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Issue
Do current Center policies adequately address potential adverse health
effects of medical glove powder?
Background
The Food and Drug Administration (FDA), as well as other state and
federal agencies, has received requests to ban the use of glove powder. It
has been suggested that experimental and clinical studies demonstrate that
glove powder on medical gloves can enhance foreign body reactions,
increase infections and act as a carrier of natural latex allergens. The
National Institute of Occupational Safety and Health (NIOSH) recently
issued a safety alert recommending the use of powder-free, reduced protein
content latex gloves to reduce exposure to natural latex proteins
(allergens).
For the purposes of this document, total particulate matter [glove
powder] includes dusting or donning powders, mold-release compounds, and
manufacturing debris. Dry lubricants such as cornstarch, silicone etc.,
are used to make donning gloves easier and to prevent gloves from sticking
together during the manufacturing process. Cornstarch, which meets the
specification for absorbable dusting powder in the United States
Pharmacopoeia (USP), is the most common lubricant for patient examination
gloves. Only absorbable dusting powders that have an approved Premarket
Approval Application (PMA) or New Drug Application (NDA) may be used for
lubricating surgeons gloves. There are no comprehensive studies of the
amount of absorbable dusting powder used on powdered gloves. It is
estimated that amounts of total particulates may range from 120 to 400 mg
for a medium size powdered glove. [Appendix A]
Glove powder is composed of particles, thus, issues related to biologic responses to foreign bodies apply to both natural rubber latex (NRL) and synthetic gloves. Industry conversion from talcum powder, a non-absorbable lubricant, to absorbable cornstarch has greatly reduced the formation of granulomas. Adhesions of peritoneal tissue after surgery are associated with foreign bodies and remain a concern. The issue of the level of micro-organisms (bioburden) on gloves has been raised under various circumstances. However, evidence that bioburden and powder are related do not exist at this time. [Appendix B]
Experimental and clinical data demonstrate that: natural latex proteins
are allergenic, natural latex proteins bind to cornstarch, aerosolized
powder on NRL gloves is allergenic and can cause respiratory allergic
reactions. These published studies support the conclusion that airborne
glove powder represents a threat to individuals allergic to natural rubber
latex and may represent an important agent for sensitizing non-allergic
individuals. There are also published data (although limited) and clinical
experience that cornstarch powder on NRL gloves may also be a contributing
factor in the development of irritation and Type IV allergy. [Appendix B]
There are alternatives to dusting powder for lubricating natural rubber
latex surfaces. The most common method is chlorination. Chlorine reacts
with the natural rubber latex surface to reduce the natural tackiness,
eliminating the need for adding dusting powder. The extra washing
performed during the chlorination process provides an added benefit by
also greatly reducing the level of soluble natural latex proteins.
However, chlorination affects some of the mechanical and physical
properties. Gloves made from alternative materials, not containing natural
allergens, are available, but none possess the unique mix of properties
offered by natural rubber latex. [Appendix C]
Market availability must be factored into any policy decision regarding
medical glove powder. The large majority of medical gloves used in the
U.S. are imported. In 1996, 20.8 billion medical gloves were imported into
the U.S.: 90% natural rubber latex and 10% nonlatex. Of the 90% that were
natural rubber latex, 20�% were powder-free and chlorinated. Only a
small number of manufacturers are using a process other than chlorination
to produce powder-free gloves. A rapid increase in the demand for
non-powdered gloves could result in products with poor barrier integrity
and/or unacceptable shelf life entering the U.S. market. In addition to
concerns about glove quality, most alternatives to glove powder currently
would entail substantially increased costs to the U.S. health care system.
[Appendix D]
Conclusions
(1) The major adverse impact of glove powder appears to be its contributing role in natural rubber latex allergies.
(2) Glove powder acts as an airborne carrier of natural latex proteins.
(3) Exposure to airborne natural rubber latex allergens can be most
effectively reduced by considering both the level of natural latex
proteins and the amount of glove powder on medical gloves.
Options
Immediately banning the use of glove powder would cause a market
shortage that could result in inferior products and increased costs. Doing
nothing to address the problem of airborne allergens which are carried by
glove powder, would appear to be an abrogation of FDA's responsibility to
protect public health. It appears that neither extreme offers a viable
option. The following options are offered for consideration:
Pro:
Con:
Pro:
Con:
Author: Mel Stratmeyer
Recommendations
These recommendations represent activities either currently ongoing or
which could be initiated. Detailed action plans required to accomplish
these recommendations are not addressed in this document, but will need to
be developed.
Glove Powder
Protein
Barrier Properties
Labeling
* In addition to ASTM, work with other voluntary standards organizations when appropriate.
Appendix A
History
Since the introduction of surgical gloves to the operating theater in
1889, various types of lubricating materials have been used to aid in
glove donning. These range from various wetting techniques to the use of
dusting powders such as a mixtures of Lycopodium spores and talc, talcum
powder alone, calcium carbonate, and different types of starch products.
The first lubricant used was a powder made of Lycopodium spores (ground
pines or club moss). This lubricant was quickly accepted and was used
worldwide until the 1930's, when surgeons realized that it caused
granuloma and adhesion formation. Lycopodium was toxic and became
unacceptable for use as a glove lubricant. As a result, talcum powder
(hydrous magnesium silicate), a non-absorbable lubricant, was introduced
as a replacement for Lycopodium spores. In the 1940's talcum powder was
also identified as a cause of post-operative complications such as
granuloma and adhesion formation. In 1947 a modified cornstarch glove
powder was introduced to the medical community as an absorbable and
non-irritating powder. By the early 70's, many surgical glove
manufacturers replaced talc with the modified cornstarch.
