Transcript Understanding Moisture Barriers and the Breathetex Problem

A Comparative Analysis of Glove
Permeation Resistance to Paint
Stripping Formulations
Jeffrey O. Stull, International Personnel Protection, Inc.
Richard W. Thomas, TRI/Austin, Inc.
Lawrence E. James, BASF Corporation
Scope
• a multiphase study was undertaken to
evaluate how several types of gloves resist
multi-chemical based paint stripping
formulations
Background
• Paint stripping involves prolonged,
continuous contact with chemical solvent
mixtures
• Conventional paint strippers include:
– methylene chloride, methanol, isopropanol,
acetone and toluene
• New strippers include less volatile chemicals:
– N-methylpyrrolidone, d-limonene, -butyrolactone,
and dibasic esters
Background
• Relatively little information is available to
guide the end user in selecting the gloves
against paint strippers
• Basing glove selection on individual mixture
components does not account for possible
synergistic mixture permeation
Approach
• 20 different glove styles evaluated
• 7 different surrogate formulations created
• 4 different phases
–
–
–
–
Phase I: degradation screening
Phase II: continuous contact permeation testing
Phase III: intermittent contact permeation testing
Phase IV: permeation testing against selected
actual paint stripping formulations
Surrogate Paint Strippers
(I) Methylene chloride based
Methylene chloride (80%), Acetone (10%), Toluene (4%),
Methanol (3%), Isopropanol (3%)
(II) Methylene chloride/acetone/toluene/methanol based
Methylene chloride (30%), Toluene (26%), Acetone (22%),
Methanol (22%)
(III) Acetone/methanol/toluene based
Acetone (46%), Toluene (35%), Methanol (19%)
(IV) N-methylpyrrolidone based
N-methylpyrrolidone (75%), d-Limonene (25%)
Surrogate Paint Strippers
(V) N-methylpyrrolidone (< 50%)
N-methylpyrrolidone (50%), -Butyrolactone (28%), Exxate
600 Solvent (17%), Ektapro EEP (5%)
(VI) Dibasic ester/NMP based
Dibasic ester blend (55%), N-methylpyrrolidone (36%),
Dipropylene glycol methyl ester (9%)
(VII) Dibasic ester based
Water (74%), Dimethyl adipate (23%),
Dimethyl glutarate (3%)
Commercial Paint Strippers
Formulation Commercial Paint Stripping Formulations
Klean Strip KS-3 Premium Stripper
I
Zip-Strip Paint & Varnish Remover
Savogran Strypeeze Original
II
National Solvent Liquid Stripper
Klean Strip Liquid Remover
III
Parks Furnitute Remover
Savogran Biodegradable Strypeeze
IV
Specialty Env. Tech. Citristrip
National Solvent Liquid Ultra Safe Stripper
V
Klean Strip Wood Finishers Pride Varnish Stripper
Pyrox Safe Stripper
VI
Parks Pro Stripper II
VII
3M Safest Stripper
Glove Selection Criteria
• Variety of different glove polymers
– Butyl rubber
– Natural rubber
– Neoprene
– Nitrile rubber
– PVC
– Polymer combinations
• Permeation resistance against paint stripping
formulation chemicals
• Unsupported gloves only
• Some gloves available to consumers
Glove Selection
 North Butyl Rubber Style B-161
 Guardian Butyl-Standard
 Comasec Butyl Plus
(Butyl/Neoprene overdip)
 Ansell-Edmont Neoprene Style 29845
 Pioneer Neoprene Style N-44
 Pioneer Technic Neoprene Style
NS401
 Ansell-Edmont Nitrile Style 37-165
 Wells Lamont Nitrile Style 178
 Best Nitrile Nitrosolve
 Best N-Dex Style 9005 (thin nitrile)
 Ansell-Edmont Snorkel PVC Style
4-414
 Boss PVC Style 1FP2714
 Pioneer Disposable Vinyl
 Ansell-Edmont Nat.Rub. Style 392
 Best Natural Rubber Value Master
 Thompson & Formby Refinishing
Gloves
 Pioneer Strip&Stain Style E194
(Nat/Neo/Nit )
 Best Chem Master (Neop./Nat.
