Metaldehyde

30.03

176.105

200-836-8

4CI033VJYG

1332

DTXSID1034715

Crystalline powder|Crystals

29125000

36.9

0.12

powder

1.27 at 20 deg C

165 °C

115 deg C (sublimes)

50 °C

1.385

In water, 222 mg/L at 20 deg C

0-6°C

6.6X10+3 mPa (5.0X10-2 mm Hg) at 25 deg C

Acute oral LD50 for dogs 0.6–1.0 g/kg (Worthing and Hance, 1991).

Menthol odor

Henry's Law constant = 5.22X10-5 atm-cu m/mol at 25 °C (est)

Depolymerization of metaldehyde to acetaldehyde begins at 80 °C and is complete above 200 °C.|Flammable solid|Molecular weight is variable; physical form: tetragonal needles or prisms (from alcohol); melting point: 246 °C; boiling point: 115 (sublimes); insoluble in water, acetone; slightly soluble in ethanol, diethyl ether, benzene, chloroform /Polymer/|Molecular weights in the range of 800,000 to 3,000,000 have been reported. Polyacetaldehyde is unstable and depolymerizes in a few days to acetaldehyde. /Polymer/|Rubber-like consistency. Soluble in common organic solvents. Depolymerizes at room temperature. /Polymer/|For more Other Experimental Properties (Complete) data for Metaldehyde (6 total), please visit the HSDB record page.

Highly flammable. Insoluble in water.

Ethers

Highly Flammable

METALDEHYDE is an ether derivative. The ether being relatively unreactive. Flammable and/or toxic gases are generated by the combination of alcohols with alkali metals, nitrides, and strong reducing agents. They react with oxoacids and carboxylic acids to form esters plus water. Oxidizing agents convert alcohols to aldehydes or ketones.

3370 kJ/mol

III

4.1

UN 1332 4.1/PG 3

1

10-22-23-11

13-23-46-45

AB3042000

Xn,T,F

Depolymerization occurs slowly on heating, and rapidly above 80 deg C.

P210-P260-P284-P301 + P310-P310

H228-H301-H330

SRP: Criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.|Do not discharge effluent containing this product into lakes, streams, ponds, estuaries, oceans, or other waters unless in accordance with the requirements of a National Pollution Discharge Elimination System (NPDES) permit and the permitting authority has been notified in writing prior to discharge. Do not discharge effluent containing this product to sewer systems without previously notifying the local sewage treatment plant authority. For guidance contact your State Water Board or Regional Office of the EPA.|Care must be taken to ensure that water sources are not contaminated. If the empty containers are burned, care must be taken to ensure that flammable residues do not cause an uncontrolled reaction. Containers may be decontaminated ..., but decontaminated containers must not be used for the transportation of food or drink.|Metaldehyde is flammable; where burning is recommended care must be taken to ensure that the operation remains controlled at all times.|For more Disposal Methods (Complete) data for Metaldehyde (6 total), please visit the HSDB record page.

Can react with oxidizing materials.

IPCS; Poisons Information Monograph 332: Metaldehyde (June, 1990). Poisons Information Monographs (PIM) are a global database with evaluated information on substances commonly involved in cases of poisoning.[Available from, as of October 9, 2009: http://www.inchem.org/pages/pims.html]|USEPA/Office of Pesticide Programs; Reregistration Eligibility Decision Document - Metaldehyde. OPP-2005-0231 (July 27, 2006). The RED summarizes the risk assessment conclusions and outlines any risk reduction measures necessary for the pesticide to continue to be registered in the U.S.[Available from, as of October 7, 2009: http://www.epa.gov/pesticides/reregistration/status.htm]

