Precision tools for occupational health and safety.

Levels below 80 dB(A) accumulate no dose. The exchange rate, not the measurement, is what separates these three.

Table 3 is a screening tool and is more protective than the analytical TLV, so the two can disagree. Both are shown. The limit governing this worker is the TLV.

A(8) = √( Σ aₕᵥ² · T / 8 ), per ISO 5349-1. Vibration total values are the tool’s input, not single-axis readings.

Point-source geometry with exponential attenuation and a geometric-progression build-up factor (ANSI/ANS-6.4.3, air-kerma response), applied per gamma line. Build-up assumes an infinite scattering medium, which is slightly conservative for a finite shield. Skyshine and source self-absorption are not modelled.

Between 400 MHz and 2 GHz the reference level is proportional to frequency (f/40 occupational, f/200 public), so it is read at the measured frequency, not off a plateau. A reference level is a measurable proxy for the basic restriction: exceeding it is not automatically a breach, it means the basic restriction has to be assessed directly.

NIOSH 1994. The equation assumes two-handed, smooth lifting with good footing; it does not cover carrying, pushing or one-handed work.

The table is the answer. Picking one limit for a workplace is a decision about jurisdiction and duty of care, and the tool does not make it for you.

An extended shift shortens recovery as well as lengthening exposure. Brief & Scala reduces the limit for both, so the exposure is averaged over the actual 12 h rather than normalised to 8 h; normalising as well would count the shift length twice and overstate the exceedance. The tool also offers the OSHA, Quebec/IRSST and pharmacokinetic models, which do not agree.

The LEL falls as temperature rises, so a reading that is safe on the bench is not necessarily safe in the vessel. The correction is applied and shown.

A correction factor belongs to an instrument AND a lamp energy. Applying one manufacturer’s factor to another’s instrument, or a 10.6 eV factor to a 9.8 eV lamp, is a common and invisible error.

Banding is a decision procedure, not a measurement. It says what standard of control to apply when there is no exposure data; it does not tell you the exposure.

A result of 84 % of the OEL is not a pass if the interval reaches past it. Workplace variability usually dominates the budget, and it is the component most often left out.

The action level shown is half the TLV — a general hygiene practice, not an ACGIH-published value, and the tool says so. Results obtained by a method other than BS EN 14031 are not directly comparable to the TLV.

There is no single risk score. An untouched questionnaire produces no deficiencies at all, which would read as low risk, so the tool reports completeness separately from findings.

Risk group is a property of the organism; containment level is a property of the work. The level shown is the starting point the risk group indicates, and procedures that aerosolise or concentrate an agent may require a higher one.

There is no fatigue score. No regulator publishes a weighting or a band for a roster, so the tool reports a finding per clause and counts what could not be tested separately from what passed.

Ten samples is a small set. The gap between the point estimate and its upper confidence limit is the honest measure of how little that sample size settles.