knows what they are....you see them in their gardens looking after their
Hostas' sprinkling slug pellets about like they were sowing seed.....bad
habit, Slug pellets contain a chemical called METALDEHYDE, and it isn't
nice. I can tell you from personal experience that they taste quite sweet,
so that is a good starter for the grand children when they are roaming about
in the garden. "Hey look here, granny has dropped some bluey-green
sweeties in the garden, do you want one?"....OOOPS. Perhaps when you
read below you might be more careful about when and how slug pellets are
used. There are green alternatives on the market, just type "green
slug control" into Google and it will find the site for you.
Chemical Name (IUPAC):
r-2, c-4, c-6, c-8-tetramethyl-1,3,5,7-tetroxocane or more usually as metacetaldehyde
108-62-3. (the homopolymer is 9002-91-9).
and Other Names: Some
trade names include Antimilace, Antimitace, Ariotox, Cekumeta, Deadline,
Halizan, Limatox, Meta, Metason, Namekil, Ortho Metaldehyde 4% Bait, Slug
Death, Slug Pellets, Slug-Tox and Slugit Pellets. Mini-Slug Pellets. Some
of the above names are USA trade names, so don't you UK types go lookin
- Acute toxicity: Metaldehyde is slightly
to moderately toxic by ingestion, with reported oral LD50 values of
227 to 690 mg/kg in rats, 207 mg/kg in cats, 100 to 1000 mg/kg in dogs,
200 mg/kg in mice, 175 to 700 mg/kg in guinea pigs, and 290 to 1250
mg/kg in rabbits. A child died after ingesting 3000 mg (approximately
75 to 100 mg/kg for a 30 to 40 kg child) of metaldehyde. Via the dermal
route, it is also moderately toxic. The dermal LD50 for this molluscicide
in rats is from 2275 mg/kg to greater than 5000 mg/kg. Metaldehyde is
moderately toxic by inhalation; the 4-hour inhalation LC50 in rats is
0.2 mg/L, and the 2-hour inhalation LC50 in mice is 0.35 mg/L. Irritation
of the skin, eye, and mucous membranes of the upper airways and gastrointestinal
tract may result from contact with metaldehyde. Within a few hours of
accidental or intentional ingestion, the following symptoms appeared
in humans: severe abdominal pain, nausea, vomiting, diarrhea, fever,
convulsions, coma, and persistent memory loss. Other symptoms of high
acute exposure include increased heart rate, panting, asthma attack,
depression, drowsiness, high blood pressure, inability to control the
release of urine and feces, incoordination, muscle tremors, sweating,
excessive salivation, tearing, cyanosis, acidosis, stupor, and unconsciousness
and eventual death in extreme cases. Kidney injury and liver cell death
('necrosis') may also occur. Mental deficiencies and memory loss from
ingestion poisoning may persist for 1 year or more. It is thought that
the formation of acetaldehyde in the gastrointestinal tract is responsible
for the narcotic effects observed with metaldehyde exposure.
- Chronic toxicity: Dosages which are
not toxic when given singly do not cause illness when repeated. Long-term,
repeated skin exposure to metaldehyde may result in dermatitis (skin
inflammation) in humans. Prolonged eye exposure can cause conjunctivitis.
In 2-year toxicity studies and three-generation reproductive studies
in rats, changes in liver enzyme activity and increased liver and ovary
weight at dietary doses of about 12.5 mg/kg/day were found; 50% of female
rats given this dose showed paralysis. Effects on the brain (e.g., impairment
of memory) may also be possible with chronic exposure at very high levels.
- Reproductive effects: During a three-generation
study of rats exposed to chronic ingestion of metaldehyde, adverse effects
were seen on reproduction and on the survival rate of offspring. Doses
of 50 and 250 mg/kg/day interfered with the reproduction of female rats
in another three-generation test. These data suggest that metaldehyde
is likely to cause reproductive effects only at high levels. However,
the World Health Organisation says; A three generation
reproduction study with Wistar rats receiving, 1000 or 5000 mg/kg diet
demonstrated an adverse effect on reproduction. Hind-limb paralysis
and mortality were observed in females of all generations (including
parental) receiving 5000 mg/kg diet. A low incidence of hind-limb paralysis
was observed in the females of the F1 and F2 generations at 1000 mg/kg
diet. Fertility, viability and lactation indices were reduced in all
generations at the top dose. The onset of maternal hind-limb paralysis
at or about delivery had an adverse effect on the latter two parameters.
Increased relative liver weights were observed in some offspring.
- Teratogenic effects: Dietary doses
of 10, 50, and 250 mg/kg of metaldehyde were not teratogenic in three
generations of experimental female rats. There were some increases in
relative liver weights in some offspring. This evidence suggests that
metaldehyde is unlikely to cause teratogenic effects.
- Mutagenic effects: Metaldehyde has
been reported to be a suspected mutagen. However, there was no evidence
of mutagenicity when metaldehyde was tested on five strains of bacteria.
The evidence regarding mutagenicity of metaldehyde is inconclusive.
The following relationships between clinical effects and
ingested dose have been suggested: salivation, facial flushing, fever,
abdominal cramps, nausea, and vomiting from a "few" mg/kg; drowsiness,
tachycardia, spasms, irritability, salivation, abdominal cramps, facial
flushing, and nausea from up to 50 mg/kg; ataxia and increased muscle
tone from 50-100 mg/kg, convulsions, tremor, and hyperreflexia from 100-200
mg/kg; and coma and death from about 400 mg/kg.
Several incidents of metaldehyde exposure are reported
in literature. Ingestion of slug-bait pellets by children accounts for
the majority of the incidents reported in the United States of America
between 1966-1980. In Europe, human poisonings are also associated with
voluntary ingestion of tablets intended for use as fuel. Appearance of
symptoms might be delayed a few hours after ingestion. Survivors of severe
poisoning showed loss of memory which lasted for up to a year. Laboratory
findings included acid urine despite alkali therapy and elevated serum
transaminase activities. At autopsy, the main findings were fatty degeneration
with zonal necrosis of the liver and swelling and desquamation of the
renal tubular epithelium.
on birds: Death of birds feeding in metaldehyde-treated areas
has been reported, although the precise acute oral LD50 values or subchronic
dietary LC50 values were unavailable. Excitability, tremors, muscle spasms,
diarrhea, and difficult or rapid breathing was observed in poultry that
were exposed to metaldehyde.
on aquatic organisms: Metaldehyde is reported to be practically
nontoxic to aquatic organisms.
on other organisms: The 4% pelleted bait is reported to be toxic
to wildlife. When used as directed, bait agents with 6% active ingredient
are not toxic to bees. Bait pellets containing metaldehyde are attractive
to dogs. Pets should be confined during application, and kept away from
application and storage sites.
in soil and groundwater: Metaldehyde is
of low persistence in the soil environment, with a half-life on the order
of several days. It is weakly sorbed by soil organic matter and clay particles,
and is soluble in water. Due to its low persistence, it is not a significant
risk to groundwater.
- Breakdown in water: Metaldehyde undergoes
rapid hydrolysis to acetaldehyde, and should be of low perstistence in
the aquatic environment.
- Breakdown in vegetation: Many types
of flowers lose their color when they come in contact with metaldehyde
dust or spray.