Cornstarch, which is absorbable through biological degradation, that
meets the specification for absorbable dusting or dusting powder in the
United States Pharmacopoeia (USP) is the most common lubricant for patient
examination gloves. The absorbable dusting powder used on medical gloves
is a chemically cross-linked cornstarch to which no more than 2% of
magnesium oxide is mixed to prevent caking or turning to paste. Talc,
cotton flock, and other non-absorbable materials are not acceptable as a
lubricating, dusting or donning powder. ASTM* D 3578-95
(Standard Specification for Rubber Examination Gloves), D 5250-92
(Standard Specification for Polyvinyl Chloride Gloves for Medical
Application) and ASTM
D 3577-91 (Standard Specification for Rubber
Surgical Gloves) require the inside and outside surfaces of medical gloves
to be free of talc.
In addition to dusting powder, other lubricants may also be used in the
manufacturing process. Latex and some polymers are tacky and gloves made
of these materials stick to the mold or former. A mold-release lubricant
such as calcium carbonate or a mixture of calcium carbonate and cornstarch
is used to enable the removal of gloves from molds. The other side of the
glove may be coated with a donning lubricant, such as cornstarch or
silicone, to make donning gloves easier and to prevent gloves from
sticking during the manufacturing process.
Over the past three years, FDA has received requests to ban the use of
all glove powders. These requests have been based on repeated clinical and
experimental studies reporting that cornstarch on surgical gloves can
damage tissue's resistance to infection, enhance the development of
infection, serve as a potential source of occupational asthma, and provide
a source of natural latex protein exposure to natural latex allergic
individuals. The issues regarding the use of glove powder, except for the
transport of natural latex protein allergens, apply to the use of glove
powder on both natural rubber latex and synthetic gloves.
As a result of continuing concern over adverse reactions to cornstarch,
in 1971 FDA required manufacturers to place a warning label on the glove
packages. The warning label stated, "CAUTION: After donning, remove
powder by wiping gloves thoroughly with a sterile wet sponge, sterile wet
towel, or other effective method." Studies have shown that efforts to
remove the cornstarch from the surgical gloves using washbasins and wet
cloths are unsuccessful. It has been reported that such efforts have led
to added clumping, creating even less absorbable aggregates.
Because of multiple concerns about the adverse health effects of all
particulate matter from the surface of medical gloves (Appendix B), there
is a recognized need for "low powder" and "powder-free"
glove products. Particulates found on the gloves can include dusting
powder, mold- or former-release compounds, lint, dust, colloidal solids,
cotton, cellulose, wood fibers, metal, paper particles from packaging, and
manufacturing debris. The most common particulates on gloves are dusting
powder and former-release compounds added by manufacturers. Gloves with
sufficiently low amounts of residual particulates are referred to as "powder-free",
or "powderless." Several brands of powder-free examination and
surgical gloves have been developed, some using powder-free manufacturing
processes. Gloves labeled as "powder-free" may be coated with a
polymer or added powder may have been removed through washing and
chlorination. Although gloves are labeled as "powder-free", they
contain various amounts of powder or particulates matter. FDA has adopted
2 milligrams particulate weight (based on the ASTM test standard D
6124-97) per glove powder or less as a basis for approving powder-free
gloves. Alternatively, the Office of Device Evaluation (ODE) has accepted
a negative iodine test to support "powder-free" claims. However,
virtually all glove manufacturers provide particulate weight. For
comparison purposes, a medium size powdered glove, depending on the
processing, contains about 120-400 milligrams of residual debris,
former-release and dusting powder.
Problems associated with the use of powder-free examination and surgical gloves include concerns about the particulate levels remaining on the gloves, use of chlorination, and the treatment with other chemical agents that may have a deleterious effect on the physical properties and/or performance of the gloves.
Surgeon's Gloves
Surgeon's gloves, defined as "a device made of natural or
synthetic rubber intended to be worn by operating room personnel to
protect a surgical wound from contamination
" are classified as
Class I medical devices under 21 CFR 878.4460.
Absorbable dusting powder for lubricating a surgeon's glove is
classified by the FDA General and Plastic Surgery panel under 21 CFR Part
878.4480 as a class III device which requires an approved PMA. Only
absorbable dusting powders from manufacturers that have an approved PMA or
NDA (before it was regulated as a device) may be used on surgeon's gloves.
Powder used for lubricating examination gloves has not yet fallen under
the same regulatory guidelines as those for surgical gloves.
Patient Examination Gloves
Patient examination gloves were classified as Class I medical devices
in the October 21, 1980 Federal Register under 21 CDR 880.6250 and
amended in the January 13, 1989 Federal Register. The amendment
revoked the Premarket Notification 510(k) and Good manufacturing Practices
(GMP) exemptions previously designated for examination gloves.
The description for patient examination gloves made of natural rubber,
vinyl, or other materials given in regulation 880.6250 define the patient
examination glove as "
a disposable device intended for medical
purposes that is worn on the examiner's hand or finger to prevent
contamination between patient and examiner."
Powder used for lubricating examination gloves should meet the USP
monograph for absorbable dusting powder or be shown to be equivalent in
terms of safety and effectiveness. The 510 (k) must state the type,
specifications and source of powder or other dusting lubricant used on the
gloves. ASTM is currently developing the Standard Test Method for Residual
Powder on Medical Gloves (D 6124-97). The standard does not include a
weight limit for the total powders on powder-free medical gloves.
Quality System Regulation
FDA published, in the Federal Register (FR) on October 7, 1996, a
revised GMP or Quality Systems (QS) regulation which contains requirements
on the control of naturally occurring material on medical devices such as
adverse protein on gloves.
