TLV Basis
Tools and Instruments
Axiomatic Hygiene
Seeing is Believing
IEJ Every Day
Not Roses By Any Name
100
This 10-syllable TLV basis refers to a condition of functional hypoxia caused by carbon monoxide—either directly inhaled or produced through metabolism of dichloromethane (methylene chloride).
Carboxyhemoglobinemia (COHb-emia).
100
The Davy Lamp, pictured here, was one of the first instruments used to detect this type of gas or atmosphere.
Flammable
100
This is what the dose makes, according to Paracelsus.
The poison.
100
As shown in this video, this type of light reveals the vaporization of mercury at room temperature, highlighting one of the reasons that the condensate is so prolific.
Ultraviolet (UV)
100
Improving Exposure Judgements (IEJ) is a long-term initiative to elevate the risk-assessment abilities of OEHS professionals, launched jointly by AIHA and this 5-letter organization.
American Conference of Governmental Industrial Hygienists (ACGIH).
100
Giggles aside, this gas is no laughing matter.
Nitrous oxide (or dinitrogen monoxide).
200
This group of TLVs is split into two TLV basis components: one for medical device wearers, and one for those without.
Electromagnetic Fields (EMF) or something similar.
200
Named after this author who published the schematic seen here in the Journal of Bacteriology in 1958, this device was designed to sample for viable airborne bacteria or fungi using a cascade impactor.
Andersen
200
This type of control is known as "the last line of defense."
Personal Protective Equipment (PPE).
200
As shown in this video, this substance forms an underwater river in Mexico due to it's high density.
Hydrogen sulfide.
200
Statistician George E. P. Box observed that all models are wrong, but some are this.
Useful.
200
Jack be nimble, jack be quick - but only quick enough to earn this liquid silver.
Mercury.
300
DOUBLE TROUBLE
The TLV for Heat Stress and Strain is based on the ability of most healthy, hydrated, acclimatized workers to achieve and maintain this status.
Thermal equilibrium.
300
The two instruments pictured here are examples of this type of infrared spectrometry that identifies molecules based on their characteristic absorption spectrum.
Fourier Transform Infrared (FTIR).
300
This biological agent, belonging to a distinct kingdom of life, is considered omnipresent in outdoor air and in most indoor environments.
Mold
(also acceptable is yeast, or fungal spores)
300
As shown in this video, Naica Cave is filled with enormous selenite crystals and this physical hazard, which is especially dangerous when combined with high humidity.
Heat (or thermal stress)
300
Improving Exposure Judgements (IEJ) philosophy includes expressing exposure conclusions accompanied by a numerical value of this concept, often evaluated against benchmarks such as 70 or 95 percent.
Confidence (or statistical confidence).
300
Please don't offer bitter criticism to this acid also known as "oil of vitriol".
Sulfuric acid. (Sulfuric is fine)
400
Also known as cyclohexatriene, this compound is well known as an Group A1 - Confirmed Human Carcinogen and has a TLV basis that most notably identifies leukemia, but also includes myelodysplastic syndrome (MDS), hematologic effects, and chromosomal damage.
Benzene.
400
Instruments that use this effect generate voltage when deformed, as seen in this image.
By Tizeff - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2961245
Piezoelectric
400
This risk management philosophy emphasizes continual exposure reduction using feasible controls, rather than simply meeting numerical exposure limits.
As Low as Reasonably Achievable (ALARA).
Also acceptable: ALARP.
400
As seen in this video, this effect - a type of scattering - is responsible for the visual effect of floating particles suspended in the air.
Tyndall
400
DOUBLE TROUBLE
This field of statistics named after an English statistician is based on an interpretation of conditional probability of an event based on both data and prior information about conditions.
Bayesian (Bayesian statistics).
400
Named colloquially for the inventor of geodesic domes, this 60-carbon fullerene has a bouncy name that relates to it's spherical structure.
Buckyball
Also, Buckminsterfullerene if needed.
500
ACGIH recommendations for particles not otherwise specified (PNOS) apply to particles that do not have an applicable TLV, have low toxicity, and are insoluble or poorly soluble in water or, preferably, this aqueous fluid if data is available.
Lung fluid.
500
The apparatus pictured here is designed for simultaneously collecting this combination of phases.
Inhalable Fraction and Vapor (IFV)
500
Because all measurements are subject to error, there is always a fundamentally unknowable difference between measured exposure and this conceptual degree of exposure.
True exposure.
500
As seen in this video, this type of radiation only occurs when charged particles pass through an optically transparent medium at speeds greater than that medium's speed of light.
Cherenkov
500
This is the total combined cost of AIHA's IEJ online course, plus the fee required to take the test to become an Registered Specialist in Exposure Decision Analysis.
$0. FREE. Amazing but true.
500
The IUPAC would call this compound 3-Oxoolean-18-en-28-oic acid, a natural triterpene first isolated from the Mora excelsa tree, with a synonym that questions its intelligence.
Moronic acid.
If they come up with Ambrionic acid, that's correct but they should be booed.