:1 % Methylcellulose solution
GLP:Yes

　Test results:

Death occurred during about fifteen minutes to six hours after treatment in males of the 45 mg/kg or more groups and in females of the 59 mg/kg or more groups. Clinical signs such as decreased locomotor activity, adoption of a prone or crawling position and tonic convulsion in most males and females, and panting in some males and rigidity in some females were observed in the treated groups. Most of the clinical signs in the survivors hod disappeared by one day after treatment. No effects of the substance occurred with regard to body weight gain. At necropsy, dark red coloration of lung was detected in all animals found dead. No changes were detected in the survivors.

The LD50 values were estimated to be 49 mg/kg for males and 51 mg/kg for females.

2. Repeat Dose Oral Toxicity 1)

Purity:85.2 %
Test species/strain:Rat/Crj:CD(SD)IGS
Test method:Guideline for 28-Day Repeat Dose Toxicity Test in Mammalian Species (Chemical Substances Control Law of Japan)
　Route:Oral(gavage)
　Dosage:0(vehicle), 3, 10, 30, 80 mg/kg Number of animals/group
　Administration period:Males, 12; females, 12(0, 30, 80 mg/kg)
Males, 6; females, 6(3, 10 mg/kg)
　Recovery period:Males and females; 6, 6 and 6/group for the 0, 30 and 80 mg/kg, respectively
　Vehicle:1 % Methylcellulose solution
　Administration period:Males and females, 28 days
　Terminal kill:Days 29 and 43
GLP:Yes

　Test results:

Decreased locomotor activity and increased salivation were detected in both sexes at a dose of 30 mg/kg. Adoption of a prone position, panting, ptosis, crawling, soiling of the perigenital region and deaths, in addition to the clinical signs of decreased locomotor activity and increased salivation, were detected, in both sexes and two males (days 1 and 22) and six females (days 1 and 2) died at a dose of 80 mg/kg. Tonic convulsion shortly before death and body rigidity shortly after death were also apparent. Suppression of the body weight gain was detected in the early phase of the administration period in females, and a tendency for suppression of body weight gain was also detected in the latter half of the administration period in males at the same dose. On urinalysis, brown-colored urine in both sexes at doses of 30 and 80 mg/kg, and decreases in specific gravity and ketone bodies were detected in males at a dose of 80 mg/kg. Hematological examination revealed increases in hemoglobin, hematocrit and MCH in males at a dose of 80 mg/kg, and blood chemical examination revealed decrease in serum chloride in males at doses of 30 and 80 mg/kg. The relative weights of livers in both sexes and of brain, kidney and testis in males were increased at a dose of 80 mg/kg. Histopathological examination revealed mineralization in the cortico-medullary junction of the kidney in both sexes, and atrophied red pulp due to decrease in extramedullary hematopoesis in the spleen in males at a dose of 80 mg/kg. In the recovery groups, decreased erythrocyte counts, hemoglobin and hematocrit, and increased extramedullary hematopoesis in the spleen were detected in males at a dose of 80 mg/kg. Mineralization in the kidney was also observed at the end of the recovery period. The other changes observed during or at the end of the administration period had recovered or showed a tendency for recovery.

The NOEL is considered to be 10 mg/kg/day for both sexes.

3. Genetic Toxicity

3-1. Bacterial test 1)

Purity:85.2 %
Test species/strain: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
　Procedure:Pre-incubation method
　Solvent:DMSO
　Positive controls:-S9 mix; 2-(2-Furyl)-3-(5-nitro-2-furyl)acrylamide (TA100, TA98, WP2 uvrA), Sodium azide (TA1535) and 9-Aminoacridine (TA1537)
+S9 mix; 2-Aminoanthracene (all strains)
　Doses:-S9 mix; 0, 78.1, 156, 313, 625, 1250, 2500 μg/plate(TA98, TA1537)
-S9 mix; 0, 156, 313, 625, 1250, 2500, 5000 μg/plate(TA100, TA1535, WP2 uvrA)
+S9 mix; 0, 156, 313, 625, 1250, 2500, 5000 μg/plate(TA98, WP2 uvrA)
+S9 mix; 0, 78.1, 156, 313, 625, 1250, 2500 μg/plate(TA100, TA1535, TA1537)
[Confirmative test]
-S9 mix; 0, 78.1, 156, 313, 469, 625, 938, 1250, 2500 μg/plate(TA98)
　S9:Rat liver, induced with phenobarbital and 5,6-benzoflavone
　Plates/test:3
　Number of replicates:2
GLP:Yes

　Test results:

This chemical possibly induced gene mutations in S. typhimurium TA98 without S9 mix. Toxicity was observed at and above 1250 μg/plate (TA1537) and 2500 μg/plate (TA100 and TA1535), at 2500 μg/plate (TA98), and 5000 μg/plate (WP2 uvrA) without S9 mix, and observed at more than 2500 μg/plate (TA98), at 2500 μg/plate (TA100, TA1535 and TA1537), and at 5000 μg/plate (WP2 uvrA) with S9 mix.

Genotoxic effects:
Salmonella typhimurium TA98
+?-
　Without metabolic activation:[ ][*][ ]
　With metabolic activation:[ ][ ][*]

Salmonella typhimurium TA100, TA1535, 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:85.2 %
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:DMSO
　Positive controls:-S9 mix; 1-Methyl-3-nitro-1-nitrosoguanidine
+S9 mix; 3,4-Benzo[a]pyrene
　Doses:-S9 mix(6 hr short-term treatment); 0, 300, 600, 900, 1200, 1500, 1800 μg/mL
+S9 mix(6 hr short-term treatment); 0, 300, 600, 900, 1200, 1500, 1800 μg/mL
　S9:Rat liver, induced with phenobarbital and 5,6-benzoflavone
　Plates/test:2
GLP:Yes

　Test results:

With the 6 hr short-term treatment, structural chromosomal aberrations were induced at 1200 and 1500 μg/mL (11.5 and 23.0 %) without S9 mix, and at 1200, 1500 and 1800 μg/mL (17.0, 22.5 and 18.0 %) with S9 mix, respectively. Polyploidy was not induced in any treatment group.

Cytotoxicity was observed at 1800 μg/mL after 6 hr short-term treatment without S9 mix.

Lowest concentration producing cytogenetic effects in vitro:
　With and without metabolic activation (6 hr short-term treatment):1200 μg/mL(clastogenicity)

Genotoxic effects:
clastogenicitypolyploidy
+?-+?-
　Without metabolic activation:[*][ ][ ][ ][ ][*]
　With metabolic activation:[*][ ][ ][ ][ ][*]

1)The tests were performed by the Research Institute for Animal Science in Biochemistry and Toxicology, 3-7-11 Hashimotodai, Sagamihara-shi, Kanagawa 229-1132, Japan. Tel +81-42-762-2775 Fax +81-42-762-7979