ContaminantDB: Iodine

Identification Taxonomy Biological Properties Physical Properties Toxicity Profile Spectra Concentrations Links References Targets (10)XML

Record Information

Version

1.0

Creation Date

2009-08-24 18:33:57 UTC

Update Date

2026-04-05 10:43:28 UTC

Accession Number

CHEM002572

Identification

Common Name

Iodine

Class

Small Molecule

Description

Iodine is an essential trace element. Chemically, iodine is the least reactive of the halogens, and the most electropositive halogen after astatine. However, iodine does not occur in the free state in nature. As with all other halogens , when freed from its compounds iodine forms diatomic molecules (I2). Iodine and its compounds are primarily used in medicine, photography, and dyes. Iodine is required for the production of thyroid hormones, which are essential for normal brain development, and the fetus, newborn, and young child are particularly vulnerable to iodine deficiency. Physiologically, iodine exists as an ion in the body. The iodine requirement increases during pregnancy and recommended intakes are in the range of 220-250 microg/day. Monitoring iodine status during pregnancy is a challenge. New recommendations from World Health Organization suggest that a median urinary iodine concentration >250 microg/L and <500 microg/L indicates adequate iodine intake in pregnancy. Based on this range, it appears that many pregnant women in have inadequate intakes. Thyroid-stimulating hormone concentration in the newborn is a sensitive indicator of mild iodine deficiency in late pregnancy. The potential adverse effects of mild iodine deficiency during pregnancy are uncertain. Controlled trials of iodine supplementation in mildly iodine-deficient pregnant women suggest beneficial effects on maternal and newborn serum thyroglobulin and thyroid volume, but no effects on maternal and newborn total or free thyroid hormone concentrations. There are no long-term data on the effect of iodine supplementation on birth outcomes or infant development. New data from well-controlled studies indicate that iodine repletion in moderately iodine-deficient school-age children has clear benefits: it improves cognitive and motor function; it also increases concentrations of insulin-like growth factor 1 and insulin-like growth factor-binding protein 3, and improves somatic growth. (1).

Contaminant Sources

DEA Chemicals
FooDB Chemicals
HMDB Contaminants - Urine
HPV EPA Chemicals
STOFF IDENT Compounds
T3DB toxins
ToxCast & Tox21 Chemicals

Contaminant Type

Cosmetic Toxin
Disinfectant
Food Toxin
Halogen
Household Toxin
Industrial/Workplace Toxin
Inorganic Compound
Metabolite
Natural Compound
Non-Metal

Chemical Structure

MOL SDF PDB SMILES InChI

Synonyms

Value	Source
I2	ChEBI
Jod	ChEBI
Molecular iodine	ChEBI
Diiodine	Kegg
Cadex	Kegg
Iode	HMDB
Iodine-molecule	HMDB
Iodio	HMDB
Iodum	HMDB
Jood	HMDB
Tincture iodine	HMDB
Iodine 127	MeSH, HMDB
Iodine-127	MeSH, HMDB
Iodine	ChEBI

Chemical Formula

I₂

Average Molecular Mass

253.809 g/mol

Monoisotopic Mass

253.809 g/mol

CAS Registry Number

7553-56-2

IUPAC Name

diiodine

Traditional Name

iodine

SMILES

InChI Identifier

InChI=1S/I2/c1-2

InChI Key

PNDPGZBMCMUPRI-UHFFFAOYSA-N

Chemical Taxonomy

Description

belongs to the class of inorganic compounds known as homogeneous halogens. These are inorganic non-metallic compounds in which the largest atom is a nobel gas.

Kingdom

Inorganic compounds

Super Class

Homogeneous non-metal compounds

Class

Homogeneous halogens

Sub Class

Not Available

Direct Parent

Homogeneous halogens

Alternative Parents

Not Available

Substituents

Homogeneous halogen

Molecular Framework

Not Available

External Descriptors

diatomic iodine (CHEBI:17606 )
an inorganic compound (IODINE-MOLECULE )

Biological Properties

Status

Detected and Not Quantified

Origin

Exogenous

Cellular Locations

Cytoplasm
Extracellular
Membrane

Biofluid Locations

Not Available

Tissue Locations

Not Available

Pathways

Not Available

Applications

Not Available

Biological Roles

nutrient

Chemical Roles

Not Available

Physical Properties

State

Solid

Appearance

Grey solid.

