[pure-silver] Hydroquinone
- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Thu, 30 Dec 2004 15:37:43 -0800
I got curious just what hazards Hydroquinone poses. The
following is from various sources as given.
Mallenkrodt-Baker MSDS:
Potential Health Effects
----------------------------------
Inhalation:
Causes irritation to the respiratory tract. Symptoms may
include coughing, shortness of breath. Systemic effects have
not been proven by this route.
Ingestion:
Highly Toxic. May cause hyperactivity, stupor, fall in blood
pressure, hyperpnea, abdominal pain, diarrhea, intense
thirst, sweating, tinnitis, nausea, dizziness, a sensation
of suffocation, an increased rate of respiration, vomiting,
pallor, muscular twitching, headache, cyanosis, delirium,
and collapse (from respiratory failure). Estimated lethal
dose lies between 5 to 12 grams (usually because of
respiratory failure from methemoglobin formation which
leaves the blood unable to carry oxygen). May cause green to
brownish-green urine.
Skin Contact:
Causes severe irritation, redness and pain. Alkaline
solutions can cause skin sensitization.
Eye Contact:
Causes severe irritation and possible corneal ulceration.
Chronic Exposure:
Repeated exposure to vapor or dust (typically 10 to 30
mg/m3) for > 5 years has caused brownish staining of the
conjunctiva which may be followed by changes to the cornea
leading to loss of visual acuity. Repeated exposure may also
cause skin effects.
Aggravation of Pre-existing Conditions:
Persons with pre-existing skin or eye disorders or impaired
respiratory function may be more susceptible to the effects
of this substance.
From another M-B MSDS:
11. Toxicological Information
Oral rat LD50: 320 mg/kg; investigated as a tumorigen,
mutagen, reproductive effector.
--------\Cancer
Lists\------------------------------------------------------
---NTP
Carcinogen---
Ingredient Known
Anticipated IARC Category
------------------------------------ ----- -----------
-------------
Hydroquinone (123-31-9) No No
3
From Fisher Scientific MSDS:
EMERGENCY OVERVIEW
Appearance: colorless, light tan, or light gray crystals.
Warning! Harmful if swallowed. May cause allergic skin
reaction. This substance has caused adverse reproductive and
fetal effects in animals. May cause cancer based on animal
studies. May cause digestive tract irritation with nausea,
vomiting, and diarrhea. Light sensitive. Air sensitive.
Causes eye and skin irritation. May cause respiratory tract
irritation. May cause dermatitis. May cause
methemoglobinemia.
Target Organs: Central nervous system, respiratory system.
Potential Health Effects
Eye: May cause eye irritation. Repeated exposure may cause
corneal abnormalities including structural changes and
brownish discoloration which can lead to decreased visual
acuity and blindness.
Skin: Causes severe skin irritation. May cause skin
sensitization, an allergic reaction, which becomes evident
upon re-exposure to this material. May cause dermatitis.
Repeated exposure may cause hyperpigmentation of fair skin
and depigmentation of dark skin.
Ingestion: May cause severe irritation of the digestive
tract. May be harmful if swallowed. May cause dizziness,
nausea, sense of suffocation, increased respiratory rate,
vomiting, pallor, muscle twitching, cyanosis (bluish
discoloration of skin due to deficient oxygenation of the
blood), delirium, collapse. May cause green or brownish
green urine which continues to darken upon standing.
Inhalation: May cause respiratory tract irritation. Causes
narcotic effects including headache, dizziness, weakness,
unconsciousness, and possible death. Vapors may cause
dizziness or suffocation. Inhalation of dust may cause
respiratory tract irritation. Exposure to high concentration
of vapor may caues irritation, photophobia, tearing, and
corneal ulceration.
Chronic: Prolonged or repeated skin contact may cause
sensitization dermatitis and possible destruction and/or
ulceration.
And:
Section 12 - Ecological Information
Ecotoxicity: Fish: Rainbow trout: LC50 = 0.097 mg/L; 96 Hr.;
UnspecifiedFish: Fathead Minnow: LC50 = 0.1-0.18 mg/L; 96
Hr.; UnspecifiedBacteria: Phytobacterium phosphoreum: EC50
=0.77-3.97 mg/L; 5,15,30 minutes; Microtox test No data
available.
Environmental: Substance has a high biological oxygen
demand, and a high potential to affect aquatic organisms.
Substance readily biodegrades, and is not likely to
bioconcentrate.
Physical: No information available.
Other: None.
And:
Epidemiology: Substance may be involved in cancer-forming
processes.
From Eastman Kodak MSDS:
===================== Ecological Information
=====================
Ecological:HIGH BIOCHEMICAL OXYGEN DEMAND, A POTENTIAL TO
CAUSE OXYGEN
DEPLETION IN AQUEOUS SYSTEMS, A HIGH POTENTIAL TO AFFECT
SOME
AQUATIC ORGANISMS, A MODERATE POTENTIAL TO AFFECT
SECONDARY WASTE
TREATMENT MI CROBIAL METABOLISM, A MODERATE POTENTIALTO
AFFECT
GERMINATION OF SOME PLANTS, A MODERATE POTENTIAL TO
AFFECT GROWTH
OF SOME PLANT, A HIGH POTENTIAL TO BIODEGRADE, A HIGH
POTENTIAL TO
PHOTOCHEMICALLY O R CHEMICALLY DEGRADE, A LOW POTENTIAL
TO
BIOCONCENTRATE. AFTER DILUTION WITH A LARGE AMOUNT OF
WATER,
FOLLOWED BY SECONDARY WASTE TREATMENT, THIS MATERIAL IS
NOT
EXPECTED TO CAUSE ADVERSE ENVIRONMENT AL EFFECTS.
Some MSDS indicate that Hydroquinone is _suspected_ of
being a contributing carcinogen to some animal cancers. I
have been unable to find the exact source or the relation
this has to human carcinogenicity. I suspect the hazard is
small. Remember that MSDS are meant to cover users of very
large quantities of a substance. They are also _legal_ not
_scientific_ docments meant to protect the issuer from legal
jeapordy. They must be interpreted with this in mind.
Hydroquinone sould be handled with care. The
protections recommended are similar to those for other
substances which pose hazards in airborne condition. Wear a
dust mask, a face protector or goggles, wear gloves, wear
protective clothing. Work in a well ventillated place. Work
in a way that minimises the chance of the substance becoming
airborne. In general, minimise contact with the substance.
A saftey booklet about Hydroquinone published by the state
of New Jersey may be found at:
http://www.state.nj.us/health/eoh/rtkweb/1019.pdf
A report on an extensive research program on the health
hazards of Hydroquinone may be found at:
http://www.inchem.org/documents/ehc/ehc/ehc157.htm
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
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