The new QS regulation has several revised definitions, such as the
definition for manufacturing materials in �0.3(p) which is:
"Manufacturing material means any material or substance used in or used to facilitate the manufacturing process, a concomitant constituent, or a byproduct constituent produced during the manufacturing process, which is present in or on the finished device as a residue or impurity not by design or intent of the manufacturer."
A concomitant constituent is an ingredient that naturally exists in a
component of a medical device or that exists in a manufacturing material
used in, or used to facilitate, the manufacturing process. The allergenic
or adverse proteins that naturally occur in the natural rubber latex
component of medical devices are concomitant constituents.
Specific requirements for the use and removal of manufacturing
materials are in �0.70 Process Controls where �0.70(h)
states:
"Manufacturing material. Where a manufacturing material could reasonably be expected to have an adverse effect on product quality, the manufacturer shall establish and maintain procedures for the use and removal of such manufacturing material to ensure that it is removed or limited to an amount that does not adversely affect the device's quality. The removal or reduction of such manufacturing material shall be documented."
Thus, to meet direct health care concerns and to meet GMP requirements,
water-soluble proteins on medical devices have to be limited by
manufacturers when such proteins can be expected to have an adverse effect
on patients and users.
Authors: Terrell
Cunningham, Andrew Lowery
Appendix B
I. Biological Reactions
Glove dusting powder is composed of particles and there are predictable
biological reactions to particles. The bulk of the glove powder is
cornstarch, which is a resorbable particle and reactions are expected to
be minimal and of short duration. This section reviews the nature of the
biological reactions and the available information on these reactions to
glove powder.
General Reports
A review article appearing in the peer reviewed literature in 1990,
provides background information and an excellent summary of the problems
associated with the use of glove powder (1). Powders
have been demonstrated to cause inflammation and granulomas but a much
higher dose of cornstarch is needed compared to talc. This study also
cites a number of other substances such as suture material, gauze fluff,
and cellulose that may cause these biological reactions more frequently
than does cornstarch which is the major particulate component of glove
powder. Studies on changes in starch processing were also examined and
autoclaved starch is rapidly resorbed (48 hrs. in rat peritoneum) and
irradiated starch was still present at 70 days. Studies on washing the
powder off were also reported and washing with saline clumps the powder
rather than removing it.
There are additional general reports which do not contribute much to
the discussion and do not provide recent references (2, 3).
Zaza et al (4) report a good study on natural latex
sensitivity with some reference to glove powder. There was no difference
in sensitivity incidences when the different kinds of gloves were
compared. However, nurses with cosmetic sensitivity had higher incidence.
The availability and widespread use of cosmetic powders with talc and with
cornstarch is cited and is an important issue in evaluating the risks
associated with glove powder.
Contamination of Surgical Wounds and Peritoneal Adhesions
Contamination of surgical wounds and peritoneal adhesions are the
biological reactions most frequently cited in the literature. There were
pleas for powder-free gloves (5, 6) and indications
that glove powder does contaminate the wounds since washing of gloves is
ineffective (6).
The issue of peritoneal adhesions from the use of powdered surgical
gloves is the major issue in the literature and most of these studies are
from Europe (11-12). The studies are well documented,
and the assumption is that the glove powder is cornstarch and not talc.
But this is not really proven in all cases. Peritoneal adhesions following
surgery are a major complication with estimates that 60�% of
intestinal obstructions are due to adhesions. The presence of foreign
bodies is a major cause of these adhesions and the reactions are likely to
be to sutures. However, the overall recommendation is to keep foreign
bodies out of the operative area and this includes glove powder.
Powder-free gloves are recommended and some available gloves or
methodologies for preparing gloves are provided.
One European study had some interesting data and is the only study to
have numbers that reflect incidence of reactions to glove powder (10).
In 1991-1993, 448 patients were evaluated and peritoneal granulomas were
found in 26% of the patients. There were suture granulomas in 25% of the
patients and the surgeons of 309 patients used powdered gloves. Of these,
14 (5%) had documented starch granulomas. The overall conclusions were:
the more operations on a patient; the more likely granulomas would appear.
These are related to foreign bodies with sutures being the major cause.
However, they do advocate avoiding depositing glove powder into the wound.
Experimental Studies
Some very interesting animal studies, mostly done in Europe, examined glove powder. The overall conclusions can be summarized that glove powder consists of particles and there is a biological response to those particles. The presence of a foreign body increases the risk of infection and cornstarch is a foreign body. However, of all the foreign bodies studied, cornstarch promotes the least
reaction (13-16).
Other Concerns with Glove Powder
There are miscellaneous reports of glove powder being left behind on
devices or instruments (17, 18).
When this literature survey began, it was anticipated that pulmonary
complications and associated granulomas would be the major issue. This
does not appear in the literature and pulmonary complications in patients
are not described.
Powder and cancer
Chronic inflammatory responses are of concern and there is some
continuing thought, but no evidence, that a site of chronic inflammatory
responses may be more prone to developing a cancer. In addition, there is
always the concern of foreign body carcinomas (19)
demonstrated in rodents. The biggest issue with granulomas from the
chronic inflammatory response is that they mimic cancers and there may be
a misdiagnosis. There is no evidence of genotoxicity, mutagenicity, or
carcinogenicity with cornstarch. Granulomas may mimic carcinomas and
biopsies may be necessary for decision making (7).
General Issues with Cornstarch
Cornstarch is a powder of particles and as such, the reactions are as
those expected to particles. However, since cornstarch is a biodegradable
particle, chronic responses are rare. Any modification of cornstarch that
prolongs its degradation will increase the magnitude of the reactions. Any
contamination with talc will greatly increase the biological reactions.
