Influence of Good Working Practice on Exposure – Example Spray Application
Workshop: Occupational Safety and Health during the use of biocides – 3. – 4. April 2006 (BAuA, Dortmund, Germany)
Dr. Stephanie Melching-Kollmuss
Research project: „Workplace exposure from the use of biocidal
products – Part 1: Inhalation and dermal exposure data for the spray application of liquid biocidal products“
EU Biocides Directive 98/8/EC – requires exposure assessments
Focus: Biocidal products applied via spraying:
Compilation of biocidal products applied in Germany Simulation measurements in model rooms
Field measurements at selected workplaces in different industries Development of a suitable model - Spray Expo
Research project: „Workplace exposure from the use of biocidal
products – Part 1: Inhalation and dermal exposure data for the spray application of liquid biocidal products“
Approach - Occupational situation:
Identification of relevant workplace situations/relevant spraying devices Aerosol spraying in model room with tracer solutions - Defined conditions Determination of inhalation and potential dermal exposure –
Field measurements – comparable results?
Identification of parameters influencing and determining the extent of exposure
Research project: „Workplace exposure from the use of biocidal
products – Part 1: Inhalation and dermal exposure data for the spray application of liquid biocidal products“
Relevant working places, where biocides are applied by spraying or fogging:
-Disinfection/Crop spraying in hospitals, canteen kitchens, stables
applies for product type 2, 3, 4 – Disinfectants and general biocidal products -Protection of food- or feedstuff in transport or storage
applies for product types 14, 15, 16, 18, 20 – Preservatives -Wood and masonry preservatives
applies to product types 7, 8, 10, 21 – Pest control -Antifouling product application
applies to product type 21 – Other biocidal products
Determination of inhalative and potential dermal exposure of professional applicants
Simulation measurements in model rooms
Measurement of inhalation exposure - Personal Aerosol Monitor – Respicon Respirable, thoracic, inhalable fraction
3 Spray applicators:
Low pressure sprayer (2 bar) 250 ml/min
980 ml/min
droplets: 100 – 300 µm) High pressure sprayer (160 bar)
133 ml/min 200 ml/min
droplets: 30 – 50 µm) Fogging apparatus
very small droplets
Simulation measurements in model rooms
Model rooms – 5.7 m x 4.2 m x 2.5 m (appr. 60 m3), 1 window, 1 radiator; walls and ceiling coated with woodchip paper, painted with wall paint; synthetic carpet
Spraying situations:
Floor and lower part of the wall Ceiling and upper part of the wall
Wall (horizontal spraying) – airless spraying Total room (only fogging apparatus)
Application time:
6 – 26 minutes Sprayed solutions:
1% fluorescein-Sodium (aqueous)
7-diethylamino-4-methylcoumarin (organic)
as fluorescence tracers and surrogates for active ingredients
Simulation measurements in model rooms
Particle distribution of the used spraying devices
0 100 200 300 400 500 600
d5 d50 d90
Low pressure devices Particle
sizes µm
Fogging
0.0 50.0 100.0 150.0 200.0 250.0
spray 12 l/h lower part
spray 40 l/h lower part
spray 12 l/h upper part
spray 40 l/h Upper
part
airless horizontal 6
l/h
airless horizontal 9
l/h
fogging weak fogging strong Cinh (aqueous solution) (mg/h)
Cinh (organic solvent) (mg/h)
Inhaled doses – model experiments – personal sampling
Application technique Dose
mg/h
Simulation measurements in model rooms
Results of model measurements – Inhalation exposure
Inhaled doses: Fogging > airless spraying > spraying with low pressure Droplet spectrum (size distribution):
Fine Coarse
Height of release: Ceiling Floor
Solvent: Organic solvent Water (droplet diameter)
Simulation measurements in model rooms
Determination of Potential dermal exposure Pads on different body parts:
Head, Chest outer and inner, Back outer and inner, Upper arms, Forearms, Thighs, Shins; Hands (not in all cases)
Size of pads 100 cm2
Calculation of potential dermal exposure using factors:
80th percentiles of body surfaces1,2
1 OECD Guidance Document for the Conduct of Studies of Occupational Exposure to Pesticides During Agricultural Application, 1997
2 EPA-Factor´s Handbook, 1995, 1997
Potential dermal exposure – model experiments - Pads
0,0 100,0 200,0 300,0 400,0 500,0 600,0 700,0
spray 12 l/h lower part
spray ca. 40 l/h lower part
spray 12 l/h upper part
spray ca. 40 l/h upper part
airless horizontal 6 l/h
airless horizontal 9 l/h
fogging weak fogging strong
head a (mg/h) upper arms a (mg/
upper thighs a (mg head o (mg/h) upper arms o (mg/
upper thighs o (mg
Application technique Dose
mg/h head a (mg/h)
upper arms a (mg upper thighs a (m head o (mg/h) upper arms o (mg
upper thighs o m
2239
Overhead spraying
Simulation measurements in model rooms
Results of model measurements – Potential dermal exposure Potential dermal doses:
Spray low pressure (ceiling) > Fogging > airless spray > spray low pressure (floor)
Large differences: total dermal doses varied from 10 mg/h to 5000 mg/h
Direction of spraying: Ceiling Floor
Solvent: Organic solvent Water (higher vapour pressure of organics)
Field measurements
Workplace measurements
Trained – untrained operator Piece of metal (AF 1-3)
Antifouling
(water based, 2 indoor, 2 outdoor) Timber house (TH 1-4)
Wood protection
Water based products Duckhouse (DH 1-2)
Water based products, Aircondition Henhouse (HH 1-3)
Veterinary hygiene
Small nozzle diameter, fogging Living room (LR 1-2)
Private area and public hygiene
Futher disinfectors in room Brewery (BR 1-2)
2 microcapsulated products Bakery (BA 1-6)
Food and feed area disinfection
Remarks Workplace
Area of biocide application
Inhalation exposure at selected workplaces
114200
0 50 100 150 200 250 300
inhaled dose rate µg/h
BA1 BA2 BA3 (at part overhead spraying)
BA4 BA5 BR1
(conical nozzle)
BR2 BA6 LR1 (small nozzle diameter)
LR2 (fogging) workplace ID (characteristic feature)
Small distance to object Micro-
capsules
2 further disinfecting operators
Org.
