Toxicity constitutes

Indications of embryo or fetal toxicity include increased incidence of embryonic or fetal resorptions, reduced or increased weight or size of the fetuses, and delayed fetal development and dysmorphogenesis. Any of these findings in the absence of maternal toxicity constitute evidence of selective developmental toxicity. Abortion in rabbits is a frequent consequence of maternal toxicity, but may also occur as the result of a compound-induced embryo-fetal mortality. 

Lithium toxicity constitutes a medical emergency. Because the need for early recognition and treatment are essential, its manifestations are included in Table 3.22 for reference. 

Human Toxicity Constitutes a hazard when ingested ... 

Risk is a function of the body burden and the inherent toxicity of the material ( 1 ). Clearly, Botulinum toxin, which is an extremely hazardous toxicant, constitutes no risk when body burdens are zero. Body burden may be best illustrated in kinetic terms, as shown graphically in Figure 1. 

This article has been reviewed by the Office of Pollution Prevention and Toxics (U.S. EPA) and approved for pubHcation. Approval does not signify that the contents necessarily reflect the views and poHcies of the Agency, nor does mention of commercial products constitute endorsement or recommendation for use. 

Health and Safety Factors. Isophthahc acid has a low order of toxicity. Inhalation by rats for 4 h at 11.4 g/m showed no toxicity. The LD -level for rats is high at 10.4 g/kg (96). As with terephthahc acid, isophthahc acid was found to form urinary tract calcuh in rats in 90 d when it constituted 3% of their diet. This led to some cancer owing to the presence of the calcuh. Some mild eye irritation is possible, so eye protection should be worn. Otherwise, normal precautions used in handling industrial chemicals should be observed with isophthahc acid. 

Industrial refractories are by thek very nature stable materials and usually do not constitute a physiological hazard. This is not so, however, for unusual refractories that might contain heavy metals or radioactive oxides, such as thoria and urania, or to bkiders or additives that may be toxic. 

Toxicity. The acceptable daily allowance, which may be ingested without any risk of harm, is 1050 mg for a 70-kg healthy person (20). There is also no evidence in the Hterature that ingestion of up to 10 g vitamin C per day constitutes a serious health risk for humans. 

Although biphenyl and the terphenyls fall under the ha2ardous chemical criteria of the OSHA Ha2ard Communications Standard, the products themselves are fairly low in toxicity and do not constitute a serious industrial ha2ard. Some relevant exposure and toxicity data are summari2ed in Tables 5 and 6. 

Carbon tetrachloride is toxic by inhalation of its vapor and oral intake of the Hquid. Inhalation of the vapor constitutes the principal ha2ard. Exposure to excessive levels of vapor is characterized by two types of response an anesthetic effect similar to that caused by compounds such as diethyl ether and chloroform and organic injury to the tissues of certain organs, in particular the Hver and kidneys. This type of injury may not become evident until 1—10 days after exposure. The nature of the effect is deterrnined largely by the vapor concentration but the extent or severity of the effect is deterrnined principaHy by the duration of exposure (38). 

Class A—immediately dangerous to life and health based on oxygen level less than 19.5 percent and/or airborne presence of toxic or poisonous substances in concentration constituting IDLH conditions flammabihty up to 20 percent of lower flammable limit. 

Submission of EPA Form R. the Toxic Chemical Release Inventory Reporting Form, Is required by section 313 of the Emergency Planning and Community RIght-to-Know Act (Title III of the Superfund Amendments and Reauthoiizatlon Act of 1986), Public Law 99-499. The Information contained in Form R constitutes a report, and the submission of a report to the appropriate authorities constitutes reporting. ... 

A completed Form R must be submitted for each toxic chemical manufactured, processed, or otherwise used at each covered facility as prescribed in the reporting rule in 40 CFR Part 372 (published February 16,1988 in the Federal Register). These instructions supplement and elaborate on the requirements In the reporting rule. Together with the reporting rule, they constitute the reporting requirements. All references in these instructions are to sections in the reporting rule unless otherwise indicated. 

The traditional safety engineering approach to accident causation focuses on the individual rather than the system causes of error. Errors are primarily seen as being due to causes such as lack of motivation to behave safely, lack of discipline or lack of knowledge of what constitutes safe behavior. These are assumed to give rise to "unsafe acts." These unsafe acts, in combination with "unsafe situations" (e.g., imguarded plant, toxic substances) are seen as the major causes of accidents. 

The reader should note tliat since many risk assessments have been conducted on the basis of fatal effects, there are also uncertainties on precisely what constitutes a fatal dose of thennal radiation, blast effect, or a toxic chemical. Where it is desired to estimate injuries as well as fatalities, tlie consequence calculation can be repeated using lower intensities of exposure leading to injury rather titan dcatli. In addition, if the adverse healtli effect (e.g. associated with a chemical release) is delayed, the cause may not be obvious. Tliis applies to both chronic and acute emissions and exposures. 

Herbicides constitute a large and diverse class of pesticides that, with a few exceptions, have very low mammalian toxicity and have received relatively little attention as environmental pollutants. Much of the work in the held of ecotoxicology and much environmental risk assessment has focused on animals, especially vertebrate animals. There has perhaps been a tendency to overlook the importance of plants in the natural world. Most plants belong to the lowest trophic levels of ecosystems, and animals in higher trophic levels are absolutely dependent on them for their survival. 

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