Section 1 - CHEMICAL PRODUCT AND COMPANY IDENTIFICATION

PRODUCT NAME

HYDROQUINONE

NFPA

PRODUCT USE

Reducing agent. Used as a photographic reducer and developer; as reagent in the
determination of small quantities of phosphate; as antioxidant. Intermediate

SYNONYMS

C6-H6-O2, "C6H4-1, 4-(OH)2", "C6H4-1, 4-(OH)2", "benzene, p-dihydroxy-", "benzene, p-
dihydroxy-", "1, 4 - dihydroxybenzene", p-benzenediol, p-benzenediol, "pyrogentistic
acid", "1, 4-benzenediol", "1, 4-benzenediol", benzohydroquinone, benzoquinol, p-
hydroquinone, p-hydroquinone, p-hydroxyphenol, p-hydroxyphenol, beta-quinol

Section 2 - HAZARDS IDENTIFICATION

CANADIAN WHMIS SYMBOLS

EMERGENCY OVERVIEW

RISK

Harmful if swallowed.
Irritating to skin.
Risk of serious damage to eyes.
May cause SENSITIZATION by skin contact.
Limited evidence of a carcinogenic effect.
Possible risk of irreversible effects.
Very toxic to aquatic organisms.

POTENTIAL HEALTH EFFECTS

ACUTE HEALTH EFFECTS

SWALLOWED

  Accidental ingestion of the material may be harmful; animal experiments indicate that ingestion of less than 150 gram may be fatal or may produce serious damage to the health of the individual.  Some phenol derivatives can cause damage to the digestive system. If absorbed, profuse sweating, thirst, nausea, vomiting diarrhea, cyanosis, restlessness, stupor, low blood pressure, gasping, abdominal pain, anemia, convulsions, coma and lung swelling can happen followed by pneumonia. There may be respiratory failure and kidney damage. Chemical burns,  seizures and irregular heartbeat may result.  Ingestion of 1 gram hydroquinone caused ringing in the ears, nausea, dizziness, a sense of suffocation, increased respiration rate, vomiting, tachycardia, dark urine, muscular twitching, headache, dyspnea, cyanosis, and collapse. Death has followed ingestion of 5-  12 grams and appears to be initiated by central respiratory failure. The oxygen-carrying capacity of the blood is so severely impaired that anoxia occurs. However a controlled study of volunteers at doses of 300 - 400 mg/ day did not produce pathological changes in blood or urine.  

EYE

  If applied to the eyes, this material causes severe eye damage.  Some phenol derivatives may produce mild to severe eye irritation with redness, pain and blurred vision. Permanent eye injury may occur; recovery may also be complete or partial.  Acute exposures to high hydroquinone dust/ vapour concentrations produce irritation, photophobia, lachrymation and corneal ulceration.  

SKIN

  Skin contact with the material may damage the health of the individual; systemic effects may result following absorption.  There is some evidence to suggest that the material may cause significant and severe inflammation of the skin either following direct contact or after a delay of some time. Repeated exposure can cause contact dermatitis which is characterized by redness, swelling and blistering.  Phenol and its derivatives can cause severe skin irritation if contact is maintained, and can be absorbed to the skin affecting the cardiovascular and central nervous system. Effects include sweating, intense thirst, nausea and vomiting, diarrhea, cyanosis, restlessness, stupor, low blood pressure, hyperventilation, abdominal pain, anemia, convulsions, coma, lung swelling followed by pneumonia. Respiratory failure and kidney damage may follow.  Following exposure to hydroquinone contact dermatitis has been reported (NIOSHTIC); toxic effects by skin absorption have also been reported (Konica).  Entry into the blood-stream, through, for example, cuts, abrasions or lesions, may produce systemic injury with harmful effects. Examine the skin prior to the use of the material and ensure that any external damage is suitably protected.  

INHALED

  Inhalation may produce health damage*.  Inhalation of vapors or aerosols (mists, fumes), generated by the material during the course of normal handling, may be damaging to the health of the individual.  There is some evidence to suggest that the material can cause respiratory irritation in some persons. The body's response to such irritation can cause further lung damage.  Persons with impaired respiratory function, airway diseases and conditions such as emphysema or chronic bronchitis, may incur further disability if excessive concentrations of particulate are inhaled.  If phenols are absorbed via the lungs, systemic effects may occur affecting the cardiovascular and nervous systems. Inhalation can result in profuse perspiration, intense thirst, nausea, vomiting, diarrhea, cyanosis, restlessness, stupor, falling blood pressure, hyperventilation, abdominal pain, anemia, convulsions, coma, swelling and inflammation of the lung. This is followed by respiratory failure and kidney damage. Phenols also cause loss of sensation and general depression at high concentrations. The toxicities of phenol derivatives vary.  

CHRONIC HEALTH EFFECTS

  There has been concern that this material can cause cancer or mutations, but there is not enough data to make an assessment.  Skin contact with the material is more likely to cause a sensitization reaction in some persons compared to the general population.  Exposure to the material may result in a possible risk of irreversible effects. The material may produce mutagenic effects in man. This concern is raised, generally, on the basis ofappropriate studies using mammalian somatic cells in vivo. Such findings are often supported by positive results from in vitro mutagenicity studies.  Limited evidence suggests that repeated or long-term occupational exposure may produce cumulative health effects involving organs or biochemical systems.  Characteristic eye injuries are common amongst workers exposed during the manufacture of hydroquinone. The injuries develop over a number of years and consist of corneal changes in the curvature of the lens long after exposure has ceased after staining and pigmentation of the cornea has disappeared. Quinone, an agent used in the manufacture of hydroquinone, is thought to be the causative agent while hydroquinone dusts are thought to contribute to the injury.  Dermal exposure results from use of cosmetic skin lighteners containing hydroquinone. EEC countries have restricted content to 2% or less. USFDA proposes 1.5 to 2.0% as limits. Some countries allow more. Mice implanted with hydroquinone-containing pellets showed a significant increase in the incidence of urinary bladder carcinomas. Skin painting studies failed to confirm the role of hydroquinone as a tumour-initiator. A further study concluded that hydroquinone had a weak inhibitory action on the carcinogenicity of topical benz[a]pyrene in mouse skin.  When rats and mice received hydroquinone by gavage in drinking water in a two-year study, high dose male rats showed greater relative kidney weight and increased severity of nephropathy whilst high dose female rats showed decreased haematological indices. Relative liver weights were increased for dosed males and high dose-female mice. Thyroid gland follicular cell hyperplasia was observed in male and female mice whilst hepatic proliferative lesions were seen in male mice. Renal tubular cell adenomas were seen in male rats. Mononuclear cell leukaemia was seen in female rats. The incidence of hepatocellular neoplasms (primarily adenomas) was increased in dosed female mice.