Inherent toxicity

Human exposure to certain plasticizers has been debated because di-(2-ethylhexyl) phthalate (DOP), used in medical plastics, has been found at detectable levels in the blood supply and potential health risks may arise from its chronic exposure. A further issue is the use of phthalates in baby-care products and toys. Since yovmg children often put their plastic toys in the mouth, the plasticizers are prone to be leached out and can be swallowed (2). Research with animals revealed a possible endocrine-disruption activity (13). 

Benzoate based plasticizers, e.g., Benzoflex 2888 which is a blend of diethylene glycol dibenzoate, triethylene glycol dibenzoate, and dipropylene glycol dibenzoate, have been developed to account for the leaching problems. Benzoflex seems to be a good alternative to phthalates in flexible toys due to its ease of processing, final product performance, low toxicity and fast biodegradation. Toxicity tests showed a low acute toxicity and no evidence of reproductive toxicity (2). 

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Silver compounds having anions that are inherently toxic, eg, silver arsenate and silver cyanide, can cause adverse health effects. The reported rat oral LD values for silver nitrate, silver arsenate [13510-44-6] and silver cyanide are 500—800 (29), 200—400 (29), and 123 mg/kg (30), respectively. Silver compounds or complexes ia which the silver ion is not biologically available, eg, silver sulfide and silver thiosulfate complexes, are considered to be without adverse health effects and essentially nontoxic. 

In 1938 a new law, the Federal Food, Dmg, and Cosmetic Act of 1938 (18), which instituted several new and important practices, was enacted. Fkst, it clearly stated that, henceforth, the use of any uncertified coal-tar color in any food, dmg, or cosmetic shipped in interstate commerce was stricdy forbidden. This restriction appHed regardless of the inherent toxicity of the colorant. In effect, the colorants that could be used were limited, certification became mandatory, and governmental control was extended to the coloring of dmgs and cosmetics. Next, it created three categories of coal-tar colors ... 

Organic molecules thus far identified, such as those fisted above, appear either to have irreversible antifertifity effects, to be inherently toxic, or to affect libido. It has been demonstrated that sperm count could be depressed in men injected with large doses of androgens. However, questions about the potential utility of androgens as male antifertifity agents are stiU debated. 

Benchmark 4 Prefer - Safer Chemical. Only organic chemicals with low inherent toxicity to humans and wildlife, that do not bio accumulate, and rapidly and completely degrade to benign degradation products or metabolites reach Benchmark 4. These are chemicals that would meet the principles of green chemistry that relate to hazard. 

Most of the materials used in the manufacture of chemicals are poisonous, to some extent. The potential hazard will depend on the inherent toxicity of the material and the frequency and duration of any exposure. It is usual to distinguish between the short-term effects (acute) and the long-term effects (chronic). A highly toxic material that causes immediate injury, such as phosgene or chlorine, would be classified as a safety hazard. Whereas a material whose effect was only apparent after long exposure at low concentrations, for instance, carcinogenic materials, such as vinyl chloride, would be classified as industrial... 

The inherent toxicity of a material is measured by tests on animals. It is usually expressed as the lethal dose at which 50 per cent of the test animals are killed, the LD50 (lethal dose fifty) value. The dose is expressed as the quantity in milligrams of the toxic substance per kilogram of body weight of the test animal. 

It is a first principle of toxicology that no chemical substance is a poison at all concentrations toxicity occurs only when a critical concentration is reached within vital cells. Whether or not an economic poison will exert a particular deleterious effect depends on the relative rates of absorption as compared with detoxication and elimination, its inherent toxicity, and the physiologic status of the organism. 

This law, which is a criminal law, is so loosely worded that it is at the moment impossible to establish criteria for paints, varnishes, or lacquers to be placed on children s furniture or toys to be sold in Maryland. Further, the Maryland law has little protective value, since anyone can repaint children s furniture or toys with any material regardless of its suitability for the purpose and its inherent toxicity. This law, as it stands, places a heavy and complex burden on the manufacturer and marketer of children s toys and furniture—and necessarily on the manufacturer of paints, lacquers, and varnishes. The Maryland law has greater significance as a piece of troublesome legislation in that in the courts of the state of Maryland, the jury is the judge of the law as well as the facts under the law, and since under criminal law each case would be argued on its own merits, two different juries might reach contradictory decisions on the same set of circumstances. 

Polycationic polymers. These are macromolecules that have electropositive groups attached to the polymer chain or pendant to the chain. These materials are active against a number of bacteria and fungi. However, due to their inherent toxicity to animal species through their destructive interaction with cell membranes they are... 

The utility of such reagents in the oxidation processes is compromised due to their inherent toxicity, cumbersome preparation, potential danger in handling of metal complexes, difficulties encountered in product isolation and waste disposal problems. Immobilization of metallic reagents on solid supports has circumvented some of these drawbacks and provided an attractive alternative in organic synthesis because of the selectivity and associated ease of manipulation. Further, the localization of metals on the mineral oxide surfaces reduces the possibility of their leaching into the environment. 