Cornstarch is a common substance in every day life. Powders and cosmetic
products with cornstarch are available over-the-counter (OTC) in all
stores. In addition cornstarch is common in baking and cooking. There are
numerous reports of reactions to powders in cosmetics and in the work
place that are not associated with health care (20, 21).
Bioburden and Powder
The issue of the level of micro-organisms on non-sterile medical gloves
has been raised under various circumstances. The only study available on
bioburden is an ongoing FDA funded study. Progress reports indicate
organisms of pathogenic potential were found on examination gloves in some
instances. However, the issue of powder should be kept separate from the
bioburden since there is no evidence that bioburden and powder are
related.
Surgeons gloves are sterilized and thus, there is no remaining living
bioburden on the finished product. Surgeons gloves, which are often highly
powdered for ease in donning over wet hands, are routinely washed prior to
use and the methods of washing and the effectiveness of the procedure are
not well described and remain an area of concern for powder and bioburden
from washing contamination.
Powder Free Gloves
Articles on the availability and suitability of powder-free gloves
appeared with pleas to surgeons to use them (22, 23).
Review of Biological Reactions to Powdered Gloves
Author: Katharine Merritt
II. Prevalence and health impact of Type I allergy
to natural rubber latex (NRL)
Millions of health care workers, including groups such as physicians, nurses, respiratory technicians, and phlebotomists, use NRL gloves on a daily basis. The advent of universal precautions policies dramatically altered the usage of NRL gloves by the health care workers. Prior to universal precautions, gloves were only employed in instances when the patient was known to be infected with a given infectious agent, such as the hepatitis B virus. A multi-state study by Kaczmarek et al (24) found 100% compliance with universal precautions policies by the health care facilities in the study. Actual observed compliance by health care workers during routine procedures that could involve contact with patient body fluids was substantial, but not universal, ranging up to 92% during arterial blood gas procedures. Although many devices employed in the health care environment include natural latex, it is clear that NRL gloves are a crucial source of exposure to natural latex allergens for many health care workers.
Health care workers are recognized as comprising a high-risk group for
natural latex allergy. Every study of health care workers has demonstrated
an appreciable prevalence of natural latex sensitization as evidenced by
natural latex-specific IgE antibodies and/or positive skin tests for
natural latex allergy. For example, a study by Kibby and Akl (25)
reported that 8.2% of hospital employees were skin test positive for
natural latex reagent and 6.7% of them had class II or higher ELISAs for
natural latex璼pecific IgE antibodies. A national, multi-center study
by Kaczmarek et al (26) found that 5.5% of health care
workers had natural latex-specific IgE antibodies. Nine point nine percent
of the natural latex skin prick tests of 101 physicians were positive in a
study by Arellano and colleagues. (27) Operating room
nurses have also been studied. A study by Lagier et al (28)
reported a prevalence of 10.7% natural latex skin prick test positivity
among 197 operating room nurses. Finally, in a study that included dental
personnel with hospital employees, Yassin et al (29)
observed a prevalence of natural latex skin prick test positivity of 17%.
The general population is exposed to natural latex from a variety of
sources, including consumer products such as natural latex balloons, as
well as medical devices such as barrier contraceptives and the NRL gloves
of health care providers, e.g., dental personnel. The prevalence of
natural latex allergy among the general population has been estimated to
range between 1% and 6%, lower than the corresponding range for health
care workers. The upper end of the range is based on a study of blood
donors in southeastern Michigan (30). This study has
been questioned because blood donors may not be fully representative of
the general population. There is a consensus that further study is
warranted. The CDRH Epidemiology Team is currently conducting a
seroprevalence study of natural latex-specific IgE antibodies among NHANES
(National Health and Nutrition Examination Survey) III participants. This
study, with an estimated sample size of several thousand individuals, will
substantially increase the understanding of the epidemiology of natural
latex allergy among the general population.
Author: Ron Kaczmarek
III. Role of glove powder in allergic reactions to
natural rubber latex (NRL)
Clinical studies
A number of publications since the mid 1980's, reported respiratory
problems and asthma like attacks in hospital employees and patients. The
problem was ascribed to inhalation of airborne natural latex allergen in
the areas of heavy use of powdered gloves (31-39).
Affected individuals were frequent users of medical gloves, mainly nurses
and physicians. The reactions to airborne natural latex allergens were
also reported in other occupationally exposed individuals (38,
40) and/or environmentally exposed individuals (35).
It is estimated that roughly 30% of natural latex sensitive individuals
develop respiratory problems (31), and that
aerosolized glove powder in areas of frequent glove use may affect direct
users as well as those who do not use natural latex products, but are in
the same areas (41). Furthermore, a recent study from
Finland demonstrated a rather low prevalence of respiratory allergy
reactions in one hospital, in which powder-free gloves were used for an
extended period of time (42). The conclusions
regarding the role of glove powder in the above clinical reports were
based on medical histories of individuals presenting symptoms, on positive
skin tests and, in some cases, on positive inhalation test.
Binding of natural latex proteins to cornstarch powder
The propensity of cornstarch to bind natural latex proteins was studied
in detail in two recent publications. Three preparations of cornstarch: a)
clean, unused dusting powder, b) cornstarch exposed to natural latex
protein extracts and c) cornstarch extracted from powdered gloves, were
evaluated for total protein levels (43) and for
allergenic protein levels (43, 44). Unexposed
cornstarch contained no allergenic proteins, while both natural latex
exposed cornstarch preparations had a significant amount of allergenic
proteins bound to the particles. The results of both studies clearly
demonstrate that cornstarch indeed binds allergenic proteins, which can
not be detached by simply washing the powder. These findings support the
causal relationship between asthmatic reactions in individuals with
natural latex allergy and the exposure to airborne particles from NRL
products.
