Toxic dose, lethal

Toxicity. The lethal dose of Mgp2 to guinea pigs by ingestion is 1000 mg/kg (17). 

Health, Safety, and Environmental Factors. Sulfur dioxide has only a moderate acute toxicity (183). The lowest pubHshed human lethal concentration is 1000 ppm for 10 months. The lowest pubHshed human toxic concentration by inhalation is 3 ppm for 5 days or 12 ppm for 1 hour. The lowest pubHshed human lethal concentration is 3000 ppm for 5 months. In solution (as sulfurous acid), the lowest pubHshed toxic dose is 500 flg/kg causing gastrointestinal disturbances. Considerable data is available by other modes of exposure and to other species NIOSH standards are a time-weighted average of 2 ppm and a short-term exposure limit of 5 ppm (183). 

The threshold of a toxic dose in adult humans is about 0.2—0.5 g Ba the lethal dose in untreated cases is 3—4 g Ba, LD q about 66 mg/kg (47). The fatal dose of barium chloride for humans is reported to be between 0.8 and 0.9 g (0.55—0.60 g of Ba) (50). However, for most of the acid-soluble salts of barium, doses greater than 1 g have been tolerated (51). Lethal doses are summarized in Table 5. Dusts of barium oxide are considered potential dermal and nasal irritants (52). 

Vapors of both benzal chloride and benzotrichloride are strongly irritating and lacrimatory. Reported toxicides appear in Table 3. Also, for benzotnchlonde, the lowest pubflshed lethal dose (frog) is 2150 mg/kg (69) and the toxic dose level (inhalation rats) is 125 ppm/4 h (69). 

Because the minimal lethal or toxic dose of LSD is not well established, assessment ofseverity of intoxication should always be made on clinical grounds. The... 

Lethal and toxic doses LC (mg/I/duraiion of exposure) LD (mgAtg),... 

Toxicity Safely Code (Tr) NFPA Transport Code (TR> LVE (MVEI (ppra) F. USA, D Lethal and toxic doses LC (mg/l/duratron of expostue) LD (ingA g). 

Lethal and toxic doses LCfmgA/dmatioo of etqtosuielcLlXnig/kg). 

Despite the apparent promise for this line of research to explain caffeine s potential ergogenicity, the doses of caffeine necessary to produce significant calcium shifts are midway between toxic and lethal levels when transposed to in vitro situations.5 These dosage requirements suggest that the mobilization of intracellular calcium is not a viable explanation for caffeine s potential ergogenic effects in live human subjects. 

The most likely toxicity value to be found in the literature is the LD50 (dose lethal to 50% of the animals) for some laboratory species, usually rat or mouse. This value may be obtained by plotting on probit paper the fraction of experimental animals killed against the acute dosage. There Is seldom enough information to permit extrapolation to a dosage at which only a very small (e.g., 1%) fraction of the animals would be killed, much less to an acceptable risk level. Handy and Schindler (12), however, assum ... 

Acute-Duration Exposure. Information is available regarding the effects of acute-duration inhalation exposure of humans to acrylonitrile and the effects are characteristic of cyanide-type toxicity. Quantitative data are limited but are sufficient to derive an acute inhalation MRL. Further studies of humans exposed to low levels of acrylonitrile in the workplace would increase the confidence of the acute MRL. Studies in animals support and confirm these findings. No studies are available on the effects of acute-duration oral exposure in humans however, exposure to acrylonitrile reveals neurological disturbances characteristic of cyanide-type toxicity and lethal effects in rats and mice. Rats also develop birth defects. Animal data are sufficient to derive an acute oral MRL. Additional studies employing other species and various dose levels would be useful in confirming target tissues and determining thresholds for these effects. In humans, acrylonitrile causes irritation of the skin and eyes. No data are available on acute dermal exposures in animals. 

Figure 1. Categories of toxicity and lethal doses of various poisons and of the smoke from polymeric materials according to the NBS Cup Furnace Smoke Toxicity Protocol.

Figure 2-8 The various types of response vs. log dose curves. ED, effective dose TD, toxic dose LD, lethal dose. For gases, LC (lethal concentration) is used.

Finally, if the response to the agent is toxic (an undesirable response that is not lethal but is irreversible, such as liver or lung damage), the response-log dose curve is called the toxic dose, or TD curve. 

Experimental LDso per kilogram of body weight Degree of toxicity Probable lethal dose for a 70-kg person... 

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