Excerpt from ERG Guide 133 [Flammable Solids]: Flammable/combustible material. May be ignited by friction, heat, sparks or flames. Some may burn rapidly with flare-burning effect. Powders, dusts, shavings, borings, turnings or cuttings may explode or burn with explosive violence. Substance may be transported in a molten form at a temperature that may be above its flash point. May re-ignite after fire is extinguished. (ERG, 2016)|Flammable - 3rd degree, Reactive - 1st degree

|Warning|H228: Flammable solid [Danger Flammable solids]|P210, P240, P241, P264, P270, P280, P301+P312, P330, P370+P378, and P501|Danger|H228 (100%): Flammable solid [Danger Flammable solids]|P210, P240, P241, P260, P264, P270, P271, P280, P284, P301+P310, P304+P340, P310, P320, P321, P330, P370+P378, P403+P233, P405, and P501|Aggregated GHS information provided by 38 companies from 1 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|P201, P202, P210, P240, P241, P264, P270, P273, P280, P281, P301+P310, P302+P352, P308+P313, P312, P321, P322, P330, P363, P370+P378, P405, and P501|Aggregated GHS information provided by 255 companies from 11 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|P201, P202, P210, P240, P241, P264, P270, P273, P280, P281, P301+P310, P308+P313, P321, P330, P370+P378, P405, and P501|P210, P240, P241, P260, P264, P270, P280, P301+P310, P305+P351+P338, P307+P311, P314, P321, P330, P337+P313, P370+P378, P405, and P501

Excerpt from ERG Guide 133 [Flammable Solids]: As an immediate precautionary measure, isolate spill or leak area for at least 25 meters (75 feet) in all directions. LARGE SPILL: Consider initial downwind evacuation for at least 100 meters (330 feet). FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)

Excerpt from ERG Guide 133 [Flammable Solids]: ELIMINATE all ignition sources (no smoking, flares, sparks or flames in immediate area). Do not touch or walk through spilled material. SMALL DRY SPILL: With clean shovel, place material into clean, dry container and cover loosely; move containers from spill area. LARGE SPILL: Wet down with water and dike for later disposal. Prevent entry into waterways, sewers, basements or confined areas. (ERG, 2016)

Excerpt from ERG Guide 133 [Flammable Solids]: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection. (ERG, 2016)|Mixers, loaders, applicators, and other handlers must wear long-sleeved shirts and long pants, and shoes plus socks.|Do not enter or allow worker entry into treated areas during the restricted entry interval (REI) of 12 hours. Exception: if the product is soil-injected or soil-incorporated, the Worker Protection Standard, under certain circumstances, allows workers to enter the treated areas without restriction if there will be no contact with anything that has been treated.|PPE required for early entry to treated areas that is permitted under the Worker Protection Standard and that involves contact with anything that has been treated, such as plants, soil, or water, is coveralls, shoes plus socks, and chemical-resistant gloves made of any waterproof material.|Personnel protection: ... Wear appropriate chemical protective gloves, boots, and goggles. ...

Moderate when exposed to heat or flame; can react with oxidizing materials.|It is highly flammable and when ignited will give off irritating fumes.|The polymer is so flammable that it is used as a fuel.

If material on fire or involved in fire: Solid streams of water may spread fire. Use water in flooding quantities as fog. Use dry chemical, graphite, or dry earth.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.|Spillage of liquid formulations should be contained with adsorbent material. This material, or spillage of dry formulations, should be collected and burned or buried in a deep pit. Residual contamination should be removed from the spillage site by washing with water and detergent.|If a spill occurs, clean it up promptly. Don't wash it away. Instead, sprinkle the spill with sawdust, vermiculite, or kitty litter. Sweep it into a plastic garbage bag, and dispose of it as directed on the pesticide product label.|After Applying a Pesticide, Indoors or Outdoors. To remove pesticide residues, use a bucket to rinse tools or equipment three times, including any containers or utensils that you used when mixing the pesticide. Then pour the rinsewater into the pesticide sprayer and reuse the solution by applying it according to the pesticide product label directions. After applying any pesticide wash your hands and any other parts of your body that may have come in contact with the pesticide. To prevent tracking pesticides inside, remove or rinse your boots or shoes before entering your home. Wash any clothes that have been exposed to a lot of pesticide separately from your regular wash.

