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>):,'iv,NY TECHNICAL REPORT
Addendum Report #3: Additional Studies on VCM Adsorption
. OC A riON
M. M. O'Mara/G. A. Lees
I Avon Lake Technical Center
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! i f May 25, 1974 typed: May 28, 1974
A number of VCM exposures involving new adsorbents, commercial adsorbants at low VCM exposures, and a variety of exposure conditions have been carried out. During the course of this continuing study we have replaced the Century OVA with a Bendix Hydrocarbon Analyzer, in summary we have found:
(1) The Bendix analyzer far outperforms the Century analyzer in terms of stability, background and accuracy,
(2) carbon remains to be the best adsorbent for VCM,
the life-time of the Welsh cartridge in terms of 1 ppm breakthrough ranges between 30 minutes and 90 minutes,
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<4) the Welsh canister outperforms anything evaluated to date.
X03S9W Z
J. L. Nelson E. W. Harrington G. D. Schaaf B. A. DiLiddo E. G. Schwaegerle W- Wilcox
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B. M. G. Zwicker H. Waltemate E. B. Katzenmeyer, F. E. Krause R. M. Kreager J. Fausch P. Zakriski
UP PILE * C Q NO.
A. L. Schultz R. W. Strassburg M. N. Johnson L. B. Crider E. A. Collins L. A. Chandler
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R. J. Meyer C, Flynn
D. L. Kent Plant Managers
Plant Safety Engineers
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Introduction
Our last report (B.F.G. Technical Report, March 8, 1974) on the subject of VCM adsorption covered evaliB tiors of new adsorbants and larger carbon canisters and cartridges. Since thuu .enort we have continued our studies in this area and have also prepared VCM standards in support of other investi gations (gas chromatographic, chemical desorption, x-ray studies). This current report is a summary of this work. A summary of all experiments is provided in Table 1. No detail is given for the Analytical Gas Standards (A.G.S.) prepared for other studies; a permanent record of this work will be re tained.
During the course of this work we replaced the Century OVA with a Bendix Total Hydrocarbon Analyzer. One of the advantages with the Bendix instrument is the ability to determine VCM breakthrough times below T5. An attempt was made to do this with the Century OVA at T 5 (see #33, 34) but there is considerable error in the values. The main reason is due to the inherent 5-10 ppm background in the Century analyzer. This background can be zero suppressed with the Bendix instrument. We have also found that the baseline is much steadier with the Bendix instrument. Baseline drift is probably the greatest source of error with the Century OVA analyzer, especially in the 0-5 ppm region. The agreement between the two methods considering the above limitations with the Century is not that bad. Testing the Welsh cartridge (7500-1) at 15 liters/min. and 10 ppm of VCM we obtained the following breakthrough times (T 5)** for the two analyzers: T * *= 162 (Century) and T^ = 120 (Bendix) (see Experiments #33 and #63). Previously we had determined a 12% deviation in determining T5 with the Century analyzer.
In Table I, we have analyzed the Welsh 7500-1 cartridge at 30 1/min. and 10 ppm two times (#64 and #71) with the Bendix analyzer. The average Tq is 50 i 4 minutes which represents an 8% deviation- In our next report we will broaden the data base on this deviation analysis but reproducibility seems better with the Bendix instrument.
Effect of Rate on Breakthrough Time
Comparing experiments #63 and #64 a significant decrease in (initial breakthrough) takes place when the rate is increased from 15 1/min. to 30 1/min. A number of people have requested that more experiments be carried out at the 15 1/min. rate rather than the 30 1/min. rate. While the informatj^xi obtained at 15 1/min. is of interest, it should be remembered that in our approach we correlate to the OSHA standard when we test at 30 1/min. not at 15 1/min. Since final acceptance of any device is based on the OSHA standard, most of our testing should be in the 30 1/min. range (or whatever rate best correlates to the standard).