solution
BA: Bakery BR: Brewery LR: Living room
Inhalation exposure at selected workplaces
0 50 100 150 200 250 300
inhaled dose rate mg/h
HH1 HH2 DH1 (7 bar)
DH2 (40 bar)
TH1 ( indoor,
org. a.s.
0.25%)
TH2 (indoor, inorg. a.s.
7.3 %)
AF1 (trained operator)
AF2 (untrained
operator)
AF3 (improper application) workplace ID (characteristic feature)
HH: Hen house DH: Duck house TH: Timber house AF: Antifouling
Aircondi- tioning
Field measurements – factors influencing exposure
Results of Workplace measurements – Inhalation exposure – Summary
Outdoor application Timber houses
Training/proper application Antifouling
Air-conditioning Hen houses
Inhaled doses decrease
Pressure during application Duck houses
Concentrated solutions Timber houses
Small nozzle diameter (fogging) Living room
Overhead spraying Bakery
Inhaled doses increase
Potential dermal exposure
34392 20798
0
2000 4000 6000 8000 10000
TH1 ( indoor,
org. a.s.
0.25%)
TH3 ( outdoor,
org. a.s.
0.25%)
TH4 (outdoor, inorg. a.s.
7.3 %)
AF1 (trained operator)
AF2 (untrained
operator)
AF3 (improper application) workplace ID (characteristic feature)
dermal dose rate mg/h
body head
upper arms thighs
TH: Timber house AF: Antifouling Not shown:
Dermal exposure was
reduced to 1-5%, if operator wore protective gloves.
Influence of Good Working Practice on Exposure
Inhalation and Potential Dermal Exposure during Antifouling treatment:
Trained operator (Professional) >>> Untrained operator >>> improper application (elevated operating pressure, fawning), hand protection
National Technical Rules for hazardous chemicals describe proper working conditions:
Airspray technique forbidden
Suitable spraying devices and spraying directions given Frequent information of operator
Inhalation Exposure during disinfecting treatment in air conditioned rooms:
Henhouse (air conditioning) >>> Duckhouse (no air-conditioning)
Inhalation Exposure in bakeries
Use of microcapsulated products reduce inhalation exposure
Dermal Exposure at model experiments (E) and at workplaces (WP)
BA4 LR1 AF1 AF2
LR2 Tracer concentration in model
experiments was 1%
Concentration of a.s. at workplaces was standardized to 1%
Summary
Relevant parameters influencing the extent of exposure are:
Inhalation:
Type of spraying (fogging >> airless >> low pressure) Droplet size (fine >> coarse)
Height of release (ceiling >> floor) Solvent (organic solvent >> water)
Working place environment (Airconditioning >> no air-conditioning)
Good working practice (trained operator >> untrained operator >> improper application)
Use of microcapsulated products Dermal:
Spraying direction (Overhead >> Floor Solvent (Water >> organic solvent)
Good working practice (trained operator >> untrained operator >> improper application, hand protection)
Research project: „Workplace exposure from the use of biocidal
products – Part 1: Inhalation and dermal exposure data for the spray application of liquid biocidal products“
Project was performed at Fraunhofer ITEM Hannover on behalf of BAuA (1998 – 2004) -Prof. Dr. W. Koch (ITEM)
-Dr. Berger-Preiß (ITEM) -Dr. Mangelsdorf (ITEM) -Dr. Boehncke (ITEM) -Dr. Könnecker (ITEM) -Dr. Holthenrich (BAuA) -Dr. Auffarth (BAuA)