Airborne glove powder as an allergen carrier
Several papers describe measurements of airborne particle levels in the
environment with frequent use of NRL gloves. Airborne particles were
collected through filters and analyzed for allergen content.
Airborne natural latex allergen levels were evaluated in the
laboratories using either powdered gloves or powder-free gloves (45).
This study showed much higher allergen levels ranging from 39-311 ng/m3
in laboratories where powdered gloves were used in comparison with the
levels of less than 20 ng/m3 in laboratories where powder-free
gloves were used. More detailed measurements of the airborne allergen were
done in the operating rooms, comparing airborne allergen levels on days
when high-allergen gloves were used with days when low-allergen gloves
were used and finally with no surgery days (46). The
median allergen level of 13.7 ng/m3 on high-allergen glove
days was down to 1ng/m3 and 0.6 ng/m3 on low
allergen glove days or no surgery days, respectively. In the environment
where powdered gloves were used, large quantities of allergen could also
be collected from personnel lab coats and scrub suits (47).
These studies demonstrate that the level of airborne allergen is
directly related to the frequency of powdered glove usage in particular
areas and to the level of allergen/powder on the gloves used.
Respiratory problems in natural latex allergic individuals
A number of published papers provide direct evidence that natural latex
protein allergens, bound to corn starch particles are a cause of
respiratory allergic reactions and asthma like attacks. This has been
documented by the bronchial provocation test, performed by exposing
allergic individuals to inhalation from powders on NRL gloves. A change in
the Forced Expiration Volume (FEV), a measure of pulmonary function, is an
indication of intensity of the reaction to allergen.
Patients who developed rhinitis, conjunctivitis and dyspnea when in the
operating room theater or in other hospital environments with a heavy use
of NRL gloves, were evaluated for natural latex allergy (medical history,
specific IgE antibodies, skin test). After positive diagnosis of existing
allergy to natural latex proteins, patients underwent the bronchial
provocation test with airborne powder particles from NRL gloves. Test
subjects were asked to handle powdered NRL gloves and powdered non-NRL
gloves while their respiratory functions were monitored. They could handle
up to 20 pairs of non-NRL gloves inhaling the powder particles, without
any respiratory symptoms, while the same individuals, after handling as
few as one pair of NRL gloves started to develop airway resistance (48).
Furthermore, the preparation of glove powder from NRL gloves tested by
bronchial provocation test and skin test, demonstrated positive reactions
in both cases (49). In another study, a provocation
test with clean cornstarch that has not been in the contact with a natural
latex product did not provoke any respiratory reaction, while in the same
individuals, powder from NRL induced asthmatic reaction (50).
The control individuals with no natural latex allergy, did not develop any
symptoms during provocation with allergenic powder.
In a more recent well controlled study (51), the
bronchial provocation test was performed with the extracts from
powder-free surgical gloves, from powdered surgical gloves and with a
clean cornstarch powder extract. A clean cornstarch powder caused no
bronchial reaction in sensitized subjects. Exposure to a nebulized
powder-free NRL surgical glove extract induced immediate
bronchoconstriction in two of four tested subjects. However, when
nebulized powdered glove extract was tested, a 1:10 dilution of the
extract induced bronchoconstriction in all four tested subjects and the
intensity of the reaction was the same as with undiluted powder-free glove
extract.
A recent study from Belgium (52) revealed that 4.7%
of hospital personnel were allergic to natural latex, confirmed by medical
history and skin testing. Allergic individuals were pretested for
bronchial responsiveness and then exposed to the provocation test with
powdered NRL gloves. A total of 58% of allergic participants or 2.6% of
the entire surveyed population developed an asthmatic reaction, while the
provocation with vinyl glove powder did not cause any change in bronchial
functions.
In summary, the studies reviewed above lend support to the conclusion
that airborne glove powder may represent a threat to individuals allergic
to natural latex proteins. Avoidance of use of natural latex products by
such individuals may provide insufficient protection from natural latex
proteins if they are in the environment of powdered glove use. Since there
is not current safe and effective therapy for natural latex allergy,
avoidance of all sources of natural latex allergen is the only available
therapeutic option.
Role of glove powder in irritation and contact dermatitis development
Another issue that has to be addressed is a possible causal
relationship of glove powder with the irritation and contact dermatitis
development.
It is known that cornstarch used for donning is a strong absorbing
powder and has a tendency to cause dryness of the skin leading to cracking
and itching. A compromised epithelium can have serious health
consequences. Not only that barrier properties for infectious agents are
reduced, but also in this case, chemicals used in the production of NRL
gloves and natural latex proteins can penetrate a damaged skin enhancing
chances of development of both Type IV and Type I allergy. Skin reactions
to glove powder have been observed and interpreted as irritant reactions
(53). The major factors influencing elicitation of
irritant dermatitis are dose and exposure time, and termination of
exposure is the cure. Therefore, in the case of NRL gloves, a prolonged
contact with glove powder may have serious impact on the user skin
condition.
There are no data that directly implicate cornstarch powder as a cause
of allergic contact dermatitis up to now. However, it has been reported
that nonimmune proinflammatory agents can augment the response to contact
sensitizers (54). This augmentation occurs with
subthreshold doses of both irritants and allergens and therefore,
individuals that may have not presented symptoms of either reaction, can
still react in case of a combined exposure (55).
