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In analytical chemistry, the detection limit, lower limit of detection, also termed LOD for limit of detection or analytical sensitivity (not to be confused with statistical sensitivity), is the lowest quantity of a substance that can be distinguished from the absence of that substance (a blank value) with a stated confidence level (generally 99%).
An occupational exposure limit is an upper limit on the acceptable concentration of a hazardous substance in workplace air for a particular material or class of materials. It is typically set by competent national authorities and enforced by legislation to protect occupational safety and health.
The permissible exposure limit (PEL or OSHA PEL) is a legal limit in the United States for exposure of an employee to a chemical substance or physical agent such as high level noise. Permissible exposure limits were established by the Occupational Safety and Health Administration (OSHA).
Threshold limit value − time-weighted average (TLV-TWA): The average exposure on the basis of a 8 hours per day, 40 hours per week work schedule. Threshold limit value − short-term exposure limit (TLV-STEL): A 15-minute TWA exposure that should not be exceeded at any time during a workday, even if the 8-hour TWA is within the TLV-TWA.
A typical detection limit for radioactive caesium is about 40 Bq. The Annual Limit on Intake (i.e., the amount that would give a person a dose equal to the worker limit that is 20 mSv) is about 2,000,000 Bq. The amount of naturally occurring radioactive potassium present in all humans is also easily detectable. Risk of death by potassium ...
Typical setups allow for detection limits corresponding to optical depths of 0.0001 along lightpaths of up to typically 15 km and thus allow for the detection also of weak absorbers, such as water vapour, nitrous acid, formaldehyde, tetraoxygen, iodine oxide, bromine oxide and chlorine oxide.
Hazard analysis critical control points, or HACCP (/ ˈ h æ s ʌ p / [1]), is a systematic preventive approach to food safety from biological, chemical, and physical hazards in production processes that can cause the finished product to be unsafe and designs measures to reduce these risks to a safe level.
Considering detection limit, both TCD and FID reach low concentration levels (inferior to ppm or ppb). [2] Both of them require pressurized carrier gas (Typically: H 2 for FID, He for TCD) but due to the risk associated with storing H 2 (high flammability, see Hydrogen safety), TCD with He should be considered in locations where safety is crucial.