SRP: Contaminated protective clothing should be segregated in a manner that results in no direct personal contact by personnel who handle, dispose of, or clean the clothing. Quality assurance procedures to confirm the efficacy of the cleaning procedures should be implemented prior to the decontaminated protective clothing being returned for reuse by the workers. Contaminated clothing (including shoes/socks) should not be taken home at end of shift, but should remain at employee's place of work for cleaning.|If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers.|Personnel protection: Avoid breathing dusts and fumes from burning material. Avoid bodily contact with the material. ... Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water.|If you suspect your pet has eaten metaldehyde slug bait, consider seeking veterinary care as soon as possible. Signs of poisoning may occur within a few minutes or up to three hours after ingestion. Timely treatment could save your pet's life.|For more Preventive Measures (Complete) data for Metaldehyde (20 total), please visit the HSDB record page.

/GUIDE 133: FLAMMABLE SOLIDS/ Fire or Explosion: Flammable/combustible material. May be ignited by friction, heat, sparks or flames. Some may burn rapidly with flare burning effect. Powders, dusts, shavings, borings, turnings or cuttings may explode or burn with explosive violence. Substance may be transported in a molten form at a temperature that may be above its flash point. May re-ignite after fire is extinguished.|/GUIDE 133: FLAMMABLE SOLIDS/ Health: Fire may produce irritating and/or toxic gases. Contact may cause burns to skin and eyes. Contact with molten substance may cause severe burns to skin and eyes. Runoff from fire control may cause pollution.|/GUIDE 133: FLAMMABLE SOLIDS/ Public Safety: CALL Emergency Response Telephone Number ... As an immediate precautionary measure, isolate spill or leak area for at least 25 meters (75 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Keep out of low areas.|/GUIDE 133: FLAMMABLE SOLIDS/ Protection Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection.|For more DOT Emergency Guidelines (Complete) data for Metaldehyde (8 total), please visit the HSDB record page.

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./|The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.|The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.

... very irritating to skin and eyes. ...

| 3 - Materials that, under emergency conditions, can cause serious or permanent injury.| 3 - Liquids and solids that can be ignited under almost all ambient temperature conditions. Materials produce hazardous atmospheres with air under almost all ambient temperatures or, though unaffected by ambient temperatures, are readily ignited under almost all conditions.| 1 - Materials that in themselves are normally stable but that can become unstable at elevated temperatures and pressures.

In mice intraperitoneal administration of 10 mg/kg bw diazepam or 0.5 mg/kg clonidine hydrochloride decreased the toxicity of an oral dose of 100 mg metaldehyde/kg bw administered 20 min previously. A dose of 0.5 mg diazepam/kg bw was without protective effect.

Acute oral lethal dose ... (in mg/kg) ... human being, 100.|The relation between the dose ingested and the clinical consequences is: trace (few): salivation, facial flushing, fever, abdominal cramps, nausea, vomiting; up to 50 mg/kg: drowsiness, tachycardia, spasms, irritability, salivation, abdominal cramps, facial flushing, nausea; 50 to 100 mg/kg: ataxia, increased muscle tone; 100 to 150 mg/kg: convulsions, tremor, hyperreflexia; 150 to 200 mg/kg: muscle twitching; 400 mg/kg: coma, death.

LD50 Rat oral 283 mg/kg|LD50 Rat oral 630 mg/kg|LD50 Rat (female) single oral dose 398 mg/kg|LD50 Rat dermal > 5000 mg/kg|For more Non-Human Toxicity Values (Complete) data for Metaldehyde (11 total), please visit the HSDB record page.

