EHS-120 Industrial Hygiene Sampling

5.1 General Guidance

5.1.1 Review qualitative assessments, existing industrial hygiene data and production documentation to help determine:

5.1.1.1 What will be sampled – identify the key contaminants that should be sampled. These may be active pharmaceutical ingredients, excipients or industrial chemicals. If you are handling chemicals subject to specific regulatory exposure limits then exposures need to be assessed in line with regulatory requirements.

5.1.1.2 Who will be sampled – collect samples on colleagues who are performing tasks. If more than one colleague is involved, sample at least two colleagues.

5.1.1.3 Where to sample – determine if general area samples will be collected in conjunction with personal samples. Obtain one sample near to the source (within 1m) and one sample outside the area. Take additional samples to evaluate performance of specific controls.

5.1.1.4 When to plan sampling – sampling should be planned to represent normal operating conditions during the highest dosage production for a given product. This will represent the worst-case scenario.  Use the qualitative assessment to identify steps of the production process or operation. Isolating steps will assist in determining where exposures are occurring and help focus control efforts.  Ensure that you refer to the production schedule to coordinate sampling with production activities.

5.1.1.5 How many samples should be collected – aim to collect at least three samples during each sampling event. If possible, conduct sampling events on three separate occasions to ensure that results are representative of typical conditions. Be aware of maximum sample times to ensure that sampling media is not overloaded and minimum sample times to ensure that enough contaminant is collected in the sample period. This information can be obtained by the Industrial Hygiene laboratory conducting the sample analysis.

5.2 Sampling Strategy

5.2.1 Personal Exposures

5.2.1.1 Full Shift – Sample operator(s) in breathing zone for three days on a full shift basis (minimum of 3 samples). This will provide information about of the magnitude of exposures for all the operations. The results should be compared to the 8 hr TWA for the chemical.

5.2.1.2 Task or Unit Operations – Sampling of tasks or unit operations is usually conducted in addition to full shift samples, as it represents a more detailed look at personal exposures.  Make use of existing full shift data where possible to conserve resources, that is, where few changes have occurred in the operation.

Sample operator(s) on three separate occasions during specific unit operations identified during the qualitative assessment.

If tasks are short duration (<20minutes), consider using one sample media / holder for all occasions combined; adding the sample periods together to give a total of 30 minutes exposure minimum.

Under normal circumstance sampling is conducted outside RPE (Respiratory Protective Equipments) worn, however sampling inside RPE may be conducted if actual colleague exposure to an air contaminant must be determined or a listed protection factor of a respirator is to be validated.

5.2.2 Area (Static) Samples

5.2.2.1 Take area samples at the same time as the full shift personal samples if pump resources allow. Fix the location of the sample within the processing area using a tripod assembly approximately 1m from equipment/operation at head height (1.5m from floor).  Sample concurrently outside the processing area at a fixed location.

5.2.3 Verification of Engineering Controls

5.2.3.1 Area sampling during specific tasks is used to assess performance of existing and new engineering controls. Where new equipment or controls are installed verification testing should be factored into the project installation timeline and a surrogate sampling material, lactose, used to determine engineering performance.

5.2.3.2 Where verification of existing engineering controls, upgrades to exiting equipment or where the opportunity of using lactose has been missed, sampling for active pharmaceutical ingredients may be used to assess engineering performance within a manufacturing schedule.

5.2.3.3 Personal Sampling

Sample operator(s) on six separate occasions during tasks identified.

5.2.3.4 Area Sampling

Take area samples for the duration of the task/operation to be assessed – see generic unit operations below for examples. Fix the location of the sample within the processing area using a tripod assembly approximately 1m from equipment/operation at head height (1.5m from floor).  Sample concurrently outside the processing area at a fixed location. Consider placing more than one area sampler around the potential source of dust.  It may be necessary to form a circle or semi circle depending on the shape of the equipment.

5.2.4 Generic Unit Operations

5.2.4.1 Manual operations controlled by ventilation e.g. weighing and dispensing, charging. Booths:  Collect four area samples per task simultaneously at the following locations:

30cm inside the safe zone (red line) at worker / equipment entrance.

30cm outside the safe zone at worker / equipment entrance.

Each side of the booth, 30cm from the wall at the boundary of the safe zone.

5.2.4.2 Material flow through transfer valves e.g. bin to bin processing (drying, blending, milling), bin feeding (tabletting, encapsulation).

Collect four area samples simultaneously around the transfer valve during material connection, material transfer and disconnection.  Sampling pumps should be located approximately 1m from the outer edge of valve.

5.2.4.3 Enclosed operations e.g. isolators, glove bags and totally enclosed systems e.g. alpha/beta ports inside isolators.

Collect four area samples simultaneously around the transfer valve during material introduction, manipulation, removal of waste bags. Sampling pumps should be located approximately 1m from the outer edge of isolator at head height of the operator, i.e. height depends whether the operator is seated or standing.

Samplers are located close to HEPA filter outlet and glove ports.  Actual sampling positions will vary between installations BUT will be fixed for a specific installation unless sampling indicates otherwise.