Occupational Safety & Health Calculators

Engineer-grade EHS calculators: NIOSH lifting index, WBGT heat stress, arc flash boundary, noise exposure, fall clearance, and more.

Available Tools

Safety and Industrial Hygiene Math, Consolidated

This domain collects the recurring calculations EHS managers, industrial hygienists, plant safety officers, and construction safety supervisors run on a weekly or daily basis. Convert a measured sound pressure record into L_Ex,8h and compare it against the OSHA 29 CFR 1910.95 action level. Derive WBGT from dry-bulb, natural wet-bulb, and globe temperatures and select ACGIH TLV work-rest allocations before authorizing hot work or outdoor labor. Compute arc flash boundary and approach distances as a first-pass screen. Score a manual handling task with the NIOSH Revised Lifting Equation and produce a defensible Lifting Index for JSA documentation. Check a portable ladder against the 4:1 base-to-height rule. Each tool is deterministic, shows intermediate multipliers, and cites the underlying standard clause so the result is traceable back to the regulation or guideline that governs it.

Who These Tools Are Built For

The primary users are site-level safety managers preparing job hazard analyses, industrial hygienists running exposure screens, construction safety officers verifying fall-arrest clearance or ladder setup, and small-employer owners who must produce a written program without a consulting retainer. The calculators are also used by ergonomists scoring lifting tasks, facilities engineers sizing mechanical ventilation for confined-space entry, and HSE trainees learning how TLV, PEL, REL, and STEL values translate into field numbers. They are not a substitute for an IEEE 1584-level arc flash incident energy analysis, a formal industrial hygiene sampling campaign with statistical exposure assessment, Safety Data Sheet authoring, or regulatory filings such as OSHA 300 logs. For any of those deliverables, engage a licensed professional engineer, a certified industrial hygienist, or competent legal counsel and treat the calculator output as supporting evidence only.

Standards and Regulatory Basis

The equations implemented here trace to well-established consensus and regulatory sources. OSHA 29 CFR 1910 subparts govern general industry: 1910.95 for occupational noise exposure and the 5 dB exchange rate, 1910.134 for respiratory protection and assigned protection factors, 1910.146 for permit-required confined spaces, and 1910.1200 hazard communication. Construction work references 29 CFR 1926, including subparts M (fall protection) and X (ladders). Ergonomic scoring uses the NIOSH Revised Lifting Equation (DHHS Publication 94-110) and ISO 11228 parts 1-3. Heat stress follows ACGIH TLVs and ISO 7243 WBGT methodology. Illuminance targets reference IES RP-7 industrial lighting. Arc flash boundary screening acknowledges IEEE 1584 as the authoritative method while using the simplified approximations suitable for pre-study estimation. Fall-arrest clearance follows ANSI/ASSP Z359 and OSHA 1926.502. Functional safety context draws on IEC 61508/61511 where process applications demand SIL assessment.

What This Site Does Not Do

These calculators are purpose-built for quick, reproducible engineering arithmetic. They do not constitute a formal arc flash study: producing labels that comply with NFPA 70E requires a site-specific short-circuit and coordination study, protective device time-current analysis, and professional engineer sign-off, none of which a generic calculator can substitute for. The tools do not perform regulatory compliance audits; they compute values, not legal conclusions about OSHA citations, state-plan equivalents, or EU directive conformity. They do not support incident investigation or root cause analysis workflows. They do not conduct a full industrial hygiene exposure assessment with AIHA-style statistical analysis of sampling results, confidence intervals, or similar exposure group banding. They do not author Safety Data Sheets, GHS classifications, transport documents, or chemical inventory reports. For audits, investigations, SDS authoring, or any output carrying legal weight, engage qualified professionals and use these calculators only as preparatory or cross-check aids.