In microbiology laboratory, we are working with different kind of chemicals based on the experimental requirements and laboratory cleaning purpose. All the chemicals are not toxic but the direct contact with some chemicals will cause a severe effect on biological life which includes both the experimental specimen and the experimenter. The chances for direct contact of hazardous chemicals with the skin, oral intake by mouth pipetting and inhalation of the hazardous fume should be reduced or avoided. The fume can also cause redness of the eye, eye burning and irritation. The general hazardous chemicals are known by its nature and effect on biological life.
The chemicals which need to be handled with care are the staining dyes, acids, bases and toxic solvents. In any mean, the working person should not get any contact with these hazardous compounds with their skin, face or hair. It should be handled with safety aspects.
Why Does Hydrogen Peroxide Fizz On Cuts?
Someone got a boo boo.
Credit: Elder Vieira Salles/Shutterstock
When you dab hydrogen peroxide on a cut, that white, fizzling foam is actually a sign that that the solution is killing bacteria as well as healthy cells.
Hydrogen peroxide (H2O2), a compound made up of two hydrogen atoms and two oxygen atoms, begins to breaks apart as soon as it contacts blood, creating that stinging sizzle. This is because blood and most living cells contain the enzyme catalase, which attacks hydrogen peroxide and converts it into water (H2O) and oxygen (O2).
Hydrogen peroxide has been used as an antiseptic since the 1920s because it kills bacteria cells by destroying their cell walls. This process is called oxidation because the compound's oxygen atoms are incredibly reactive, and they attract, or steal, electrons. With fewer electrons, bacteria cells' walls become damaged or even completely break apart.
Unfortunately, hydrogen peroxide's oxidation also destroys healthy skin cells. This is why many physicians and dermatologists currently advise against using hydrogen peroxide to clean wounds , as it has been found to slow the healing process and possibly worsen scarring by killing the healthy cells surrounding a cut.
Despite its negative effect on healthy cells, our bodies' cells naturally produce hydrogen peroxide when we metabolize food and turn it into energy. So how can a cell produce something that can destroy its own walls? That's where catalase steps in: when a cell creates hydrogen peroxide, it stores it inside the cell's specialized organelles, called peroxisomes, which contain hydrogen peroxide-busting catalase. Inside of a peroxisome, hydrogen peroxide decomposes and is turned into harmless water and oxygen gas .
Catalase is present in the cells of nearly all living organisms, so next time you want to amuse the kids with a fun science trick, pour some hydrogen peroxide on half of a raw potato and watch it fizzle.
Stains and Dyes:
A chemical coloring agent that has the ability to react with biological materials like proteins, amino acids and polysaccharides to stain them as colored complex. the stains that spill on hands will immediately react with the surface proteins and polysaccharides present on the skin. It cannot be easily washed away from hands with soap or detergent solution but repeating the wash followed by an alcohol wash can remove the stains from skin. It is better to wear hand gloves while handling stains will prevent it from getting spilled on hands.
Biological Stains
Acids:
The concentrated acids or the acid concentration above 40% can cause a corrosive effect on skin tissues. The acid reacts with the biological molecules present on the skin and hydrolyzes them by acid-base catalysis. The hydrolysis of biological molecules produces a large amount of heat that will burn or shrinks the tissue.
The acid burn on the skin cannot be reversible. Immediately flooding the acid burn with running water for twenty minutes can control the acid effect from spreading to larger surface of the skin. Do not pour water over acids in the burning area, it will dilute acid and produce the more burning effect. It should be done only with running water so the acid will be diluted and flood away from the skin.
Common hazardous acids
Bases:
The concentrated bases have the ability to lyse, dissolve and denature any kind of biological materials includes nucleic acid materials. The hydrolysis of biological materials by bases produce an enormous amount of heat that will irritate and severely burns the skin.
The damage caused by chemical base on the skin is permanent. Immediate washing the affected area with running water can reduce the effect of burnings. The burns caused by bases are greater than acids since the base can produce more amount of heat when denaturing biological materials.
Common hazardous bases
Solvents:
Solvent has the ability to dissolve any substance. In microbiology laboratory, many kinds of solvents are used in large quantities based on their requirements. the toxicity of solvents is determined by its unfavorable odor, the effect on biological material, flammable nature, stability at room temperature etc. Care should be taken while taking and transferring solvents for experimental purpose. Vaporising and odor producing solvents can be transferred under fume hoods.