T^ Values
Our initial data involving the Welsh cartridge at 10-20 ppm (30 1/min.) indicates that Tj is reached between 1 and l hours. Although we have not yet
* T ^ is defined as the time to .5 ppm VCM/
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Page 2 May 28, 1974
determined at 50 ppm, previous vo- with the Century analyzer at 50 ppm indicates a Tj -- 41. We believe thio , h! ue is high, again due to the inherent problems with the Century analyzer at these low levels. Never theless in terms of the problem, the values (T^) indicate the approximate life-time of the Welsh cartridge. If the concern is worker exposure to 1 ppm of VCM, the Welsh cartridges exhibit a life of to 1^ hours depending on the concentration of VCM in the atmosphere.
Welsh Canisters
In our last report we showed the significant increase in protection offered by the Welsh canister (7800-1M). At 30 1/min. and 100 ppm, Tj was reached after 11 hours. Recent studies with this canister (Experiment #70) indicate that initial breakthrough, Tq, at 10 ppm and 30 1/min is almost 17 hours and Tj is not reached until ~20 hours. To date we have seen nothing that approaches the performance of the Welsh canister.
Other Adsorbants
A number of other adsorbants involving a number of principles of chemistry were tried. Nothing, so far evaluated, approached the effective ness of carbon in scavenging VCM. In our last report we found that the coconut charcoal was not as effective as the petro-charcoal. Since that report. Harvard has also tested the coconut charcoal in their apparatus and have arrived at the same conclusion. Thus at this time, coconut charcoal offers no real advantage over the more abundant petroleum based charcoal.
Future Studies
We will continue our studies along the following lines:
(1) datermine reproducibility (Tq, T y T^) at the low
(5*20 ppm) exposure concentration,
(2) follow the Harvard work now in progress in which engineering redesign experiments with the entire masks are underway,
(3) continue to evaluate new adsorbants, and
(4) evaluate the standard cartridges and canisters at low levels of VCM (1-5 ppm)
ch Attachment
M. M. 0'Mara
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Table 1
Experiment No.
31, 32
Summery of VCM Adsorption Data Obtained with the VCM Flow Chamber
Experiment InyolvinR
Flow Rate 1/min.
VCM Concentration DDO
'T. T5 (minutes)
A.G.S.
33 34 35 - 39 40 41 42 43 - 46
47 48 - 53 54 55 56 57 - 61 62
Welsh 7500-1 Welsh 7500-1L A.G.S. MSA Cartridge 44135 Willson R-13 Willson R-21 calcium carbonate absorbant repeat of #42 (R-21) A.G.S. MSA Cartridge 459315 MSA Cartridge 459315 Willson R-25 Ti0z, Lead Acetate absorbents Welsh 7500-1
63 Welsh 7500-1
64 Welsh 7500-1 65 Welsh 7500-1
66 67 68 69
Various carbon filters containing mixtures of carbon and other adsorbants; #67 is the control containing
* only carbon.
70 Welsh canister, 7800-1M
15 15
30 30 30 30 30
30 30 30 30 15
15
30 30
30 30 30 30 30
71 Welsh cartridge 75001 (repeat of #64)
30
10 T - 162; Tj = 278 10 T 5 - 291
100 13.0 100 0.0 100 57.0 100 all 0.0 100 46.5
50 32.0 100 25.0 100 11.0 100 All 0.0
20 data in error; will be repeated
10 T0 - 98, T , = 120; Tj - 148
10 T0 - 54, Tx - 92 20 T0 - 35, Tx = 57;
T5 - 77 100 13.0 100 32.0 100 12.0 100 0.0
10 TQ - 1010, Tl = 1220 t" - 1335
10 T0 - 46, Ti - 81
vi-'Tj Is the time (In minutes) In which the concentration of VCM downstream from the cartridge becomes S ppm.
(2)Analytical Gas Standard.
(5) Runs 31 to 61 were made with the Century 0.V.A.
(5)0.0 means Imediate breakthrough; no VCM adsorption was evident.
(5) Meteriala submitted by L. Chandler for ev<iatlon as VCM adsorbants.
(6) Runs 62 - 71 and all future experiments were made with our new Bendlx Total Hydrocarbon Analyzer.
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of the measurements are to be established in the operating instruction. Each, measurement point must be measured at least one time per shift. 4.4. Safety procedures in the cleaning of polymerization autoclaves.
