Common use of SCOPE AND LIMITATIONS Clause in Contracts

SCOPE AND LIMITATIONS. (i) Phase 2 testing separates test chemicals into three convenient categories: ‘‘Photolabile’’, ‘‘photoinert’’, and those chemicals having sunlight half-lives in round tubes in the range of 1 hour to 50 days. Chemicals in the first two cat- egories fall outside the practical limits of the test, and cannot be used in Phase 3. All other chemicals are suit- able for Phase 3 testing. (ii) The test procedure is simple and inexpensive, but does require that the chemical dissolve in water at sufficient concentrations to be measured by some analytical technique but not have ap- preciable absorbance in the range 290 to 825 nm. Phase 2 tests should be done during a clear-sky period to obtain the best results. Testing will be less accu- rate for chemicals with half-lives of less than 1 day because dramatic fluc- tuations in sunlight intensity can arise from transient weather conditions and the difficulty of assigning equivalent reaction times. Normal diurnal vari- ations also affect the photolysis rate constant. Phase 3 tests should be start- ed as soon as possible after the Phase 2 tests to ensure that the (kp)SHW esti- mate remains valid.

SCOPE AND LIMITATIONS. (i) Phase 2 testing separates test chemicals into three convenient categories: ‘‘PhotolabilePhoto- labile’’, ‘‘photoinert’’, and those chemicals chemi- cals having sunlight half-lives in round tubes in the range of 1 hour to 50 days. Chemicals in the first two cat- egories categories fall outside the practical limits of the test, and cannot be used in Phase 3. All other chemicals are suit- able suitable for Phase 3 testing. (ii) The test procedure is simple and inexpensive, but does require that the chemical dissolve in water at sufficient concentrations to be measured by some analytical technique but not have ap- preciable absorbance in the range 290 to 825 nm. Phase 2 tests should be done during a clear-sky period to obtain the best results. Testing will be less accu- rate for chemicals with half-lives of less than 1 day because dramatic fluc- tuations in sunlight intensity can arise from transient weather conditions and the difficulty of assigning equivalent reaction times. Normal diurnal vari- ations also affect the photolysis rate constant. Phase 3 tests should be start- ed as soon as possible after the Phase 2 tests to ensure that the (kp)SHW esti- mate remains valid.