Test EHC L20, CO and NOx
CH 02/54
0152-16538
GRIPENHÄLSAN
GH 02/54
The Gripen Health 2001-12-06
The Gripen Health 2001-12-06
Jonas Thorin
8 Ögärdesvägen
SE-433 30 Purtille
Exposure to motor vehicle exhaust fumes when garaging the PBV 302 with or without a Lagnö
156 exhaust filter.
Assigned by Stig-Allan Johansson. C FmLog FÖrsE
Background
Personnel who work in the vehicle storage area are exposed to motor vehicle exhaust fumes in
connection with their work in the garage. With no mechanical ventilation in the motor vehicle storage
area, there is a risk of there being unacceptably high levels of exhaust fumes. In order to improve the
situation, an exhaust filter, which reduces air pollutants, is used.
Problems caused by exposure to exhaust fumes manifests itself in the form of symptoms such as
headaches and bouts of nausea. There might also be some anxiety about the possible long-term health
effects.
Purpose, Scope and Delimitation
The purpose of the measures published is to examine the present exposure levels in connection with
garaging the PBV 302 with and without an exhaust filter. It has been assessed that the measures
conducted deliver an accurate overview of the present conditions.
The measures involve drivers' exposure during the moving in and out of the premises of a total of ten
vehicles.
The exposure risk during garaging can vary depending on external conditions such as wind direction
and wind speed.
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Test EHC L20, CO and NOx
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The Gripen Health 2001-12-06
Mapping
Measures
During combustion, a large number of substances are formed in petrol and diesel engines. In practice,
it is unnecessary and difficult, if not impossible, to measure exposure levels to all existing substances.
The measures therefore include the two gases, carbon monoxide and nitrogen dioxide, which are
present in AFS 200:3, and are written regarding their hygienic threshold limits and measures to be
taken against air pollution by using exhaust fumes indicators.
Exposure to motor vehicle exhaust fumes when garaging the Lagnö 156 PBV 302.
The PBV 302 is powered by a 6-cylinder, 9.6-litre overcharged diesel direct injection engine.
Measuring Equipment
Hand-held measuring equipment from the Clinic of Occupational and Environmental Medicine in
Örebro is used in the measuring process.
1. Gas meter CO, YMK No 2074. Model: Drager PAC 3.
2. Gas meter NO2, YMK No 2075. Model: Drager PAC 3.
During the measuring process, the measuring equipment was placed near the respiration zone, at the
shirt collar level, and was set at the Open position. After the measures had been conducted, the results
were analysed by using Drager's Software Gas Vision.
Measuring Location and Conditions
The measurements were carried out on 26 November at two apparently equivalent Lagnö 156.1
garages, both in the same building, by driving five vehicles into the garage area outside and afterwards
driving the vehicles to another place in the same garage. A total of ten vehicles were involved. The
vehicles in the first garage were equipped with EHC L20 exhaust fume filters during the entire time
the vehicles were in use.
During the measurement process, the driver occupied the driver's seat in each respective car with the
exception of the time which he spent moving from one vehicle to another.
Weather: a weak easterly wind, strength about 3-4 m/s, rain. Temperature about +5°C.
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Test EHC L20, CO and NOx
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The Gripen Health 2001-12-06
Results
A summary of the measurement results
Time
1. Place / activity
2002-11- Lagnö. Moving
26 08:44- vehicles in and out
09:02
of 5 PBV 302
hours
Without a exhaust
fumes filter
Average carbon monoxide Average nitrogen
content (time-weighted
dioxide content (timeaverage, ppm CO)
weighted average, ppm
NO2)
Hygienic threshold limit
Hygienic threshold limit
value when the substance value when the
is present in exhaust
substance is present in
fumes: 20 ppm
exhaust fumes: 1 ppm
6 ppm
0.03 ppm
2 ppm
0.00 ppm
Exhaust fumes filter
2001-11- Lagn. Running-in
26 08:22- and out of five
08:40
PBV 302
hours
With an exhaust
filter
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Test EHC L20, CO and NOx
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The Gripen Health 2001-12-06
Carbon monoxide measurement results
Without a filter
2002-11-26 Lagnö, without a filter, carbon monoxide.
Average at 08:44 - 09:02 hours, 6 ppm
Chart 1
Note: The arrow shows the result for an engine which was difficult to start.
With an EHC L20 exhaust filter
2002-11-26 Lagnö, with a filter, carbon monoxide.
Average at 08:22 - 08:40 hours, 2 ppm
Chart 2
Exposure to motor vehicle exhaust fumes during the garaging of a Lagnö 156 PBV 302.
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Test EHC L20, CO and NOx
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The Gripen Health 2001-12-06
Nitrogen dioxide results
Without a filter
2002-11-26 Lagnö, without a filter, nitrogen dioxide/
Average at 08:44 - 09:02 hours, 0.03 ppm.
Chart 3
Note: The arrow shows the result for an engine which was difficult to start.
With an EHC L20 exhaust filter
2002-11-26 Lagnö, with a filter, nitrogen dioxide.
Average at 08:22 - 08:40 hours 0 ppm.
Chart 4
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Test EHC L20, CO and NOx
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The Gripen Health 2001-12-06
Discussion and Conclusion
* The use of an EHC L20 exhaust fumes filter reduces levels of carbon monoxide and the nitrogen
dioxide content in inhaled air.
