Section 1 - CHEMICAL PRODUCT AND COMPANY IDENTIFICATION

PRODUCT NAME

N-PROPYL ISOME

NFPA

PRODUCT USE

Insecticide synergist, especially for pyrethrum, allethrin, tetramethrin and rotenone. An
ingredient of insecticidal oil solutions, aerosols, dusts, wettable powders and slurries.
Manufacture of commercial grades appears to have ceased.

SYNONYMS

C20-H26-O6, "naphthalene-1, 2-dicarboxylic acid, ", "naphthalene-1, 2-dicarboxylic acid,
", "1, 2, 3, 4-tetrahydro-3-methyl-6, 7-methylenedioxy-, dipropyl ester", "1, 2, 3, 4-
tetrahydro-3-methyl-6, 7-methylenedioxy-, dipropyl ester", "di-n-propyl maleate/ iso-
safrole condensate", "di-n-propyl maleate/ iso-safrole condensate", "di-n-propyl 6, 7-
methylenedioxy-3-methyl-1, 2, 3, 4-tetrahydronaphthalene", "di-n-propyl 6, 7-
methylenedioxy-3-methyl-1, 2, 3, 4-tetrahydronaphthalene", "di-n-propyl-3-methyl-6, 7-
methylenedioxy-1, 2, 3, 4-tetrahydronaphthalene-", "di-n-propyl-3-methyl-6, 7-
methylenedioxy-1, 2, 3, 4-tetrahydronaphthalene-", "1, 2-dicarboxylate", "1, 2-
dicarboxylate", "dipropyl-5, 6, 7, 8-tetrahydro-7-methylnaphthol(2, 3-d)-1, 3-dioxole-",
"dipropyl-5, 6, 7, 8-tetrahydro-7-methylnaphthol(2, 3-d)-1, 3-dioxole-", "5, 6-
dicarboxylate", "5, 6-dicarboxylate", "ENT 15266", "propyl isome", n-isopropylisome, n-
isopropylisome, "propyl isomer", "n-propyl isomer", "n-propyl isomer",
"methylenedioxybenzene synergist"

Section 2 - HAZARDS IDENTIFICATION

CANADIAN WHMIS SYMBOLS

EMERGENCY OVERVIEW

RISK

Harmful if swallowed.
Toxic in contact with skin.
Vapors may cause dizziness or suffocation.
Very toxic to aquatic organisms, may cause long- term adverse effects in the
aquatic environment.

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.  Methylenedioxybenzene synergists cause loss of appetite, vomiting, diarrhea, inflamed bowel with bleeding, bleeding from the lung, wasting and possible central depression.  Studies suggest that by interfering with the metabolism of hormones, methylenedioxyphenol synergists such as the piperonyls (as piperonyl butoxide - PBO) may damage humeral organs such as the thyroid, adrenal, and pituitary glands. PBO has a low to moderate toxicity based on short-term laboratory animal studies. The acute oral LD50, or dose that kills half the test population, was determined to be 6.15 g/kg for rats It is predicted that the oral lethal dose for a human is 5.15 g/kg, or between 1 pint and 1 quart for a 150 lb person. Symptoms caused by ingestion of PBO in large doses include nausea, cramps, vomiting, and diarrhea. Overdoses of PBO have been shown to cause hyperexcitibility, unsteadiness, coma, seizures, and brain damage in animals. Laboratory animals exposed to single, large oral doses exhibit anorexia, vomiting, diarrhoea, unsteadiness, rough coat, watery eyes, irritability, prostration, haemorrhagic enteritis, inanition, pulmonary haemorrhage, mild central system depression, bloody discharge from eyes and nose, liver damage, coma and death. Onset may be as early as 20 minutes after dosing and death may be delayed for a week. Most rat deaths in studies are attributed to hemorrhages in the digestive tract, particularly the large intestine. Acute exposure in animals has also triggered hepatic (liver) changes and injury, anemia and loss of appetite, as well as changes in the kidneys, nasal bleeding, loss of muscle coordination, and abdominal swelling.   Chemical Watch Fact Sheet.  Central nervous system (CNS) depression may include general discomfort, symptoms of giddiness, headache, dizziness, nausea, anaesthetic effects, slowed reaction time, slurred speech and may progress to unconsciousness. Serious poisonings may result in respiratory depression and may be fatal.  

EYE

  Although the liquid is not thought to be an irritant, direct contact with the eye may produce transient discomfort characterized by tearing or conjunctival redness (as with windburn).  Acute and repeated eye contact with piperonyls (as piperonyl butoxide - PBO) has been shown to be slightly irritating, but is not linked to long-term damage.  

SKIN

  Skin contact with the material may produce toxic effects; systemic effectsmay result following absorption.  The liquid may be miscible with fats or oils and may degrease the skin, producing a skin reaction described as non-allergic contact dermatitis. The material is unlikely to produce an irritant dermatitis as described in EC Directives .  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.  Acute and repeated dermal (skin) contact with piperonyls (as piperonyl butoxide - PBO) has been shown to be slightly irritating, but is not linked to long-term damage.  In one study a lethal dose in rabbits by dermal absorption was 200 mg/kg but this result is thought to be anachronistic. A dermal applicationof PBO, at the rate of 1880 mg/kg as a 20% solution in dimethyl phthalate, produced hyperexcitability and convulsions in rabbits.  