Common hazardous Solvents
Culture Media:
Culture media is the mixture of different nutritive substances that support the growth and metabolism of microorganisms. It is available solid, semi-solid and liquid forms. It is readily soluble in water media is readily
Oxidizers: Inorganic Nitrates, Nitrites, Permanganates, Chlorates, Perchlorates, Iodates, Periodates, Persulfates, Chromates, Hypochlorites, Peroxides, Perborates (ex: Potassium Perchlorate, Calcium hypochlorite, Sodium nitrate, Sodium iodate, Ammonium persulfate, Sodium peroxide)
Oxidizing acids:
Nitric acid, Perchloric acid, Hydrogen peroxide, Periodic acid, Chromic acid
Flammable liquids:
Methanol, Ethanol, Acetone, Xylene, Toluene, Ethyl acetate, Tetrahydrofuran, Ethyl ether, Benzene, Dimethylformamide, Acetonitrile, Hexane, Pyridine, etc.
Basic flammable liquids:
Flammable amines such as: Triethylamine, Diethylamine, TEMED, Ethylaminediamine,
Trimethylamine solution, Pyrrolidine, Morpholine, Cyclohexylamine, Sodium methylate (in methanol solution), etc.
Inorganic bases:
Metal hydroxides such as Sodium, Potassium, Calcium, Nickel hydroxide Ammonium hydroxide,
Organic bases:
Amines such as Ethanolamine, Tributylamine, etc.
Acidic Flammable Liquids:
Glacial acetic acid (100%), Acetic acid (>80%), Acetic anhydride, Formic acid (>85%), Propanoic acid (100%) (also called Propionic acid)
Mixtures of acids and flammable liquids
Organic Acids:
Butyric acid, Pentanoic acid, etc.
Inorganic acids:
Hydrochloric acid, Sulfuric acid, Phosphoric acid, Hydrofluoric Acid, etc
Poisons (Toxic chemicals)
Many are in aqueous solution, but they are also available as mixtures or pure compounds, such as Acrylamide, Formaldehyde, Glutaraldehyde, Chloroform, Phenol, Methylene chloride
Toxic metal salts such as Silver chloride, Cadmium sulfate, Mercury acetate, Barium carbonate, Lead acetate, etc.
Biological stains
Cyanides
Sodium cyanide, Potassium cyanide, Calcium cyanide
Sulfides
Lead sulfide, Iron sulfide [some metal sulfides, when they have low water content, such as Sodium and Potassium sulfides, are pyrophoric]
Pyrophorics (air-reactive):
Metal alkyls and aryls, such as Methyllithium, Trimethylaluminum, Diethylzinc, phenyllithium
Nonmetal alkyls, such as Triethylborane, Trimethylphosphine
Phosphorus (white)
Note: Careful when packaged under water, don’t store in an area where water reactives are present
Metal alkyl hydrides and halides such as Diisobutylaluminum hydride, Dimethylaluminum chloride,
Titanium trichloride, tert-Butyl hypochlorite, Lithium diethylamide, Lithium diisopropylamide, Sodium methoxide (Sodium methylate), Sodium sulfide [anhydrous or <30% water], Raney Nickel Catalyst
Water-reactives
Alkali metals such as Sodium,Lithium, Potassium
Metal powders such as Alumium, Cobalt, Iron, Magnesium, Manganese, Palladium, Platnium, Tin, Titanium, Zinc, Zirconium
Borane complexes such as Borane-dimethylamine complex, Borane-methyl sulfide complex
Carbides such as Calcium carbide
Grignard reagents such as Phenylmagnesium bromide, Ethylmagnesium chloride
Metal hydrides and Borohydrides such as Sodium hydride, Potassium borohydride, Lithium aluminum hydride
Metal phosphides such as Aluminum phosphide, Calcium phosphide, Sodium phosphide
Others: Trichlorosilane, Phosphorous pentasulfide
Water-Reactive acids
Chlorosilanes such as Dimethyldichlorosilane, Ethyltrichlorosilane
Acid halides such as Acetyl chloride,Benzenesulfonyl bromide, Propanoyl chloride
Phosphorous pentoxide (also called Phosphoric anhydride, when mixed with water, may boil from the heat generated)
Non-Hazardous or non-regulated chemicals
Buffers, Surfactants, Ion exchange resins, Alumina, Silica, Culture media, Agarose, Albumin, Pump oil,
Non-hazardous salts such as Sodium chloride, Magnesium sulfate, Potassium phosphate, Calcium acetate, etc.