Rub.)
 Comasec Multiplus (PVC/Nitrile)
Degradation Testing
• Industry practice (no standard available)
–
–
–
–
One sided contact
4-hour exposure
Measurement of weight/thickness changes
Visual observation ratings (swelling, discoloration,
curling, delamination, and deterioration)
• “0” - no effect
• “1” - mild or moderate effect
• “2” - severe effect
Permeation Testing
• Standard Test Method
– ASTM F 739 (continuous contact)
– ASTM F 1383 (intermittent contact)
• Test Parameters
–
–
–
–
–
4-hour duration
room temperature (25 + 2oC)
splash collection method
GC/FID for formulations I - III
GC/MS for formulations IV - VII
Permeation Testing
• Intermittent contact
approach
• Test measurements
Permeation
Rate
– 5 minutes chemical exposure
– 10 minutes purge
– Breakthrough time
(normalized)
– Permeation rate
– Determined for each mixture
component
Time
Overall Results
Degradation screening
Continuous
permeation testing
Intermittent
permeation testing
• 7 glove styles show best
degradation resistance
• Continuous permeation testing
shows longer BTs for plastic
laminate and butyl gloves
• No improvement for intermittent
permeation testing
• Permeation of gloves by
Testing against commercial
commercial strippers consistent
paint strippers
with surrogate strippers
Degradation Criteria
• Acceptance
criteria
– Weight change
< 25%
– Thickness change
< 25%
– Overall rating < 3
– No penetration of
test specimens
Degradation Weight Change
Form. A B C D E F G H I J K L M N O P Q R S V
I
0
II
III
IV
0
d
V
0
d
VI
0
d
VII
0
0
< 25%
25 – 50%
> 50%
d dissolved
Degradation Test Results
• Gloves failing against one formulation
– Glove E (4H glove); Glove J (North Butyl B-161),
Glove P (Comasec Butyl Plus)
• Gloves failing against two formulations
– Glove S (Guardian Butyl-standard)
• Gloves failing against four formulations
– Glove G (Pioneer Strip&Stain), Glove H (Pioneer
Neoprene NS 401), Glove K (Thompson & Formby
Refinishing gloves)
Permeation Test Results
Lowest Breakthrough Time (minutes)
Glove
Chemical
E
P
S
J
K
I
MeCl2
>240
30
30
60
15
II
Acet.
>240
150
60
180
<15
III
MeOH
>240
180
180
>240
15
IV
NMP
>240
>240
>240
>240
60
V
NMP
>240
>240
>240
>240
90
VI
NMP
>240
>240
>240
>240
180
E - Safety 4; P - Comasec Butyl Plus; S - Guardian Butyl
K - North Butyl B-161, K - Thompson & Formby Refinishing
VII
DMG
>240
>240
>240
>240
210
Comparison of Permeation
Chemical
Form.
MeCl2
I
NMP
V
Glove
P
S
J
K
K
H
M
Breakthrough Time (min)
Continuous
Intermittent
30
60
30
30
60
75
15
15
90
45
45
15
30
30
Actual Paint Stripper Results
Lowest Breakthrough Times (minutes)
Challenge
Comp. %
Methylene Chloride
Form. I
80
Stripper I-A
76
Stripper I-B
75
N-Methypyrrolidone
Form. IV
75
Stripper IV-A
67
Stripper IV-B
37
Glove E
Glove J
Glove K
> 240
15
15
60
< 15
15
15
< 15
< 15
> 240
> 240
> 240
> 240
> 240
180
90
90
60
Conclusions
• Multi-stage testing program useful for
determining permeation resistance
• Glove permeation resistance did not always
improve with decreasing exposure
• Surrogate paint strippers do not always
emulate actual stripper permeation
• Paint strippers with volatile solvent permeate
quicker than those containing NMP or dibasic
esters
Acknowledgement
This work was supported by a grant from the
N-Methylpyrrolidone Producers Group, Inc.,
Washington, D.C.