Toxic dose-low

The lowest dose reported to produce any toxic effect (toxic dose low). 

Value is toxic dose low. TD q, the lowest dose of a substance introduced by any route other than inhalation, over any given period of time to which humans or animals have been exposed and reported to produce any nonsignificant toxic effect in humans or to produce nonsignificant tiimorigenic or reproductive effects in animals or humans. 

TDLo/Toxic Dose Low—The lowest dose introduced by any route other than inhalation over any period of time that produces any toxic effect in humans or that produces carcinogenic, teratogenic, mutagenic, or neoplastic effects in humans and animals. 

Toxic Dose Low. The lowest dose used in the study that caused any toxic effect (not just death) when administered by a route of entry other than inhalation. 

THA Toxic dose low. Lowest administered dose of a material capable of producing a defined toxic effect in a specific test species. 

Of the other Strychnos alkaloids vomicine has been investigated by Ruickoldt, who finds that in mice and rabbits it causes clonic convulsions, due to stimulation above the level of the anterior corpore quad-ragemina. Convulsions can be elicited after intravenous, but not after subcutaneous, injections. The toxicity is low twelve times the convulsive dose does not cause death. No special action is exerted on blood... 

Toxicity and Hazards. The odor cf ozone can be detected in concn as low as several parts per hundred million by vol (pphm). The threshold limit value (TLV) is O.lppmor 0.2mg/m3 its toxic dose level (TDL), 50% kill concn is 2ppm (Ref 6) Pure 100% liq ozone may be kept safely at 90°K (cooled by liq oxygen) for indefinite periods of time, but the smallest provocation, such as a spark or fast warming, even only up to bp (161°K), causes detonation. The evapn of liq ozone, for example, in the process of the prepn of pure gaseous ozone is, therefore, a dangerous procedure (Ref 3, p 224)... 

Figure 2-13 Two toxicants with differing relative toxicities at different doses. Toxicant A is more toxic at high doses, whereas toxicant B is more toxic at low doses.

DETAILS - Colchicine is a plant drug used in the treatment of gout. It is a very efficient poison in view of its very low toxic dose and the fact that an autopsy will show only the symptoms of acute gastroenteritis. This does not, however, mean it is undetectable. It only means that it is likely to be overlooked. It is also very useful as a dart poison, especially when nicotine is used as a binder. Colchicine is great for small caliber (,22)bullets, as they usually won t hold enough of most other poisons to do any good. It dissolves slowly in water, but faster in dilute ethanol (liquor). As with any plant alkaloid, it is best to harvest the... 

HANDLING - Avoid inhalation or mgest ion. Extremely low toxic dose. 

Low doses of nicotine stimulate respiration through activation of chemoreceptors in the aortic arch and carotid bodies, while high doses directly stimulate the respiratory centers. In toxic doses, nicotine depresses respiration by inhibiting the respiratory centers in the brainstem and by a complex action at the receptors at the neuromuscular junction of the respiratory muscles. At these neuromuscular receptors, nicotine appears to occupy the receptors, and the end plate is depolarized. After this, the muscle accommodates and relaxes. These central and peripheral effects paralyze the respiratory muscles. 

Morgan SL, Baggott IE, Vaughn WH et al. The effect of folic acid supplementation on the toxicity of low-dose methotrexate in patients with rheumatoid axthiitis. Arthritis Rheum 1990 33 9-18. 

Acute, Intermediate and Chronic-Duration Exposures. Inhalation exposures in both humans and laboratory animals predominate in the available information on acute, intermediate, and chronic effects of HDl, and will be considered here as a group. Information on laboratory animals describes the direct irritant effects of HDl, which was usually inhaled in large doses (>4 ppm) however, no information on the allergic component of HDl toxicity at low doses, the type of dose most commonly encountered in humans, was provided. Information on acute inhalation exposure of humans may be misleading. In most cases of acute exposure, the workers had been exposed to HDl and HDl prepolymers in their workplace for several months or several years (doses often not available). These workers were then tested with a small dose of either HDl or a product containing HDl with the HDl prepolymers and other organics. 

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