Note: Always look for the presence of toxic preservative compounds in “non-hazardous products” such as. Mercury or Azide salts in buffers]
Harmful Effects of Acrylamide
Human exposure to acrylamide primarily comes from dermal contact with solid monomer and inhalation of dust and vapor in the occupational setting. The public may be exposed to acrylamide through the ingestion of drinking water that is contaminated with acrylamide or the intake of acrylamide from food.
Major health effects of acrylamide are skin irritation such as redness and peeling of the skin of palms and neuropathy regarding the central nervous system and the peripheral nervous system. Acute and subacute intoxication with a large dose by ingestion water drink contaminated with acrylamide can cause severe symptoms of the central nervous system and polyneuropathy may appear later (17). Long term exposure to acrylamide produces a motor and sensory polyneuropathy that is insidious and distal in onset (12). Although severe exposure may result in permanent sequelae, affected humans recovered within several months to one year after cessation of exposure (13, 17).
CNS (central nervous system) symptoms : drowsiness, disturbance of balance, and mental changes characterized by confusion, hallucinations, memory loss
Peripheral polyneuropathy : numbness of lower limbs, tingling of the fingers, tenderness to the touch, decreased pinprick sensation, vibratory loss, weak or absent tendon reflexes such as knee jerk, positive Romberg’s sign, ataxic gait, foot drop and muscular atrophy of the extremities
1. Acute toxicity : Acrylamide is a skin and respiratory tract irritant in humans. Reported oral LD50 values are in the range of 159 mg/kg to 300 mg/kg body weight (bw) in rats (14).
2. Subchronic/Chronic Toxicity : Acrylamide is a human neurotoxicant. Adverse effects in rats administered small amounts of acrylamide include general systemic toxicity and hematological changes. Acrylamide is also a neurotoxicant to animals.
In rats, repeated oral administration of acrylamide at doses of 20 mg/kg bw/day and above produced peripheral neuropathy, atrophy of skeletal muscle, and decreased erythrocyte parameters. At 5 mg/kg bw/day in a 90-day study in rats, peripheral lesions occurred and slight changes in peripheral nerve tissue could see only by electron microscopy at 1 mg/kg bw/day. No effects were seen at 0.2 mg/kg bw/day (16).
In monkeys, clinical signs of peripheral neuropathy occurred at doses of 10 mg/kg bw/day for up to 12 weeks(16).
3. Carcinogenicity : Although inadequate evidence is available from human studies, several laboratory animal studies have shown that acrylamide causes a variety of tumors in rats and mice. Acrylamide has been classified by the U.S. EPA as a B2, a probable human carcinogen, by IARC as a 2B, a possible human carcinogen, and by ACGIH as an A3, confirmed animal carcinogen with unknown relevance to human.
Although two cohort mortality studies of occupational exposure to acrylamide have been conducted, they were inadequate to evaluate the potential carcinogenicity of humans (14).
Two long-term studies in male and female rats were given the range of 0 to 3.0 mg/kg bw/day acrylamide in drinking water for 2 years. At the two highest doses, they observed the incidence of tumors increased in the scrotum, adrenal, thyroid, mammary, oral cavity, and uterus. Tumors of the brain and spinal cord were also seen in studies, but they did not show clear dose responses and did not attain statistical significance(14, 15).
Male and female mice given 6.25, 12.5, or 25 mg/kg bw/day, 3 times/week, for 8 weeks by gavage had a dose-responsive increase in lung adenoma (14).
4. Genotoxicity : Acrylamide causes chromosomal aberrations, dominant lethality, sister chromatid exchanges and unscheduled DNA synthesis in various in vitro and in vivo systems. When administered at a level of 500 ppm in the diet for 3 weeks in mice, acrylamide caused a high frequency of sister chromatid exchanges and breaks (14).
5. Developmental/Reproductive Toxicity : No information was found on the developmental/reproductive effects of acrylamide in humans. Acrylamide does not appear to cause structural developmental defects by oral administration to rats. Testicular atrophy and decreased fertility have been reported in male mice given acrylamide by mouth.
Impaired fertility associated with effects on sperm count and sperm mobility parameters has been demonstrated in male rats exposed to 15 mg/kg bw/day or more for 5 days. But in other rat studies effects on fertility were less clear. No effects on fertility in rats were observed in a 2-generation reproduction study in which males and females of each generation received 5 mg/kg bw/day for 10 to 11 weeks (15).