These published data (although limited) and clinical experience
implicate that cornstarch powder on the NRL gloves, in addition to its
role in Type I allergy, may also be a contributing factor in the
development of irritation and Type IV allergy.
Author: Vesna Tomazic
IV. Medical Device Reporting (MedWatch) Database
FDA's adverse event databases rarely contain event text or coded information that would allow for comprehensive, automated tallies of reported medical glove related events. Reports cannot differentiate between events associated with either Type I or Type IV hypersensitivity reactions, including reactions to powder-free vs. powdered glove products. However, based on a review of all reports, it is possible to provide the following information summary.
As of August 27, 1997, 2,501 voluntary and mandatory incident reports
involving natural rubber latex containing medical gloves have been entered
into FDA's adverse event database. A review of database information
indicates that approximately 1,550 or 62% of these medical glove related
reports allege the occurrence of adverse events that involve allergic
reactions, including anaphylaxis. The text of these reports indicate the
occurrence of either skin reactions (Type IV or Type I) or systemic (type
I) allergic reactions of one or more health care professionals or patients
to medical gloves.
Approximately 100 or 4% of medical glove related adverse event reports
allege specific glove powder residue complaints. These reports raise
concerns regarding granuloma formation, general concerns regarding
infection risk associated with powder content, low powder content making
donning difficult, contamination with unidentified debris or insect parts,
mold growth, and high levels of powder on gloves labeled as "powder-free."
A glove powder related death report was submitted in 1986 under the
procode for surgeons' gloves. The reporter, a manufacturer, indicated that
a physician had questioned the role that glove powder could have played in
the death of a patient who experienced post-operative peritonitis related
complications.
The remaining 851 (33%) reports are primarily related to concerns
regarding product barrier integrity. However, it should be noted that
problems with degradation of the desirable physical properties of medical
gloves has also been associated with powder-free glove manufacturing
processes such as chlorination.
Author: Sharon Dillard
Appendix C
As discussed in previous sections of this report, glove powder has been
implicated in the post-operative formation of adhesions, and in some
instances, in granuloma formation. Also as discussed previously, natural
latex allergens bound to airborne glove powder are known to cause
respiratory problems for natural latex allergic individuals. Although the
use of glove powder as a dusting lubricant is very common, there are other
alternatives available. This section discusses several alternatives to
powdered NRL gloves.
Chlorinated natural latex rubber (NRL) gloves
Although lubrication of the NRL glove surface can be accomplished with
various dusting powders, the powder can be rubbed off and become airborne
during use. A more permanent method of reducing surface drag in natural
rubber latex products is known as halogenation. When carried out using
chlorine as the active element - as is commonly done with NRL gloves - the
process is called chlorination.
Chlorination of the NRL gloves is performed by immersing the gloves in
a dilute solution containing free chlorine ions. The chlorine reacts with
the natural rubber surface to reduce the natural tackiness of the natural
latex, hence eliminating the need to add a dusting powder to the glove.
After immersion of the glove into the dilute chlorine solution (usually
between 0.05�30%), the gloves are washed in water, dipped in a
neutralizing solution (e.g., 1% ammonia solution), rinsed again, and then
dried (56). This extra washing performed during and
after chlorination greatly reduces the level of extractable latex proteins
in the product. Some latex proteins are even converted to insoluble forms
during chlorination itself (57).
One significant drawback to using chlorinated NRL gloves is that some
of the mechanical and physical properties of the natural latex are
compromised. Woods et al (58) states that the
chlorination process adversely affects shelf life, grip and in-use
durability of the glove. In addition, strong odors may be present in
chlorinated gloves, as well as possible skin irritants.
An FDA study of the effects of elevated temperature on the tensile
strength of NRL gloves showed very dramatic results for powder-free
examination gloves that are believed to have been chlorinated. Various
styles of NRL gloves were placed in paper envelopes and oven-aged in air
for 7, 14, and 21 days at 70� Celsius, and then subjected to tensile
testing per ASTM D 412. (Accelerated aging in the laboratory at 70� C
is common for NRL gloves, and is one of two recommended temperatures for
aging of gloves in ASTM D 3577 and ASTM D 3578.) Five of seven powder-free
styles exhibited dramatic decreases in tensile strength after just 7-14
days at 70� C, with total decreases in tensile strength ranging from
70% to over 90% at 21 days of aging. Although the details of the
manufacture of these five styles are proprietary, it is believed that all
were chlorinated. In contrast, almost half of the powdered gloves subject
to the same conditions showed no statistically significant decrease in
tensile strength, while the remaining powdered gloves decreased a moderate
10 to 25% by 21 days of exposure (59). A progress
report from an ongoing federal璼tate contract study on NRL exam
gloves recently indicated similar results: extreme degradation of
chlorinated exam gloves observed after 14 to 21 days of aging at 70�
C (60).
Slight variations in the chlorination process are known (56,
61, 62). For example, variations in solution strength, immersion
time, neutralizing agents, time elapsed between chlorination and
neutralization, drying temperature and drying time can all influence the
effects of chlorination. Aziz (56) tested gloves
chlorinated with 0.01%, 0.03%, 0.05%, 0.1% and 0.3% chlorine solutions.
For unaged samples, tensile strength was maintained from 1 to 20 minutes
of chlorination time for all samples except those chlorinated with the
0.3% solution, in which tensile strength decreased by approximately 25%.
For samples aged 7 days at 70� C, original tensile strength decreased
slightly for up to 20 minutes of chlorination, except for the 0.3%
samples, where the tensile strength decreased by roughly 50% for 20 min.
of chlorination. For samples aged 22 hours at 100� C, original
tensile strength was maintained only for the 0.01% solution. The strengths
of the remaining samples decreased 50-95% after only 2-6 minutes of
chlorination.