INHALED

  The material is not thought to produce respiratory irritation (as classified using animal models). Nevertheless inhalation of vapors, fumes or aerosols, especially for prolonged periods, may produce respiratory discomfort and occasionally, distress.  Inhalation of vapours may cause drowsiness and dizziness. This may be accompanied by narcosis, reduced alertness, loss of reflexes, lack of coordination and vertigo.  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.  Methylenedioxybenzene synergists cause loss of appetite, vomiting, diarrhea, inflamed bowel with bleeding, bleeding from the lung, wasting and possible central depression.  The LD50 for inhalation of the methylenedioxyphenol synergist, piperonyl butoxide ( PBO). by rats is greater than 5.9 g/k. Inhalation of large amounts of PBO may cause tearing, salivation, labored breathing, accumulation of fluids in the lungs, and may be linked to respiratory problems, including asthma.  Exposure to high concentrations of PBO vapour may cause asthma, inflammation of the nose and mucous membrane irritation.  

CHRONIC HEALTH EFFECTS

  There has been some concern that this material can cause cancer or mutations but there is not enough data to make an assessment.  Limited evidence suggests that repeated or long-term occupational exposure may produce cumulative health effects involving organs or biochemical systems.  Based on experience with animal studies, there is a possibility that exposure to the material may result in toxic effects to the development of the fetus, at levels which do not cause significant toxic effects to the mother.  The primary effect of long-term exposure to methylenedioxyphenol insect synergists such as the piperonyls (such as piperonyl butoxide - PBO) in animals is an increase in liver and thyroid weight, liver and kidney damage, and a decrease in body weight. These symptoms were observed in a diet of 52.8 mg/kg or more a day in a chronic study with dogs.PBO is a possible human carcinogen. Currently there is no data from accidental exposure available regarding its carcinogenicity in humans; the only information is from animal studies. Several studies have shown that PBO treatment in rats causes an increase in liver cancer at high doses. The incidence of hepatocellular carcinoma, in male and female rats given 2.4% piperonyl butoxide was 80.0% and 57.7% respectively. Preneoplastic hepatic lesions such as nodular hyperplasia, cholangiofibrosis, and modular hyperplasia were also seen.Some studies have shown that PBO treatment in rats corresponds with a very slight increase in thyroid cancer.Rats fed diets containing from 0.6 to 2.4% piperonyl butoxide for approximately two years showed dose-related decreases in body weight. Roughened hair, lethargy, epistaxis, abdominal swelling, and decreased food consumption were observed at 2.4%. All dose rates induced skin tumours after about 1 year. Cumulative mortality varied from around 15 to 50%. Caecal haemorrhage was the cause of death. Dead rats with hepatic tumours were seen from week 74, but caecal haemorrhage or possible leukaemia was the cause of death. At necroscopy in rats surviving to the end of the study,  hepatocellular adenomas and carcinomas occurred in both sexes in a dose-related manner. A dose-related increase in thrombocythemia was seen in male rats. The authors * of this study concluded that the primary feature of chronic piperonyl-butoxide toxicity is hepatocarcinogenicity. It is generally accepted that PBO does not demonstrate any significant potential for mutagenicity (genetic damage) but debate still existsPBO weakens the immune system by inhibiting lymphocyte response. Lymphocytes are a class of white blood cells that consume potentially dangerous pathogens and release antibodies. Inhibiting lymphocyte response weakens the body's ability to defend against foreign invaders. Preventing the breakdown of toxic chemicals, may exacerbate potentially toxic effects.PBO has been shown to adversely affect a variety of reproductive functions. Two-generational laboratory studies on rats show that litter weight and size are less for mothers exposed to high concentrations of PBO, and there is an increase in birth defects and fetal death. In one study the difference in the average weight of PBO-exposed offspring immediately after birth is negligible, but 7-14 days post-natal is significantly greater for those mothers that are exposed to PBO than for those that are not. The U.S. EPA maintains that results for teratogenicity (the ability to produce birth defects) in animals have been mixed, and while some studies suggest some teratogenicity, most do not. PBO may also interfere with sexual development because the enzymes it inhibits are responsible not only for the breakdown of toxic chemicals but also for the metabolism of other compounds such as steroids, which include the sex hormones. Rats exposed to PBO over the course of two years experience an atrophy of the testes a decrease in weight of the seminal vesicles (sperm producing structures), and an increase in ovarian weights. There is no evidence that PBO affects fertility.Data has shown that PBO alone interferes with enzymes that maintain homeostasis of sodium and calcium in the brain and nervous system, possibly affecting neural response. Additionally, it increases the neurotoxicity of other compounds. Despite this data, EPA believes that these neurotoxic effects are slight and maintains that PBO poses no neurological risk.Behavioral changes have been noted with PBO as well. In a laboratory experiment, exposed rats experience more trouble navigating a maze than unexposed rats. The exposed rats travel longer distances and turned more frequently in the maze. PBO also induces changes in olfactory behavior of the offspring of exposed mothers. Offspring of exposed mothers are less likely to enter a compartment that smells like home than unexposed mothers. Exploratory behavior in mice increases as the dose of PBO they were treated with increased. This data shows that PBO has the ability to affect behaviors in mammals.Research on rats has found that PBO can cause intestinal ulcers and bleeding. Liver damage is common in studies,and kidney damage has been found as well. Long-term ingestion of PBO causes anemia, a decrease in the amount of hemoglobin (oxygen-transporting molecules) in blood, and increases the blood cholesterol level in rats. PBO can also damage the larynx, and there have been reports that it can cause labored breathing, an accumulation of fluid in the lungs, nasal bleeding, abdominal swelling, and loss of the ability to coordinate muscle movement. There has been a fair amount of investigation into the effects of dermal contact with PBO since it is used as a topical agent for lice, but there has been no evidence of it causing any local or systemic toxicity, and the amount of PBO absorbed from skin contact is characterized by some researchers as low.ChemicalWatch Fact SheetTakahashi, O.,S. et al: Fundamental and Applied Toxicology: Vol 22., pp 293-303, Feb 1994.