The deployment of chromium(VI) reagents in the oxidative transformation is compromised due to inherent toxicity, involved preparation of its various complex forms (with pyridine or acetic acid) and cumbersome workup procedures. Chromium trioxide (Cr03) immobilized on premoistened alumina enables efficient oxidation of ben -... 

In evaluating the potential toxicity of airborne particles, it is important to consider where they will deposit in the respiratory tract, how long they can be expected to be retained there (or elsewhere in the body if the particles clear from the lungs) and the inherent toxicity of the particles. All of these considerations are determined by the physical and chemical characteristics of the particles. 

The inherent toxicity of the particle will depend on its chemical composition. For example, a particle of CdCl2 can be expected to be more toxic than NaCl because of the known toxicity of Cd+2 (6). In the case of fibrous particles, the toxicity of the material will also depend on the size and shape of the fibers, with long, thin fibers being the most toxic (7.8). 

Second, many of the particles produced, such as soot and metallic oxides, will have low solubility in the lung. Thus, once deposited, these particles will remain in the lung for long periods of time with a greater potential for exerting Whatever inherent toxicity they may have than would soluble particles (1.5). All of these factors roust be considered in evaluating the toxicity of particulate matter in smokes. 

In some instances it may be necessary to demonstrate that all traces of specific contaminants have been removed prior to final product filling. This would be true, for example, of many proteolytic inhibitors added during the initial stages of downstream processing to prevent proteolysis by endogenous proteases. Some such inhibitors may be inherently toxic, and many could (inappropriately) inhibit endogenous proteases of the recipient patient. 

Bucciantini, M., Giannoni, E., Chiti, F., Baroni, F., Formigli, L., Zurdo, J., Taddei, N., Ramponi, G., Dobson, C. M., and Stefani, M. (2002). Inherent toxicity of aggregates implies a common mechanism for protein misfolding diseases. Nature 416, 507-511. 

Under TSCA, EPA also will turn its attention to requiring additional up-front testing and other data development for certain categories of new substances that consistently lack data (in the PMN s), and which are known to be inherently toxic. The primary vehicle for these additional requirements will be the 5(b)(4) "risk list," although some 4 test rules also may be used. 

It is important to note the meaning of two terms used in connection with TSCA and the Sixth Amendment, because they often have different interpretations under the two laws. "Hazard" generally is used in the Sixth Amendment (and in other EEC directives) to mean what U.S. scientists and regulators often call "risk" — i.e. an assessment or evaluation that considers both the effects and exposures that are associated with particular substances. In this country, the term "hazard" usually refers to the inherent toxicity or effects of a substance, or to the unsafe characteristics of particular chemicals or products. The latter meaning is the one used... 

Independent of combustibility or reactivity, chemicals may exhibit hazardous properties that affect fire protection, in particular firefighting. Chemicals may be inherently toxic or radioactive. In either situation, potential exposure of smoke/gases to personnel from the burning of materials exhibiting these characteristics needs to be addressed. 

In general, the use of LOAEL/NOAEL ratios to estimate a NOAEL from a LOAEL is questionable as these ratios reflect more the applied intervals between the dose levels in the studies (dose spacing, which is dependent on the study design), rather than the steepness of the dose-response relationship, i.e., the inherent toxicity. It has also been pointed out that there is no guarantee whatsoever that at one dose interval lower (extrapolation from a LOAEL to a NOAEL), the effect would be statistically nonsignificant. 

Phase 1 Tolerability Safety Pharmacokinetics Pharmacodynamics Usually male healthy volunteers For inherently toxic compounds patients (e.g. anti-tumor agents)... 

The reactivity or inherent toxicity of chemical substances introduced together with CNT. They can be located inside nanotubes or attached to their external surface. This factor is related to the surface area-to-mass ratio of nanoparticles. The higher the ratio, the more likely is the negative impact. 

In insect control petroleum oils may be used largely in three ways. First, they may be used as adhesives in the formulation of sprays and dusts—when used in this manner the inherent toxicity of the oil is not of primary interest. Second, they may be used as solvents which serve as carriers for toxicants such as rotenone and pyrethrin— lly spray is an example of this type. Third, they may be used as the principal toxic agent as in the case of horticultural sprays. 

The types of anxious personalities cited above develop PBDS not because of any inherent toxic effect of the BZD but because of their psychological disorder. A characteristic symptom of a PBDS is the rapid onset of discomfort whenever the patient thinks he or she will be without the BZD or that its dose is being lowered. 

As has often been stated, the Pd- or Ni-catalyzed aryl-aryl coupling can be achieved by using organometals containing ten or so different metals, but it has been most extensively carried out with those containing B, Zn, Mg and Sn, although the inherent toxicity... 

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