Aziz also showed the higher concentrations of chlorine lead to
microscopic cracks in the surface of the natural rubber latex.
Chlorination time and solution strength also affect the color of the
finished product (longer times and higher concentrations lead to a more
yellow product). Thus, in order to avoid the potential negative effects of
chlorination, chlorine concentrations and immersion times should be
carefully chosen.
Synthetic polymer linings
Another alternative to powdered gloves is a NRL glove having a
synthetic polymer lining on the internal surface of the glove. The
slippery surface of such a lining facilitates donning of the glove.
Synthetic polymer coatings may be made of a hydrogel, silicone, or another
polymer. It appears that no shelf-life data exist to substantiate the
long-term barrier properties of synthetic polymer-coated NRL gloves.
In the case of hydrogel polymer linings, the NRL glove is dipped into a
solution of the hydrogel prior to the final curing stage of glove
manufacture. The hydrogel lining is physically bonded to the natural
rubber latex (58) and lies on the internal
skin-contacting surface of the finished product. Due to its low
coefficient of friction, the hydrogel lining facilitates donning with
either wet or dry hands (63, 64, 65).
Other approaches
From the late 1800s to the mid-twentieth century, surgeons used water
as the primary lubricating agent when donning gloves. The protective
rubber gloves utilized at that time were designed for multiple use, and
thus were pulled onto wet hands after being "sterilized" [sic]
in boiling water (58, 63, 66). Water is not an
effective glove lubricant for today's thin, close-fitting NRL gloves.
Glove liners in the form of cotton or nylon stretch gloves, or liners
made of materials designed to resist puncture, are sometimes worn
underneath NRL gloves, between the bare skin and the glove. Although
liners are not used to facilitate donning, they will provide a layer of
protection to the user, and thus reduce the risk of skin irritation. They
also reduce discomfort due to hand sweating. Gloving creams are sometimes
used to facilitate the donning of gloves and at other times, are used to
reduce the wearer's potential for skin irritation. However, if used with
powdered gloves, such glove liners and creams will do nothing to eliminate
the occurrence of airborne natural latex allergens.
Gloves made from materials other than natural rubber latex (e.g.,
synthetic rubbers or other synthetic polymers) are available, but none
possess the unique mix of properties (high elasticity and tensile
strength, excellent film-forming characteristics) found in NRL gloves (57,
66). Gloves made from some of these alternative materials, such
as plasticized PVC, include high levels of chemical additives which may
cause skin irritation and/or allergic reactions (66, 67).
Furthermore, the barrier properties of alternative glove materials must be
thoroughly examined prior to their selection for use.
Summary
Chlorination of NRL gloves is a common alternative to the use of glove
powder. Chlorination has an adverse affect on various mechanical and
physical glove properties, which may affect shelf-life. Thus, the
chlorination process should be tightly controlled. Gloves made of
synthetic materials are available, but none possess the unique mix of
physical properties offered by natural rubber latex. Synthetic
polymer-coated gloves are another possibility, but as is the case with
both NRL and non-NRL gloves, it appears that little or not shelf-life data
exist in the current literature to substantiate the long-term barrier
properties of this type of medical glove.
Author: Donna Walsh
Appendix D
In 1996, the U.S. imported 20.8 billion medical gloves, 62% of which
came from Malaysia. Since 1991, the number of medical gloves imported into
the U.S. has increased by 247%. See the table below provided by the
Division of Small Manufacturers Assistance (DSMA).
Malaysia | 3.9 | 7.6 | 9.9 | 10.4 | 11.8 | 13.0 |
Thailand | 0.9 | 1.8 | 2.0 | 1.7 | 2.2 | 3.2 |
Indonesia | 0.2 | 0.6 | 0.8 | 0.8 | 1.1 | 1.9 |
Sri Lanka | 0.2 | 0.5 | 0.3 | 0.5 | 0.6 | 0.7 |
India | 0.1 | 0.3 | 0.5 | 0.5 | 0.5 | 0.6 |
Taiwan | * | * | * | * | 0.4 | 0.3 |
China | 0.5 | 0.4 | 0.7 | 0.6 | 0.6 | 0.8 |
Others | 0.2 | 0.2 | 0.3 | 0.4 | 0.2 | 0.3 |
Total Imports | 6.0 |
11.4 |
14.5 |
14.9 |
17.4 |
20.8 |
% Increase | 90% | 27% | 3% | 17% | 20% |
* Number of imports not enough to be included in top
seven countries in this table.
These numbers include medical gloves of all types: NRL, powder-free
NRL, and non-NRL. In 1996, the distribution by type was 90% NRL and 10%
non-NRL. Of the 90% natural rubber latex, 20-25% were powder-free latex
and chlorinated. Only a small number of manufacturers are using a process
other than chlorination to produce powder-free gloves.
Malaysia is the largest producer of natural latex worldwide. Over 90%
of all patient examination gloves are made from natural latex, and it is
estimated that up to 80% of NRL patient examination gloves consumed in the
U.S. are manufactured in Malaysia (68). The
Association of Malaysian Medical Industries (AMMI) represents Malaysian
and multinational companies involved in the development and manufacture of
medical devices, products, equipment and services in Malaysia for the
health care community worldwide. The Malaysian Rubber Glove Manufacturers'
Association (MRGMA) specifically represents the NRL glove manufacturers.
According to the AMMI and MRGMA, any significant increase in the numbers
of medical gloves available for importation is not likely. However, a
shift in the types of gloves (powdered to powder-free) is already
occurring.