Experimental Properties

Property	Value
Melting Point	113.6°C
Boiling Point	184.4°C (363.9°F)
Solubility	0.33 mg/mL at 25°C

Predicted Properties

Property	Value	Source
logP	1.36	ChemAxon
Physiological Charge	0	ChemAxon
Hydrogen Acceptor Count	0	ChemAxon
Hydrogen Donor Count	0	ChemAxon
Polar Surface Area	0 Å²	ChemAxon
Rotatable Bond Count	0	ChemAxon
Refractivity	26.68 m³·mol⁻¹	ChemAxon
Polarizability	10.18 Å³	ChemAxon
Number of Rings	0	ChemAxon
Bioavailability	1	ChemAxon
Rule of Five	Yes	ChemAxon
Ghose Filter	No	ChemAxon
Veber's Rule	Yes	ChemAxon
MDDR-like Rule	No	ChemAxon

Spectra

Spectrum Type	Description	Splash Key	View
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	splash10-0udi-0090000000-0b4eb980a6d80c2892dd	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	Not Available	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Positive	splash10-0udi-0090000000-776e7d808857b52aa594	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Positive	splash10-0udi-0090000000-776e7d808857b52aa594	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Positive	splash10-0udi-0090000000-776e7d808857b52aa594	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Negative	splash10-0udi-0090000000-9f41876d0a547fca8258	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Negative	splash10-0udi-0090000000-9f41876d0a547fca8258	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Negative	splash10-0udi-0090000000-9f41876d0a547fca8258	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Positive	splash10-0udi-0090000000-d80218a1199b8de0e843	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Positive	splash10-0udi-0090000000-d80218a1199b8de0e843	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Positive	splash10-0udi-0090000000-d80218a1199b8de0e843	Spectrum

Toxicity Profile

Route of Exposure

Oral (5) ; inhalation (5) ; dermal (5)

Mechanism of Toxicity

Iodide inhibits adenylate cyclase in thyroid gland follicle cells and decreases the TSH-induced rise in intracellular cAMP. This results in decreased iodination of thyroglobulin and inhibited production and release of T4 and T3, causing hypothyroidism. (5)

Metabolism

Iodine can enter the body following ingestion, inhalation, or dermal exposure. In the body, iodine and iodide accumulates in the thyroid gland, where it is used for producing the thyroid hormones T4 and T3. Iodide in the thyroid gland is incorporated into a protein, thyroglobulin, as covalent complexes with tyrosine residues. The iodination of thyroglobulin is catalyzed by the enzyme thyroid peroxidase. The iodination reactions occur at the follicular cell-lumen interface and consist of the oxidation of iodide to form a reactive intermediate, the formation of monoiodotyrosine and diiodotyrosine residues in thyroglobulin, and the coupling of theiodinated tyrosine residues to form T4 (coupling of two diiodotyrosine residues) or T3 (coupling of a monoiodotyrosine and diiodotyrosine residue) in thyroglobulin. The major pathways of metabolism of iodine that occur outside of the thyroid gland involve the catabolism of T4 and T3, and include deiodination reactions, ether bond cleavage of thyronine, oxidative deamination and decarboxylation of the side chain of thyronine, and conjugation of the phenolic hydroxyl group on thyronine with glucuronic acid and sulfate. Absorbed iodine is excreted primarily in the urine and feces, but is also excreted in breast milk, exhaled air, sweat, and tears. (5)

Toxicity Values

LD50: 14 g/kg (Oral, Rat) (10)

Lethal Dose

Not Available

Carcinogenicity (IARC Classification)

No indication of carcinogenicity to humans (not listed by IARC).

Uses/Sources

Iodine is used as a disinfectant for cleaning surfaces and storage containers and is used in skin soaps and bandages, and for purifying water. Iodine is also added to some table salt to ensure that all people in the United States have enough iodine in their diet. (5)

Minimum Risk Level

Not Available

Health Effects

Exposure to high levels of nonradioactive and radioactive iodine can damage the thyroid. Damage to the thyroid gland can result in effects in other parts of your body, such as your skin, lung, and reproductive organs. Concentrated iodine is very corrosive and can damage the mucous membrane if swallowed. (5, 7)

Symptoms

Ingestion of iodine may cause corrosive effects such as oedema of the glottis, with asphyxia, aspiration pneumonia, pulmonary oedema and shock, as well as vomiting and bloody diarrhea. The CNS, cardiovascular and renal toxicity following acute iodine ingestion appear to be due to the corrosive gastroenteritis and resultant shock. Vomiting, hypotension and circulatory collapse may be noted following severe intoxication. (7)

Treatment

Sodium thiosulphate, 100 mL orally of a 1% solution, has been recommended as an antidote because it immediately reduces iodine to iodide. (7)

Concentrations

Not Available

External Links

DrugBank ID

DB05382

HMDB ID

HMDB0000675

FooDB ID

FDB003635

Phenol Explorer ID