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  2. Urea - Wikipedia

    en.wikipedia.org/wiki/Urea

    The structure of the molecule of urea is O=C(−NH 2) 2.The urea molecule is planar when in a solid crystal because of sp 2 hybridization of the N orbitals. [8] [9] It is non-planar with C 2 symmetry when in the gas phase [10] or in aqueous solution, [9] with C–N–H and H–N–H bond angles that are intermediate between the trigonal planar angle of 120° and the tetrahedral angle of 109.5°.

  3. Metabolic waste - Wikipedia

    en.wikipedia.org/wiki/Metabolic_waste

    The excretion of urea is called ureotelism. Land animals, mainly amphibians and mammals, convert ammonia into urea, a process which occurs in the liver and kidney. These animals are called ureotelic. [3] Urea is a less toxic compound than ammonia; two nitrogen atoms are eliminated through it and less water is needed for its excretion.

  4. EPA list of extremely hazardous substances - Wikipedia

    en.wikipedia.org/wiki/EPA_list_of_extremely...

    This is the list of extremely hazardous substances defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. § 11002). The list can be found as an appendix to 40 CFR 355. [1] Updates as of 2006 can be seen on the Federal Register, 71 FR 47121 (August 16, 2006). [2]

  5. Ureas - Wikipedia

    en.wikipedia.org/wiki/Ureas

    Biotin, a water-soluble B vitamin, is a bicyclic urea.. In chemistry, ureas are a class of organic compounds with the formula (R 2 N) 2 CO where R = H, alkyl, aryl, etc. Thus, in addition to describing the specific chemical compound urea ((H 2 N) 2 CO), urea is the name of a functional group that is found in many compounds and materials of both practical and theoretical interest.

  6. Chemical hazard - Wikipedia

    en.wikipedia.org/wiki/Chemical_hazard

    The use of personal protective equipment may substantially reduce the risk of adverse health effects from contact with hazardous materials. [2] Long-term exposure to chemical hazards such as silica dust, engine exhausts, tobacco smoke, and lead (among others) have been shown to increase risk of heart disease, stroke, and high blood pressure. [3]

  7. Organic matter - Wikipedia

    en.wikipedia.org/wiki/Organic_matter

    Organic matter, organic material, or natural organic matter refers to the large source of carbon-based compounds found within natural and engineered, terrestrial, and aquatic environments. It is matter composed of organic compounds that have come from the feces and remains of organisms such as plants and animals . [ 1 ]

  8. Organic compound - Wikipedia

    en.wikipedia.org/wiki/Organic_compound

    Nickel tetracarbonyl is typically classified as an organometallic compound as it satisfies the broad definition that organometallic chemistry covers all compounds that contain at least one carbon to metal covalent bond; it is unknown whether organometallic compounds form a subset of organic compounds. For example, the evidence of covalent Fe-C ...

  9. Persistent organic pollutant - Wikipedia

    en.wikipedia.org/wiki/Persistent_organic_pollutant

    The stability and lipophilicity of organic compounds often correlates with their halogen content, thus polyhalogenated organic compounds are of particular concern. [1] They exert their negative effects on the environment through two processes: long range transport, which allows them to travel far from their source, and bioaccumulation, which ...