/BIRDS and MAMMALS/ A survey of mortality in hedgehogs (Erinaceus europaeus) was carried out between July 1976 and November 1986. Of the 74 examined, 35 (47.3 per cent) were road casualties ... Metaldehyde poisoning was diagnosed in three animals.|/BIRDS and MAMMALS/ Available data on the acute toxicity for terrestrial animals indicate that metaldehyde is moderately toxic to mammals and slightly to moderately toxic to birds on an acute exposure basis. For the chronic assessments, parental systemic toxicity and toxicity to offspring are identified as the endpoint for mammalian wildlife. For birds, the chronic endpoint is based on reproductive effects (reductions in the ratios of number hatched to eggs laid, to eggs set, and to live embryos; and reduction in the ratio of hatchling survival to eggs set), as observed in a study conducted with mallard ducks.|/AQUATIC SPECIES/ Molluscicide with stomach and contact action. Contact with the foot makes the mollusk torpid, and induces an increased secretion of mucus, leading to dehydration.|/FIELD STUDIES/ Over two years, six consecutive field experiments were done in which the chemical molluscicide metaldehyde and the nematode biocontrol agent Phasmarhabditis hermaphrodita (Schneider) were applied at the standard field rates to replicated mini-plots successively planted with lettuce, Brussels sprouts, leaf beet, and cabbage, to compare the effectiveness of different treatments in reducing slug damage to the crops. Soil samples from each plot were taken prior to the start of the experiments, and then monthly, to assess the populations of slugs, snails, earthworms, nematodes, acarids and collembolans. The experiments were done on the same site and each plot received the same treatment in the six experiments. The six treatments were: (1) untreated controls, (2) metaldehyde pellets, (3 and 4) nematodes applied to the planted area 3 days prior to planting without or with previous application of cow manure slurry, (5) nematodes applied to the area surrounding the planted area 3 days prior to planting, and (6) nematodes applied to the planted area once (only in the first of the six consecutive experiments). Only the metaldehyde treatment and the nematodes applied to the planted area at the beginning of each experiment without previous application of manure significantly reduced slug damage to the plants, and only metaldehyde reduced the number of slugs contaminating the harvested plants. The numbers of slugs, snails and earthworms in soil samples were compared among the six treatments tested: with respect to the untreated controls, the numbers of Deroceras reticulatum (Muller) were significantly affected only in the metaldehyde plots, and the numbers of Arion ater L only in the plots treated with nematodes applied to the planted area 3 days prior to planting without previous application of manure; numbers of snails (Ponentina ponentina (Morelet) and Oxychilus helveticus (Blum)) were not affected by the treatment. The total numbers of all earthworm species and of Lumbricus spp were unaffected by the treatment, but Dendrobaena spp increased significantly in the plots treated with manure. The numbers of nematodes, acarids and collembolans in soil samples were compared between the untreated controls and the treatments with nematodes applied 3 days prior to planting to the planted area or to the surrounding area, without previous application of manure: the treatment had a significant effect on the number of nematodes in soil samples, but acarids and collembolans were unaffected.

The domestic uses of metaldehyde will allow potential exposure for a large population. The lower concentration of metaldehyde in domestic formulations reduces the risk, but users must still protect against deliberate ingestion by children, pets and domestic animals.|Occupationally exposed populations: gardeners