Male mice treated with 0.035 g/kg by gavage 2 times/week, for 8 weeks had testicular atrophy, reduced numbers of spermatozoa, degenerating spermatids and spermatocytes, and multinucleate giant cells (14)
6. Neurotoxicity : Acrylamide is a neurotoxin by either oral (in animals) or inhalation exposure (in humans and in animals). Toxic effects are central and peripheral neuropathy causing drowsiness, hallucinations, distal numbness, and ataxia. Recovery is possible after cessation of exposure. EPA has derived an oral reference dose (RfD) of 0.0002 mg/kg/day for acrylamide, based on adverse nervous system effects in laboratory animals.
A study of factory workers exposed to 0.07 to 2.5 times the NIOSH recommended exposure limit (REL 0.03 mg/m3, is roughly equivalent to 0.004 mg/kg bw/day for an 8-hour work day) showed a dose response relationship for abnormal sensation, decreased motor strength, abnormal gait, and skin abnormalities (14).
In microbiology laboratory, we are working with different kind of chemicals based on the experimental requirements and laboratory cleaning purpose. All the chemicals are not toxic but the direct contact with some chemicals will cause a severe effect on biological life which includes both the experimental specimen and the experimenter. The chances for direct contact of hazardous chemicals with the skin, oral intake by mouth pipetting and inhalation of the hazardous fume should be reduced or avoided. The fume can also cause redness of the eye, eye burning and irritation. The general hazardous chemicals are known by its nature and effect on biological life.
The chemicals which need to be handled with care are the staining dyes, acids, bases and toxic solvents. In any mean, the working person should not get any contact with these hazardous compounds with their skin, face or hair. It should be handled with safety aspects.
Stains and Dyes:
A chemical coloring agent that has the ability to react with biological materials like proteins, amino acids and polysaccharides to stain them as colored complex. the stains that spill on hands will immediately react with the surface proteins and polysaccharides present on the skin. It cannot be easily washed away from hands with soap or detergent solution but repeating the wash followed by an alcohol wash can remove the stains from skin. It is better to wear hand gloves while handling stains will prevent it from getting spilled on hands.
Biological Stains
Acids:
The concentrated acids or the acid concentration above 40% can cause a corrosive effect on skin tissues. The acid reacts with the biological molecules present on the skin and hydrolyzes them by acid-base catalysis. The hydrolysis of biological molecules produces a large amount of heat that will burn or shrinks the tissue.
The acid burn on the skin cannot be reversible. Immediately flooding the acid burn with running water for twenty minutes can control the acid effect from spreading to larger surface of the skin. Do not pour water over acids in the burning area, it will dilute acid and produce the more burning effect. It should be done only with running water so the acid will be diluted and flood away from the skin.
Common hazardous acids
Bases:
The concentrated bases have the ability to lyse, dissolve and denature any kind of biological materials includes nucleic acid materials. The hydrolysis of biological materials by bases produce an enormous amount of heat that will irritate and severely burns the skin.
The damage caused by chemical base on the skin is permanent. Immediate washing the affected area with running water can reduce the effect of burnings. The burns caused by bases are greater than acids since the base can produce more amount of heat when denaturing biological materials.
Common hazardous bases
Solvents:
Solvent has the ability to dissolve any substance. In microbiology laboratory, many kinds of solvents are used in large quantities based on their requirements. the toxicity of solvents is determined by its unfavorable odor, the effect on biological material, flammable nature, stability at room temperature etc. Care should be taken while taking and transferring solvents for experimental purpose. Vaporising and odor producing solvents can be transferred under fume hoods.
Common hazardous Solvents
Culture Media:
Culture media is the mixture of different nutritive substances that support the growth and metabolism of microorganisms. It is available solid, semi-solid and liquid forms. It is readily soluble in water media is readily
Oxidizers: Inorganic Nitrates, Nitrites, Permanganates, Chlorates, Perchlorates, Iodates, Periodates, Persulfates, Chromates, Hypochlorites, Peroxides, Perborates (ex: Potassium Perchlorate, Calcium hypochlorite, Sodium nitrate, Sodium iodate, Ammonium persulfate, Sodium peroxide)
Oxidizing acids:
Nitric acid, Perchloric acid, Hydrogen peroxide, Periodic acid, Chromic acid
Flammable liquids:
Methanol, Ethanol, Acetone, Xylene, Toluene, Ethyl acetate, Tetrahydrofuran, Ethyl ether, Benzene, Dimethylformamide, Acetonitrile, Hexane, Pyridine, etc.
