In the United States the Controlled Substance Act (CSA) is the federal drug policy under which the manufacture, importation, possession, use, and distribution of certain substances are regulated.
Photodynamism, conversion of certain substances in the skin of animals into other substances by the action of light.
I think he was smiling because of certain substances, but hey, you never know.
Namely, the monitoring of certain substances in CSF system will reveal nothing about the "circulation" of CSF, but only about the distribution of that substance within the CSF.
Blood is drawn to measure the levels of certain substances in the mother's blood.
But it is of particular concern for the makers of solar panels, which were not previously covered by the law, known as the directive on the restriction of the use of certain hazardous substances in electrical and electronic equipment.
last summer, but it seems likely to remain stalled there because of the Administration's yielding to pressure from the American military for the continued use of certain toxic substances.
Restriction of the use of certain Hazardous Substances in electrical and electronic equipment.
Restricted chemicals are listed in Annex XVII of the REACH regulation (Annex XVII, Restrictions on the manufacture, placing on the market and use of certain dangerous substances, preparations and articles).
The emergence of new regulations for the disposal of electrical and electronic equipment, directives on the use of certain hazardous substances, and the Kyoto Protocol are changing industries approach to product design and manufacturing.
