Reported in EPA TSCA Inventory.

1. Introduction of Tetrahydrozoline hydrochloride
Tetrahydrozoline hydrochloride is the active ingredient in some brands of over-the-counter eye drops and nasal drops and sprays. It belongs to the product categories of Adrenergics; Agonists; Neurotransmitters; Intermediates & Fine Chemicals; Pharmaceuticals. What's more, both its IUPAC name and systematic name are the same which is called 2-(1,2,3,4-Tetrahydronaphthalen-1-yl)-4,5-dihydro-1H-imidazole hydrochloride. Tetrahydrozoline hydrochloride is used as an alpha agonist and can be used in over-the-counter eye drops, this compound relieves the redness left by ocular irritants.

2. Properties of Tetrahydrozoline hydrochloride
(1)ACD/LogP: 3.313; (2)# of Rule of 5 Violations: 0; (3)ACD/LogD (pH 5.5): 1.31; (4)ACD/LogD (pH 7.4): 1.35; (5)ACD/BCF (pH 5.5): 1.94; (6)ACD/BCF (pH 7.4): 2.12; (7)ACD/KOC (pH 5.5): 15.14; (8)ACD/KOC (pH 7.4): 16.53; (9)#H bond acceptors: 2; (10)#H bond donors: 1; (11)#Freely Rotating Bonds: 1; (12)Polar Surface Area: 15.6 Å²; (13)Flash Point: 191.8 °C; (14)Enthalpy of Vaporization: 61.83 kJ/mol; (15)Boiling Point: 393.5 °C at 760 mmHg; (16)Vapour Pressure: 4.8E-06 mmHg at 25 °C

3. Structure Descriptors of Tetrahydrozoline hydrochloride
(1) SMILES: Cl.N\1=C(\NCC/1)C3c2ccccc2CCC3
(2) InChI: InChI=1S/C13H16N2.ClH/c1-2-6-11-10(4-1)5-3-7-12(11)13-14-8-9-15-13;/h1-2,4,6,12H,3,5,7-9H2,(H,14,15);1H
(3) InChIKey: BJORNXNYWNIWEY-UHFFFAOYSA-N

4. Toxicity of Tetrahydrozoline hydrochloride

Organism	Test Type	Route	Reported Dose (Normalized Dose)	Effect	Source
bird - domestic	LD50	intramuscular	150mg/kg (150mg/kg)		Compilation of LD50 Values of New Drugs.
child	TDLo	oral	175mg/kg (175mg/kg)	BRAIN AND COVERINGS: RECORDINGS FROM SPECIFIC AREAS OF CNS LUNGS, THORAX, OR RESPIRATION: RESPIRATORY DEPRESSION ENDOCRINE: HYPOGLYCEMIA	Clinical Pediatrics Vol. 35, Pg. 539, 1996.
infant	TDLo	unreported	80mg/kg (80mg/kg)	BEHAVIORAL: SLEEP LUNGS, THORAX, OR RESPIRATION: DYSPNEA	Spokane County Medical Society Bulletin. Vol. 29, Pg. 17, 1955.
mouse	LD50	intraperitoneal	110mg/kg (110mg/kg)		Compilation of LD50 Values of New Drugs.
mouse	LD50	intravenous	39mg/kg (39mg/kg)		"Handbook of Analytical Toxicology," Sunshine, I., ed., Cleveland, OH, Chemical Rubber Co., 1969Vol. -, Pg. 113, 1969.
mouse	LD50	oral	345mg/kg (345mg/kg)	BEHAVIORAL: CONVULSIONS OR EFFECT ON SEIZURE THRESHOLD BEHAVIORAL: SOMNOLENCE (GENERAL DEPRESSED ACTIVITY) LUNGS, THORAX, OR RESPIRATION: DYSPNEA	Drugs in Japan Vol. 6, Pg. 495, 1982.
mouse	LD50	subcutaneous	245mg/kg (245mg/kg)	LUNGS, THORAX, OR RESPIRATION: DYSPNEA BEHAVIORAL: CONVULSIONS OR EFFECT ON SEIZURE THRESHOLD BEHAVIORAL: SOMNOLENCE (GENERAL DEPRESSED ACTIVITY)	Drugs in Japan Vol. 6, Pg. 495, 1982.
rat	LD50	intraperitoneal	122mg/kg (122mg/kg)	BEHAVIORAL: SOMNOLENCE (GENERAL DEPRESSED ACTIVITY) BEHAVIORAL: CONVULSIONS OR EFFECT ON SEIZURE THRESHOLD LUNGS, THORAX, OR RESPIRATION: DYSPNEA	Drugs in Japan Vol. 6, Pg. 495, 1982.
rat	LD50	intravenous	35mg/kg (35mg/kg)	BEHAVIORAL: CONVULSIONS OR EFFECT ON SEIZURE THRESHOLD BEHAVIORAL: SOMNOLENCE (GENERAL DEPRESSED ACTIVITY) LUNGS, THORAX, OR RESPIRATION: DYSPNEA	Drugs in Japan Vol. 6, Pg. 495, 1982.
rat	LD50	oral	785mg/kg (785mg/kg)	BEHAVIORAL: CONVULSIONS OR EFFECT ON SEIZURE THRESHOLD BEHAVIORAL: SOMNOLENCE (GENERAL DEPRESSED ACTIVITY) LUNGS, THORAX, OR RESPIRATION: DYSPNEA	Drugs in Japan Vol. 6, Pg. 495, 1982.
rat	LD50	subcutaneous	500mg/kg (500mg/kg)	LUNGS, THORAX, OR RESPIRATION: DYSPNEA BEHAVIORAL: CONVULSIONS OR EFFECT ON SEIZURE THRESHOLD BEHAVIORAL: SOMNOLENCE (GENERAL DEPRESSED ACTIVITY)	Drugs in Japan Vol. 6, Pg. 495, 1982.

5. Safety Information of Tetrahydrozoline hydrochloride
Hazard Symbols:Xi;Xn
Risk Codes:
R22:Harmful if swallowed. 
R36/37/38:Irritating to eyes, respiratory system and skin.
Safety Description:
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 
S36:Wear suitable protective clothing.

6. Use of Tetrahydrozoline hydrochloride
Tetrahydrozoline hydrochloride is a vasoconstrictor, meaning it shrinks blood vessels. This makes it useful as a topical treatment for relieving nasal congestion and eye redness, itching and minor irritation. As a nasal congestion therapy, some products with tetrahydrozoline hydrochloride may also contain zinc sulfate, which has an astringent effect -- it constricts body tissue.

7. Other details of Tetrahydrozoline hydrochloride
When you are dealing with Tetrahydrozoline hydrochloride, you should be very careful. This chemical may cause damage to health and may cause inflammation to the skin or other mucous membranes. It is harmful if swallowed and it is irritating to eyes, respiratory system and skin. Therefore, you should wear suitable protective clothing. In case of contacting with eyes, you should rinse immediately with plenty of water and seek medical advice.