Basic flammable liquids:
Flammable amines such as: Triethylamine, Diethylamine, TEMED, Ethylaminediamine,
Trimethylamine solution, Pyrrolidine, Morpholine, Cyclohexylamine, Sodium methylate (in methanol solution), etc.
Inorganic bases:
Metal hydroxides such as Sodium, Potassium, Calcium, Nickel hydroxide Ammonium hydroxide,
Organic bases:
Amines such as Ethanolamine, Tributylamine, etc.
Acidic Flammable Liquids:
Glacial acetic acid (100%), Acetic acid (>80%), Acetic anhydride, Formic acid (>85%), Propanoic acid (100%) (also called Propionic acid)
Mixtures of acids and flammable liquids
Organic Acids:
Butyric acid, Pentanoic acid, etc.
Inorganic acids:
Hydrochloric acid, Sulfuric acid, Phosphoric acid, Hydrofluoric Acid, etc
Poisons (Toxic chemicals)
Many are in aqueous solution, but they are also available as mixtures or pure compounds, such as Acrylamide, Formaldehyde, Glutaraldehyde, Chloroform, Phenol, Methylene chloride
Toxic metal salts such as Silver chloride, Cadmium sulfate, Mercury acetate, Barium carbonate, Lead acetate, etc.
Biological stains
Cyanides
Sodium cyanide, Potassium cyanide, Calcium cyanide
Sulfides
Lead sulfide, Iron sulfide [some metal sulfides, when they have low water content, such as Sodium and Potassium sulfides, are pyrophoric]
Pyrophorics (air-reactive):
Metal alkyls and aryls, such as Methyllithium, Trimethylaluminum, Diethylzinc, phenyllithium
Nonmetal alkyls, such as Triethylborane, Trimethylphosphine
Phosphorus (white)
Note: Careful when packaged under water, don’t store in an area where water reactives are present
Metal alkyl hydrides and halides such as Diisobutylaluminum hydride, Dimethylaluminum chloride,
Titanium trichloride, tert-Butyl hypochlorite, Lithium diethylamide, Lithium diisopropylamide, Sodium methoxide (Sodium methylate), Sodium sulfide [anhydrous or <30% water], Raney Nickel Catalyst
Water-reactives
Alkali metals such as Sodium,Lithium, Potassium
Metal powders such as Alumium, Cobalt, Iron, Magnesium, Manganese, Palladium, Platnium, Tin, Titanium, Zinc, Zirconium
Borane complexes such as Borane-dimethylamine complex, Borane-methyl sulfide complex
Carbides such as Calcium carbide
Grignard reagents such as Phenylmagnesium bromide, Ethylmagnesium chloride
Metal hydrides and Borohydrides such as Sodium hydride, Potassium borohydride, Lithium aluminum hydride
Metal phosphides such as Aluminum phosphide, Calcium phosphide, Sodium phosphide
Others: Trichlorosilane, Phosphorous pentasulfide
Water-Reactive acids
Chlorosilanes such as Dimethyldichlorosilane, Ethyltrichlorosilane
Acid halides such as Acetyl chloride,Benzenesulfonyl bromide, Propanoyl chloride
Phosphorous pentoxide (also called Phosphoric anhydride, when mixed with water, may boil from the heat generated)
Non-Hazardous or non-regulated chemicals
Buffers, Surfactants, Ion exchange resins, Alumina, Silica, Culture media, Agarose, Albumin, Pump oil,
Non-hazardous salts such as Sodium chloride, Magnesium sulfate, Potassium phosphate, Calcium acetate, etc.
Note: Always look for the presence of toxic preservative compounds in “non-hazardous products” such as. Mercury or Azide salts in buffers]
Harmful Effects of Acrylamide
Human exposure to acrylamide primarily comes from dermal contact with solid monomer and inhalation of dust and vapor in the occupational setting. The public may be exposed to acrylamide through the ingestion of drinking water that is contaminated with acrylamide or the intake of acrylamide from food.
Major health effects of acrylamide are skin irritation such as redness and peeling of the skin of palms and neuropathy regarding the central nervous system and the peripheral nervous system. Acute and subacute intoxication with a large dose by ingestion water drink contaminated with acrylamide can cause severe symptoms of the central nervous system and polyneuropathy may appear later (17). Long term exposure to acrylamide produces a motor and sensory polyneuropathy that is insidious and distal in onset (12). Although severe exposure may result in permanent sequelae, affected humans recovered within several months to one year after cessation of exposure (13, 17).