Metaldehyde's production may result in its release to the environment through various waste streams; its use as a molluscicide(1) will result in its direct release to the environment(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), a measured Koc value of 240(2) indicates that metaldehyde is expected to have moderate mobility in soil(SRC). Volatilization of metaldehyde from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 5.2X10-5 atm-cu m/mole(SRC), derived from its vapor pressure, 5.0X10-2 mm Hg(2), and water solubility, 2.22X10+2 mg/L(2). Metaldehyde is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(2). The results of a laboratory volatility study suggest that volatilization losses from soil surfaces will be minor(3). In a field study, 6% metaldehyde pellets were broadcast at the rate of 4 kg product/ha in a rice paddy ecosystem(4). Paddy soil samples collected 3 to 14 days after application had metaldehyde residue concentrations ranging from 0.053 to 0.127 mg/kg, reaching a peak at 0.127 mg/kg 14 days after application(4). Metaldehyde residue was below the minimum detection limit of 0.016 mg/kg 22 days after application(4). A reported half-life of approximately 2 months for metaldehyde in soil(3) suggests that biodegradation is not an important environmental fate process in soil(SRC). In soil, microbiological decomposition of metaldehyde to carbon dioxide and water occurs(2).|AQUATIC FATE: Based on a classification scheme(1), a measured Koc value of 240(2) indicates that metaldehyde is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 5.2X10-5 atm-cu m/mole(SRC), derived from its vapor pressure, 5.0X10-2 mm Hg(2), and water solubility, 2.22X10+2 mg/L(2). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 26 hours and 12 days, respectively(SRC). In a field study, 6% metaldehyde pellets were broadcast at the rate of 4 kg product/ha in a rice paddy ecosystem(4). Paddy water samples collected 1 to 3 days after application had metaldehyde residue concentrations of 1.58 to 1.47 mg/L(4). Residues could be detected only up to 9 days after application, with its degradation pattern following pseudo first-order kinetics showing a half-life of 0.27 days(4). According to a classification scheme(5), an estimated BCF of 3.2(SRC), from its log Kow(2) and a regression-derived equation(6), suggests the potential for bioconcentration in aquatic organisms is low. Utilizing the Japanese MITI test, a 0% of theoretical BOD in four weeks(7) suggests that biodegradation is not an important environmental fate process in water(SRC).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), metaldehyde, which has a vapor pressure of 5.0X10-2 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase metaldehyde is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 13 hours(SRC), calculated from its rate constant of 2.9X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Metaldehyde does not contain chromophores that absorb at wavelengths >290 nm(4) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

The rate constant for the vapor-phase reaction of metaldehyde with photochemically-produced hydroxyl radicals has been estimated as 2.9X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 13 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Metaldehyde is expected to undergo hydrolysis in the environment since this compound contains functional groups that hydrolyze under environmental conditions(2). Metaldehyde does not contain chromophores that absorb at wavelengths >290 nm(2) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

An estimated BCF of 3.2 was calculated for metaldehyde(SRC), using a log Kow of 0.12(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

239.88 L/kg|The Koc of metaldehye is measured as 240(1). According to a classification scheme(2), this Koc value suggests that metaldehyde is expected to have moderate mobility in soil.

The Henry's Law constant for metaldehyde is estimated as 5.2X10-5 atm-cu m/mole(SRC) derived from its vapor pressure, 5.0X10-2 mm Hg(1), and water solubility, 2.22X10+2 mg/L(1). This Henry's Law constant indicates that metaldehyde is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 26 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 12 days(SRC). Metaldehyde's estimated Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Metaldehyde is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1). The results of a laboratory volatility study suggest that volatilization losses from soil surfaces will be minor(3).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 5,445 workers (588 of these were female) were potentially exposed to metaldehyde in the US(1). The NOES Survey does not include farm workers. Occupational exposure to metaldehyde may occur through inhalation of dust and dermal contact with this compound at workplaces where metaldehyde is produced or used(SRC). The general population can be exposed to metaldehyde via dermal contact when used as a molluscicide as a result of both application and post-application activities, on a short term exposure basis(2).|A review of data from the American Association of Poison Control Centers shows that a total of 1648 poisoning incidents in children were recorded for metaldehyde in the years 1993 to 2003. The most recent year for which data are available is 2004, when 244 accidental exposures to metaldehyde were reported, with 105 incidents occurring in children younger than 6 years old(1).|MOLLUSCICIDE METALDEHYDE IS USED IN CALFORNIA CITRUS GROVES TO SUPPRESS POPULATIONS OF BROWN GARDEN SNAIL. AFTER 56-HA SOIL BROADCAST APPLICATIN OF 7.5% ACTIVE INGREDIENT GRANULAR FORMULATION, 3-DAY RIND SAMPLES SHOWED A MAX RESIDUE LEVEL OF 0.02 PPM. THE 10- AND 17-DAY RIND SAMPLES AND 10-DAY PULP (EDIBLE PORTION) SAMPLES CONTAINED GREATER THAN 0.01 PPM.|...EMITTED VAPORS /FROM METALDEHYDE USED AS A FUEL/ ARE ALSO SOURCE OF POISONING IN SITUATIONS WHERE POOR VENTILATION EXISTS.