In June 1997 as a result of the NIOSH alert, five questions regarding
current and future availability of medical gloves to the U.S. were posed
to the entire 20 company AMMI membership, nine of which were glove-only
manufacturers, also members of MRGMA. The responses were compiled and
presented to CDRH by an AMMI executive and MRGMA member at a subsequent
June meeting. The questions and AMMI responses follow. Wherever
appropriate, supplemental supporting documentation is included.
The total capacity from Malaysia in 1996 was 13 billion (including 10% non-NRL) pieces. This capacity will not change significantly. The projected Malaysian industry trend is to shift the ratio of powdered (P) to powder-free (PF) natural rubber latex. AMMI and MRGMA project this shift to be rapid as indicated below.
P to PF Latex | |
12 months ago | 80:20 |
6 months ago | 75:25 |
today (June 1997) | 65:35 |
12 months from now | 50:50 |
The ratio of Malaysian medical gloves for U.S. distribution to the rest of the world is 70:30. Partly due to volume and purchasing requirements, other countries are more willing to pay the higher prices of powder-free NRL gloves. As a comparison to the P to PF ratio above, the ratio in the United Kingdom is:
P to PF Latex | |
3 months ago | 75:25 |
today (June 1997) | 55:45 |
12 months from now | 40:60 |
If the U.S. health care community could bear the "current
market price" of gloves, the powder-free glove supply to other
parts of the world could be significantly shifted to the U.S. Demand
for powdered gloves has already dropped worldwide. One constraint to
any possible shift is long-term contracts. Half or 50% of glove
manufacturers have long-term contracts that stretch 6-12 months.
Unless the U.S. price warranted, these contracts would not be
re-negotiated.
The lines producing powder-free NRL gloves are currently working to
capacity. Conversion of lines is expensive and requires 12-18 months
before realizing an increased capacity. Some of the obstacles include
acquiring chlorinators, which are backlogged worldwide, and water
treatment enhancements. It is doubtful that the industrial process
would shift to greater than 60% powder-free vs. 40% powdered NRL. Any
greater erosion from powdered would be made up by a shift to non-NRL.
Ten percent of the current Malaysian market is non-NRL and is growing.
Although non-latex technology is not yet equal to that of natural
rubber latex, glove manufacturers are attempting to perfect the
nonlatex process and anticipate future increases in the nonlatex
market.
However, additional FDA staff research found that non-NRL gloves,
other than vinyl, are considerably more expensive than NRL gloves.
|
||||
Powdered | ||||
Powder-free | ||||
% of Increase for Powder-free Product | |
For the powdered gloves, NRL costs are 11.4% higher than vinyl but
synthetic rubber is 128.5% higher than vinyl and 105% higher than NRL.
For powder-free gloves, NRL costs are 39% higher than vinyl but
synthetic rubber is 138% higher than vinyl and 72.4% higher than NRL.
Moving to a synthetic glove is currently cost prohibitive for U.S.
hospitals.
Although vinyl gloves are less expensive than NRL, research
indicates they are not necessarily the best alternative. Both NRL and
vinyl patient examination gloves provide protection against
microorganisms; however, it has been demonstrated that NRL is
preferred to vinyl for more effective and durable barrier qualities
(70, 71). NRL is pliable allowing for natural
molding for more appropriate fit and has the ability to reseal when
tiny punctures occur. In general, NRL provides comfort to the wearer,
adequately protects against microorganisms, and provides adequate
barrier effectiveness when used for medical and nursing procedures
(70). Consequently, NRL is still the barrier of
choice in the U.S.
U.S. entry requirements can be a problem for glove manufacturers
which result in delays and, in some cases, a barrier too costly to
pursue. Some specific obstacles which act as a deterrent are:
Barrier integrity is the main concern for medical gloves and glove
manufacturers. Producing a product that will consistently meet water
leak tests is of special concern. However, the current anxiety over
natural latex allergy is resulting in a shift to materials and/or
processes that may compromise barrier integrity. In a shortage
situation, or even a perceived shortage situation, inconsistent
quality suppliers may seize the opportunity to move into the U.S.
market. This will result in poor barrier products entering the U.S.,
much as they did in 1988-89 when demand rapidly increased because of
concern regarding universal precautions.
Producing a product that will have acceptable shelf life (one-year) is another special concern and/or difficulty. Powder-free technology is not easy and chlorination contributes to the difficulty. Most powder-free gloves are chlorinated and suppliers of auxiliary equipment are already back-ordered at least six months. However, chlorination is not the only process for producing powder-free NRL gloves. More emphasis needs to be placed on other processes which may help improve shelf life.
In summary and based on additional investigation, comprehensive
labeling, including warnings and precautions, added to all medical NRL
gloves would not be significant. The health care community is largely
aware of natural latex allergenicity and has been making appropriate
adjustments. The demand for more powder-free or lower protein gloves
will most likely increase, and as refinement in other manufacturing
processes improve and lower protein NRL is developed, the shift will
be toward medical gloves other than chlorinated powder-free.
Author: Carol Herman
References
CDRH Glove Powder Working Group:
Terrell Cunninghan | CDRH | ODE |
Sharon Dillard | CDRH | OSB |
John Farnham | CDRH | OC |
Carol Herman | CDRH | OSB |
Delon Hull | NIOSH | |
Ron Kaczmarek | CDRH | OSB |
Chiu Lin | CDRH | ODE |
Andrew Lowery | CDRH | OHIP |
Katharine Merritt | CDRH | OST |
John Stigi | CDRH | OHIP |
Mel Stratmeyer | CDRH | OST |
Vesna Tomazic | CDRH | OST |
Donna Walsh | CDRH | OST |
(Updated January 7, 1998)
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