ADE/PDE, OEL & Cleaning Validation
Occupational exposure limit (OEL) determination and exposure assessment
An occupational exposure limit (OEL) tells you how much airborne substance a worker can be exposed to over a shift without expected harm. On its own it is a number; compared with how people actually handle the material, it becomes a basis for containment and protection decisions. We provide both.
- Guideline basis Toxicological OEL derivation consistent with the EMA HBEL approach and ISPE Risk-MaPP
- Typical inputs Toxicology data, process descriptions, available air-monitoring results
- You receive OEL monograph and an exposure assessment with recommendations
Overview
About OEL Determination & Exposure Assessment
OELs are usually expressed as an 8-hour time-weighted average concentration in µg/m³. They are derived from the same toxicological evaluation as a PDE, adjusted for inhalation exposure, breathing volume over a shift and the relevant body weight. Short-term limits may be added for acutely acting substances.
The exposure assessment then compares the OEL with what is expected or measured during real tasks — dispensing, charging, milling, sampling or cleaning. The outcome is a clear view of where existing controls are adequate and where they should be improved.
Use cases
When this service helps
Handling a new or potent API
Set a limit before scale-up so containment can be designed in rather than added later.
Interpreting air-monitoring results
Understand whether measured concentrations represent an acceptable risk.
Selecting containment and PPE
Choose between open handling, ventilated enclosures, isolators or respiratory protection.
Customer or auditor questions
Provide documented limits when a partner or auditor requests them.
Scope
What the service covers
- Toxicological derivation of an 8-hour OEL (and short-term limit where justified)
- Assignment of an occupational exposure band to support control selection
- Review of process steps, quantities handled and frequency of tasks
- Interpretation of air-monitoring and surface-wipe data supplied by your industrial-hygiene provider
- Qualitative or modelled exposure estimates where no measurements exist
- Recommendations on engineering controls, procedures and personal protective equipment
Who does what
Air sampling and laboratory analysis are carried out by your industrial-hygiene provider. Globaxa derives the limit, interprets the results and documents the risk assessment.
How does an OEL differ from a PDE?
Both start from the same point of departure. The OEL is expressed as an airborne concentration and accounts for the volume of air breathed during a shift (commonly 10 m³), worker body weight and absorption by inhalation.
Methodology
How we work
A defined sequence, agreed with you at the start, so you always know what happens next and what we need from you.
- Derive the OELToxicological review, point of departure and adjustment factors adapted for inhalation exposure.
- Understand the tasksWe review how the substance is handled, in what quantities and for how long.
- Compare exposure with the limitMeasured or estimated exposure is compared with the OEL for each task.
- Recommend controlsWhere the margin is small, we recommend proportionate engineering and procedural measures.
Deliverables
What you receive
OEL monograph
Derivation of the occupational limit with data, factors and rationale.
Exposure assessment
Task-by-task comparison of expected or measured exposure with the OEL.
Control recommendations
Prioritised actions for containment, monitoring and protective equipment.
Technical basis
Guidelines we work to
- EMA HBEL guidelineProvides the toxicological framework used to derive health-based limits.
- ISPE Risk-MaPPLinks ADE and OEL derivation to risk-based control of cross-contamination and operator exposure.
- Occupational hygiene practiceComparison of exposure with limits follows established industrial-hygiene principles; national occupational-safety rules also apply.
What we need from you
- Substance identity and any available toxicology or PDE/ADE reports
- Process descriptions, quantities handled and task frequency
- Existing containment equipment and PPE in use
- Air-monitoring or wipe-sampling results, if available
Please share confidential information only after an NDA is in place — we are happy to sign one first.
Market and jurisdiction considerations
Occupational limits for APIs are generally company-derived rather than set by regulators, so a well-documented monograph is important. Local occupational-health legislation in each country of operation also applies and may set additional requirements.
FAQs
OEL Determination & Exposure Assessment: frequently asked questions
Do you carry out air sampling?
No. We work with results from your industrial-hygiene provider or recommend what sampling is needed.
Can an OEL be set without much data?
A provisional band can be assigned using potency and hazard information, then refined into a numerical OEL as data become available.
Is an OEL the same as a regulatory exposure limit?
Not usually. For most APIs there is no statutory limit; companies derive their own OELs to protect workers, while general chemical-safety laws still apply.
Talk to us about OEL Determination & Exposure Assessment
Share your product, target market and timeline. We will review your requirement and propose a defined scope.
- OfficeFlat no 8-9-3/23/1, Subhash Chandra Bose Colony, Dathunagar, Kanchanbagh, Hyderabad, Telangana 500058, India
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+91 99894 74590 - Emailbd@globaxa.in
- Office hoursMonday to Friday, 10:00–19:00 IST