One patient died after ingesting 12 g (or 258.6 mg/kg) of metaldehyde.|The following relationships between clinical effects and ingested dose have been suggested: ... coma and death from about 400 mg/kg.|4. Probably lies near borderline between toxicity classes 3 and 4. 3 = moderately toxic: 0.5-5 g/kg, probable oral lethal dose (human), between 1 oz and 1 pint (or 1 lb) for 70 kg person (150 lb); 4 = very toxic: 50-500 mg/kg, probable oral lethal dose (human), between 1 tsp and 1 oz for 70 kg person (150 lb).|LD children = 2-3 g

Agents destructive to snails and other mollusks. (See all compounds classified as Molluscacides.)

Metaldehyde is readily absorbed from GI tract, probably as different sized fragments of acetaldehyde polymer ... These substances readily cross blood-brain barrier, as evidenced by their effect on level of consciousness.|Metaldehyde was found in the plasma & urine of dogs given a single oral dose of 600 mg/kg. The urinary excretion of metaldehyde was <1% of the dose.

Metaldehyde slowly hydrolyzes to acetaldehyde in acid solutions (i.e., in the stomach). Acetaldehyde is then oxidized to acetic acid. Acetaldehyde was not found in plasma and urine of metaldehyde treated dogs.|Ingestion of about 100 to 150 mg/kg of metaldehyde led to peak serum levels of metaldehyde (120 ug/mL) 35 hr after ingestion & urine levels of 53 ug/mL in 14 hr. Acetaldehyde levels in the serum were <1.0 ug/mL.

The urinary excretion of metaldehyde was less than 1% of the dose ... Elimination half-life is 27 hr.

The toxicologically active substance in metaldehyde intoxication is mainly the degradation product acetaldehyde, which is formed at a low pH in the stomach. Other toxic products are probably also formed. Acetaldehyde acts as a releasing factor for 5-hydroxytryptamine (5-HT) and noradrenaline (NA). It also competitively inhibits biogenic amine oxidation which, in turn, decreases 5-hydroxyindoleacetic acid (5-HIAA), a metabolite of 5-HT by competitively inhibiting 5-HT-oxidation. Acetaldehyde also increases monoamine oxidase activity and decreases central serotonin levels ...|Its pesticidal action is due to contact with the foot of the mollusk, making it torpid and increasing the secretion of mucus leading to dehydration.

Excerpt from ERG Guide 133 [Flammable Solids]: Fire may produce irritating and/or toxic gases. Contact may cause burns to skin and eyes. Contact with molten substance may cause severe burns to skin and eyes. Runoff from fire control may cause pollution. (ERG, 2016)

Excerpt from ERG Guide 133 [Flammable Solids]: Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. Removal of solidified molten material from skin requires medical assistance. Keep victim calm and warm. (ERG, 2016)

Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Aldehydes and Related Compounds/|Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Aggressive airway management may be necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Anticipate seizures and treat if necessary ... . Monitor for shock and treat if necessary ... . Monitor for pulmonary edema and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . /Aldehydes and Related Compounds/|Advanced treatment: Consider Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Intubation should be considered at the first sign of upper airway obstruction caused by edema. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Consider vasopressors if patient is hypotensive with a normal fluid volume. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Aldehydes and Related Compounds/|/VET/ Treatment is most effective if initiated early. Further toxicant absorption should be prevented by induced emesis, gastric lavage, and oral dosing with activated charcoal. Hyperesthesia and muscle activity may be controlled with diazepam at 2-5 mg, lV, or light barbiturate anesthesia and muscle relaxants as needed. IV fluid therapy with lactated Ringer's solution or 5% glucose should be aggressive to promote toxin excretion and to combat dehydration and the acidosis induced by the excessive muscle activity. Continuous supportive care is important. Prognosis is heavily determined by the exposure dose, but if death does not occur earlier, animals poisoned by metaldehyde may show clinical improvement 24-36 hr after initial onset of signs.|For more Antidote and Emergency Treatment (Complete) data for Metaldehyde (7 total), please visit the HSDB record page.