Units and processes are so fashioned that cleaning processes in the auto claves are necessary as seldom as possible. Cleaning works by hand are to be extensively excluded. 4.4.1. Mechanized cleaning without entering of the autoclaves. 4.4.1.1. Before the opening of autoclaves, it is to be insured by suitable precautions, e.g. by evacuation, by rinsing with water, by ventilating, by the wearing of protective breathing apparatuses that the personnel are not exposed to an health endangerment by vinyl chloride. 4.4.1.2. Cleaning apparatuses, e.g. mechanically driven spray units, if possible are to be introduced into the container by mechanical apparatuses and to be operated from the outside with covered manhole. 4.4.1.3. If cleaning apparatuses, e.g. spray apparatuses held by hand, are inserted in opened manhole, it.is to be insured by suitable precautions, e.g. by evacuation, by rinsing with water, by ventilating, by the wearing of pro tective breathing apparatuses that the attendant is exposed to no health
4.4.2. . Manual..cleaning with, entering of the autoclaves. 4.4.2.1. Before the manual'cleaning, subject to the regulations'of section 4.4.2.2 iyWechanized deeming is to be carried out according to Section 4.4.1.
-
4.4.2.2. If a mechanized cleaning is not possible stipulated by the process, e.g. in mass polymerization with mischarges, a manual cleaning can be carried out. Since with a cleaning or post-cleaning vinyl chloride can be liberated from gas inclusions in the crusts, the following precautions are to be taken: 4.4.2.2.1. Before the entering and during the working in the inside, the autoclaves are to be ventilated. The air must be introduced in such manner
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that the entire autoclave is sufficiently ventilated. As a rule, the air
should be exhausted at the bottom of the container. The effectivness of the
ventilation is to be checked continuously by suitable control measurements
of the vinyl chloride concentration. In a post-cleaning, continuous measure
ment can be relinquished if it is proven that health-endangering vinyl chloride
concentrations do not occur.
4.4.2.2.2. With the occurrence of health-endangering amount of vinyl chloride,
the personnel must immediately leave the autoclaves.
4.4.2.2.3. If the occurence of health-endangering amounts of vinyl chloride
can not be hindered by ventilating, e.g. in mischarges, protective breathing
apparatus independent of the surrounding atomsphere must be worn. The same
is true for cleaning with solvents.
4.4.2.3. The duration of the entry is to be limited. The entry time for
each person should not exceed 4 hours in two seccessive shifts.
4.4.2.4. In all manual operatings in the autoclaves, tight protective gloves
and tight footgear must be worn.
5. First aid
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5.1. If a person who deals with vinyl chloride complains concerning health
.disturbance^ \a.-.dOGtb'r is-' .to; .be .called .-immediately. fop.* consultation.- The ..
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/ .' '* T. A, .. .*! .%*. * ***.* *` *; *, .,,. . .* K*9 *.- <If*,
doctor is to be made aware of the fact that he has been working with vinyl
chloride.
5.2. Wit^tiuiRlte poisoning by vinyl chloride, the victim is to be brought as sfc" i-';,
rapidly u possible into the fresh air or into a well ventilated room. Clothing
pieces contaminated with vinyl chloride are to be taken off and removed from
the room. To avoid chilling, the victim is to be wrapped in blankets. A doctor is to be called immediately! 5.3. The victim is to be brought into a stable sitting position (without danger of suffocation) ,* The victims must not be left unattended if at all
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possibleI 5.4. rf the victim is not breathing, an artifical breathing is induced immediately by suitable means, is possible by artificial respiration (mouth to mouth, or mouth, to nose). If an oxygen breathing apparatus is present, the respiration is to be continued with this. With circulation stoppage, the out side heart massage is to be carried out along with the artificial respiration.
*
However the latter may be carried out only by such helpers who have obtained a special instruction in this method. The remedial measures are to be con tinued during the transport or until the arrival of a doctor. 5.5. No liquid may be introduced to the unconscious I 6. Industrial medical Precautionary Investigations
The employer may employ only persons in the operations and plant areas according to number 1 which have been evaluated as suitable on the basis of industrial medical precautionary investigations. The investigations are to be carried out according to the rules for industrial medical procautionary investigations of the Employer's Liability Insurance Association of the Chemical Industry.
24432.008