When garaging the PBV 302 without an exhaust fumes filter, while driving around the instructor is
exposed to a fluctuating concentration with short peaks:
- about 10 to a maximum of about 30 ppm carbon monoxide (see Chart 1). Average value 6 ppm,
- about 0.3 to a maximum of about 0.8 ppm nitrogen dioxide (see Chart 3). Average value 0.03 ppm
When garaging a PBV 302 with an EHC L20 exhaust fumes filter, the instructor was exposed to a
fluctuating exhaust fumes content with short peaks:
- about 5 ppm to a maximum of about 15 ppm carbon monoxide (see Chart 2). Average value 0.2
ppm,
The nitrogen dioxide content was below the measuring instrument's lower detection limit (see Chart
4). Average detection limit.
* Vehicles which are difficult to start increase the air pollutant content considerably. The effects of a
vehicle which is difficult to start (and which is without a filter) at about 08.55 hours can be seen in the
measurement curves (Charts 1 and 3) in the "third peak", marked by an arrow.
One of the vehicles which did not have an exhaust fumes filter and which was difficult to start
increased the average value considerably. The average levels of carbon monoxide should therefore
have been below 6 ppm if all vehicles had started up straight away.
* The hygienic limits for carbon monoxide and nitrogen dioxide in exhaust fumes were not exceeded
during the measurement process (for limit values, see the explanations in Enclosure 3).
Exposure
The main tasks consist of garaging, moving vehicles around, plus renovation and servicing work.
Garaging is estimated to total about 30 hours of work per week.
Vehicles
At present the following vehicles are managed:
-100 pcs PBV 302 (diesel)
- 20 pcs BV206
-300 pcs TGB 30 (diesel)
-200-300 pcs TGB 11,12, 14 and 20 (petrol)
Within the near future the number of PBV 302 vehicles might increase from about 100 pcs to 300-400
pcs.
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Garage
The garage does not possess general mechanical ventilation, nor is it fitted with comfort ventilation
such as an exhaust fumes extractor. In some of the garages used, the prerequisites for acceptable air
quality levels are improved as they can be opened up at both ends, which provides a better ventilation.
Inside the garage, several cars often stand in a queue. When one vehicle in this queue has to be run
out, some vehicles which are ahead of it must also be driven out, which increases the exposure levels
to exhaust fumes.
Other
There are two indicator substances for the specified exhaust fumes in the list of limit values in AFS
2000:3;
Substance
Limit level value ppm
Carbon monoxide
20
Nitrogen dioxide
1
The following is evident from the directions:
"The specific threshold limit values for nitrogen dioxide and carbon monoxide refer to the total effect
of the substances which are present in exhaust fumes including cancer-inducing substances. These
substances are used as indicator substances. Exposure levels have to be acceptable with regard to
both values. In case of exposure to exhaust fumes from petrol and LPG engines, the carbon monoxide
value might be decisive while in the case of diesel exhaust fumes the nitrogen dioxide value receives
the same dimensioning. On the other hand, we should be careful not to assess the additive effect
between carbon monoxide and nitrogen dioxide."
As the PBV 302 runs on diesel, nitrogen dioxide might be considered as a "dimensioning" indicator
substance.
General Information on Problems Related to Exhaust Fumes
The smell of exhaust fumes has a great importance in regard to the degree of discomfort experienced.
Petrol and diesel exhaust fumes have different structures. Exhaust fumes from petrol engines have a
relatively high carbon monoxide content. Exhaust fumes from diesel engines have a relatively high
content of nitrogen oxides, aldehydes and particles.
The main risk factors in exhaust fumes are nitrogen oxides, carbon monoxide, vapours from organic
solutions such as benzene and toluole, aldehydes, and heavier organic molecules such as polyaromatic
hydrocarbons with derivates. Nitrogen oxides and aldehydes are probably the source of the effects
seen on lungs and mucous membranes. Carbon monoxide and organic solutions can lie behind
symptoms related to the nervous system. Organic solutions and polyaromatic hydrocarbons with
derivates are probably the reason behind germ plasma changes.
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Test EHC L20, CO and NOx
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Nitrogen dioxide, NO2
Nitrogen dioxide can lead to acute lung disorders. Trials with people have shown that:
At a level of 0.02-0.05 ppm: there is an increased presence of respiratory-related problems and
respiratory diseases. This especially applies to children (thanks to long-term exposure)
Hours of exposure)..
At a level of 0.1-0.3 ppm: there are increased levels of sensitivity and resistance in the airways of
people with asthma (0.5-2 hours of exposure).
At a level of 1-3 ppm: there is increased sensitivity (relativity) and resistance in the airways of people
who do not have asthma (0.5-2 hours of exposure).
Source: Hansson & Hellsun. Arbetsmiljö från A till O (Working environment from A to O), Fourth Edition.
Carbon monoxide, CO
Carbon monoxide affects both physical and mental performance.
With a concentration of 30-50 ppm in the air being inhaled over the course of a whole working day,
we can expect about 5% of the blood’s haemoglobin to be blocked by carbon monoxide. The result is
a smaller decrease in performance levels. People with heart disease might experience problems.
There is a risk of intoxication with lower contents such as 200-500 ppm.
In the case of contents of a level which cause more than 50% of the blood’s haemoglobin to stop
transporting oxygen, the fumes cause death. In the case of exposure to a 3.5 volume per cent (35000
ppm) for less than ten minutes, the expected death rate is 50%.
Rules
Exhaust fumes extractor
According to AFS 1998:8 Work in the motor vehicle industry 4§ applies: "If a combustion engine is
run in one place for a period of time longer than that which is necessary for the vehicle to be moved in
and out of the premises, a separate exhaust fumes extractor shall be used... The exhaust fumes
extractor shall be sized according to the largest volume of exhaust fumes expected to be discharged at
this particular location".
Important AFS
AFS 1998:4 Use of working equipment
AFS 1998:8 Work in the motor vehicle industry
AFS 2000:3 regarding hygienic threshold limit values and measures to be taken against air pollution.
AFS 2000:42 Workplace design
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