/SIGNS AND SYMPTOMS/ Symptoms generally occur within 3 hours (although they have been delayed up to 48 hours and include salivation, lethargy, abdominal pain, nausea, vomiting, and diarrhea, progressing to seizures, hyperthermia, comas, and death. inhalation produces mucous membrane irritation, and inhaling pyrolized metaldehyde has caused noncardiogenic pulmonary edema. Memory loss and cognitive dysfunction have been reported after severe poisoning.|/SIGNS AND SYMPTOMS/ Potential symptoms of overexposure by ingestion are severe abdominal pain, nausea, vomiting, diarrhea, convulsions, coma.[The Merck Index, Fourteenth Edition (2006)|/SIGNS AND SYMPTOMS/ 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.|/SIGNS AND SYMPTOMS/ 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.|For more Human Toxicity Excerpts (Complete) data for Metaldehyde (19 total), please visit the HSDB record page.

metacetaldehyde

Corry's Slug, Snail & Insect Killer, Get-A-Bug Snail, Slug & Insect Killer : Active ingredients 2.0%Metaldehyde, 5.0% Carbaryl|Bug-Geta Snail & Slug Pellets: Active ingredient 3.25% Metaldehyde|Durham Metaldehyde Granules 3.5: Active ingredient 3.5% Metaldehyde|Corry's Liquid Slug & Snail Control, Deadline Bullets, Deadline M-PS Mini-Pellets!, Metaldehyde 4 Bait, Metarex 4% Snail And Slug Bait: Active ingredient 4.0% Metaldehyde|For more Formulations/Preparations (Complete) data for Metaldehyde (29 total), please visit the HSDB record page.

Acetaldehyde, homopolymer: ACTIVE|XU - indicates a substance exempt from reporting under the Chemical Data Reporting Rule, (40 CFR 711).|The WHO Recommended Classification of Pesticides by Hazard identifies Metaldehyde (technical grade) as Class II: moderately hazardous; Main Use: molluscicide.

PRODUCT ANALYSIS...IS BY HYDROLYSIS, DISTILLING THE ACETALDEHYDE INTO AQ SODIUM SULFITE, TREATING ADDUCT WITH SODIUM HYDROGEN CARBONATE & ESTIMATING LIBERATED SULFITE BY TITRATION WITH IODINE (CIPAC HANDBOOK, 1970, 1, 532) OR BY HEATING WITH HYDROXYLAMINE HYDROCHLORIDE & TITRATING THE LIBERATED ACID WITH ALKALI (MAFF TECH BULL, NUMBER 1, 1958, P 58).|DETECTION IN BAITS: WARM GENTLY IN TEST TUBE, METALDEHYDE SUBLIMES FORMING COPIOUS "ARTIFICIAL SNOW". ... MICRO: STRIP WITH CHLOROFORM, WASH WITH 2% SODIUM BISULFITE TO REMOVE FREE ALDEHYDE, STEAM DISTILL FROM ACID & ESTIMATE ACETALDEHYDE BY STOTZ'S METHOD (GIANG, PA & SMITH, EF, TECH BULL MINIST AGRIC 1, 58, 1958).

A method was developed to detect metaldehyde in samples of stomach contents. Gas chromatography-ion trap mass spectrometry in full-scan mode was used to identify and quantify metaldehyde. The limit of detection based on mass chromatograms for the m/z 89 ion was 3 ug/g. Mean recoveries from six different spiked samples were 74% at 25 ug/g and 94% at 500 ug/g. The relative standard deviation of six replicate determinations of a sample containing 632 ug/g metaldehyde was 7.3%.

Agrochemicals -> Molluscicides|Fire Hazards -> Flammable - 3rd degree, Reactive - 1st degree|Molluscicides|Environmental transformation -> Pesticides (parent, predecessor)

Metaldehyde has known environmental transformation products that include Paraldehyde.