CNS (central nervous system) symptoms : drowsiness, disturbance of balance, and mental changes characterized by confusion, hallucinations, memory loss
Peripheral polyneuropathy : numbness of lower limbs, tingling of the fingers, tenderness to the touch, decreased pinprick sensation, vibratory loss, weak or absent tendon reflexes such as knee jerk, positive Romberg’s sign, ataxic gait, foot drop and muscular atrophy of the extremities
1. Acute toxicity : Acrylamide is a skin and respiratory tract irritant in humans. Reported oral LD50 values are in the range of 159 mg/kg to 300 mg/kg body weight (bw) in rats (14).
2. Subchronic/Chronic Toxicity : Acrylamide is a human neurotoxicant. Adverse effects in rats administered small amounts of acrylamide include general systemic toxicity and hematological changes. Acrylamide is also a neurotoxicant to animals.
In rats, repeated oral administration of acrylamide at doses of 20 mg/kg bw/day and above produced peripheral neuropathy, atrophy of skeletal muscle, and decreased erythrocyte parameters. At 5 mg/kg bw/day in a 90-day study in rats, peripheral lesions occurred and slight changes in peripheral nerve tissue could see only by electron microscopy at 1 mg/kg bw/day. No effects were seen at 0.2 mg/kg bw/day (16).
In monkeys, clinical signs of peripheral neuropathy occurred at doses of 10 mg/kg bw/day for up to 12 weeks(16).
3. Carcinogenicity : Although inadequate evidence is available from human studies, several laboratory animal studies have shown that acrylamide causes a variety of tumors in rats and mice. Acrylamide has been classified by the U.S. EPA as a B2, a probable human carcinogen, by IARC as a 2B, a possible human carcinogen, and by ACGIH as an A3, confirmed animal carcinogen with unknown relevance to human.
Although two cohort mortality studies of occupational exposure to acrylamide have been conducted, they were inadequate to evaluate the potential carcinogenicity of humans (14).
Two long-term studies in male and female rats were given the range of 0 to 3.0 mg/kg bw/day acrylamide in drinking water for 2 years. At the two highest doses, they observed the incidence of tumors increased in the scrotum, adrenal, thyroid, mammary, oral cavity, and uterus. Tumors of the brain and spinal cord were also seen in studies, but they did not show clear dose responses and did not attain statistical significance(14, 15).
Male and female mice given 6.25, 12.5, or 25 mg/kg bw/day, 3 times/week, for 8 weeks by gavage had a dose-responsive increase in lung adenoma (14).
4. Genotoxicity : Acrylamide causes chromosomal aberrations, dominant lethality, sister chromatid exchanges and unscheduled DNA synthesis in various in vitro and in vivo systems. When administered at a level of 500 ppm in the diet for 3 weeks in mice, acrylamide caused a high frequency of sister chromatid exchanges and breaks (14).
5. Developmental/Reproductive Toxicity : No information was found on the developmental/reproductive effects of acrylamide in humans. Acrylamide does not appear to cause structural developmental defects by oral administration to rats. Testicular atrophy and decreased fertility have been reported in male mice given acrylamide by mouth.
Impaired fertility associated with effects on sperm count and sperm mobility parameters has been demonstrated in male rats exposed to 15 mg/kg bw/day or more for 5 days. But in other rat studies effects on fertility were less clear. No effects on fertility in rats were observed in a 2-generation reproduction study in which males and females of each generation received 5 mg/kg bw/day for 10 to 11 weeks (15).
Male mice treated with 0.035 g/kg by gavage 2 times/week, for 8 weeks had testicular atrophy, reduced numbers of spermatozoa, degenerating spermatids and spermatocytes, and multinucleate giant cells (14)
6. Neurotoxicity : Acrylamide is a neurotoxin by either oral (in animals) or inhalation exposure (in humans and in animals). Toxic effects are central and peripheral neuropathy causing drowsiness, hallucinations, distal numbness, and ataxia. Recovery is possible after cessation of exposure. EPA has derived an oral reference dose (RfD) of 0.0002 mg/kg/day for acrylamide, based on adverse nervous system effects in laboratory animals.
A study of factory workers exposed to 0.07 to 2.5 times the NIOSH recommended exposure limit (REL 0.03 mg/m3, is roughly equivalent to 0.004 mg/kg bw/day for an 8-hour work day) showed a dose response relationship for abnormal sensation, decreased motor strength, abnormal gait, and skin abnormalities (14).