Occupational hazard in hospital staff exposed to 2 per cent glutaraldehyde in an endoscopy unit

Exposure frequency, intensity, and duration: What we know about work-related asthma risks for healthcare workers from cleaning and disinfection

The objective of this review was to scope the current evidence base related to three exposure assessment concepts: frequency, intensity, and duration (latency) for cleaning and disinfection exposures in healthcare and subsequent work-related asthma risks. A search strategy was developed addressing intersections of four main concepts: (1) work-related asthma; (2) occupation (healthcare workers/nurses); (3) cleaning and disinfection; and (4) exposure. Three databases were searched: Embase, PubMed, and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) database. Data were extracted related to three main components of risk assessment: (1) exposure frequency, (2) exposure intensity, and (3) exposure duration. Latency data were analyzed using an exponential distribution fit, and extracted concentration data were compared to occupational exposure limits. The final number of included sources from which data were extracted was 133. Latency periods for occupational asthma were exponentially distributed, with a mean waiting time (1/λ) of 4.55 years. No extracted concentration data were above OELs except for some formaldehyde and glutaraldehyde concentrations. Data from included sources also indicated some evidence for a dose-response relationship regarding increased frequency yielding increased risk, but this relationship is unclear due to potential confounders (differences in role/task and associated exposure) and the healthy worker effect. Data priority needs to include linking concentration data to health outcomes, as most current literature does not include both types of measurements in a single study, leading to uncertainty in dose-response relationships.

Identifying a reference list of respiratory sensitizers for the evaluation of novel approaches to study respiratory sensitization

The induction of immunological responses that trigger bio-physiological symptoms in the respiratory tract following repeated exposure to a substance, is known as respiratory sensitization. The inducing compound is known as a respiratory sensitizer. While respiratory sensitization by high molecular weight (HMW) materials is recognized and extensively studied, much less information is available regarding low molecular weight (LMW) materials as respiratory sensitizers. Variability of symptoms presented in humans from such exposures, limited availability of (and access to) documented reports, and the absence of standardized and validated test models, hinders the identification of true respiratory sensitizers. This review aims to sort suspected LMW respiratory sensitizers based on available compelling, reasonable, inadequate, or questionable evidence in humans from occupational exposures and use this information to compose a reference list of reported chemical respiratory sensitizers for scientific research purposes. A list of 97 reported respiratory sensitizers was generated from six sources, and 52 LMW organic chemicals were identified, reviewed, and assigned to the four evidence categories. Less than 10 chemicals were confirmed with compelling evidence for induction of respiratory sensitization in humans from occupational exposures. Here, we propose the reference list for developing novel research on respiratory sensitization.

Corrosive Esophagitis and Gastritis Induced by Glutaraldehyde Ingestion

Corrosive esophagitis and gastritis are characterized by caustic damage due to ingestion of chemical agents. Caustic agents cause tissue destruction through liquefaction or coagulation reactions. Here, we report a case of corrosive esophagitis and gastritis caused by accidental ingestion of glutaraldehyde in Korea. A 62-year-old man presented to the emergency department 8 hours after ingesting glutaraldehyde, which is widely used for the prevention of foot-and-mouth disease in pigs. Urgent endoscopic examination revealed severely damaged mucosae of the esophagus and stomach. With conservative treatment, the patient’s condition was improved, and he was discharged on the 35th day of admission.

Final Report on the Safety Assessment of Glutaral

The dialdehyde Glutaral (also commonly called glutaraldehyde) is used in a wide variety of cosmetics as a preservative. In vitro dermal penetration studies of Glutaral indicate low penetration through animal skin and even less through human skin. The oral LD50 of Glutaral for rats ranged from 66 mg/kg up to 733 mg/kg. A 28-day dermal toxicity study of Glutaral produced skin irritation and slight effects on weight and blood chemistry with concentrations as low as 50 mg/kg/day. Animal skin irritation was dose-dependant, with a no-effect concentration of 1%. Ocular exposure to Glutaral caused severe irritation in rabbits at concentrations 1%, with a no-effect level of 0.1%. Glutaral was not embryotoxic, fetotoxic, or teratogenic at concentrations that did not cause severe maternal toxicity. The no observable adverse effects level for reproduction toxicity was > 1,000 ppm. Bacterial mutagenesis tests produced mixed results, as would be expected for a preservative. In most mammalian system mutagenesis tests, Glutaral was not genotoxic. In a 2-year drinking water study in rats, there was an increase in large granular lymphocytic leukemia (LGLL), but only in females administered 50–1,000 ppm Glutaral. The response was not dose dependent. Clinical studies report some evidence of dermal irritation and sensitization, but no photosensitization. Occupational data and animal studies indicate that inhalation of Glutaral can cause respiratory irritation, in addition to skin effects. Evaluation of the increased incidence of LGLL in the 2-year drinking water study indicated that the incidence was within the historical control levels for this spontaneously occurring neoplasm. These data, however, were not considered sufficient to base a finding of safety of Glutaral in products intended for prolonged use. It was concluded that a 2-year dermal carcinogenicity study following National Toxicology Program (NTP) procedures was needed to complete the safety assessment of Glutaral for use in leave-on products. For rinse-off products, it was concluded that the ocular and dermal irritancy of Glutaral could be substantially avoided if the concentration did not exceed 0.5% and exposure was only brief and discontinuous. Because it can cause respiratory irritation, it was concluded that Glutaral should not be used in aerosolized cosmetic products.

The alterations in neurotransmitters and their metabolites in discrete brain regions in the rats after inhalation of disinfectant, glutaraldehyde or ortho-phthalaldehyde for 4 weeks

Glutaraldehyde (GA) and ortho-phtalaldehyde (OPA) have been widely used as major components of disinfectants in hospitals. We evaluated the alterations in GA or OPA in rats after subacute inhalation exposure by determining levels of neurotransmitters (norepinephrine [NE], dopamine [DA], DA metabolites, dihydroxyphenylacetic acid [DOPAC] and homovanillic acid [HVA], indoleamine serotonin [5-HT] and 5-HT metabolite, 5-hydroxyindoleacetic acid [5-HIAA]) in discrete brain regions using high performance liquid chromatography (HPLC) equipped with an electrochemical detector. Female Wistar rats were exposed to 0, 50, 100, or 200 ppb gaseous GA or OPA by inhalation for 1 h per day, 5 d per week for 4 wk. Following the exposure, the brain of each rat was removed and dissected into cerebrum, cerebellum, medulla oblongata, midbrain, corpus striatum and hypothalamus. The neurotransmitters and their metabolites were extracted from each brain region, and determined by HPLC. Regarding GA, the daily water intake of the 50 or the 200 ppb exposed groups was significantly lower than that of the control. DA and 5-HIAA levels in the medulla oblongata among the GA exposed groups were significantly lower than those of the control. For OPA, the mean final body weight and daily food intake of the 100 or 200 ppb exposed groups were significantly lower than those of the control. The mean DA concentrations in the cerebrum in the groups exposed to OPA were significantly lower than those of the control. OPA may modulate DA metabolism in the cerebrum of female rats. The levels GA or OPA that induced alienations in neurotransmitters were comparable to those levels usually found in hospitals, further studies are warranted to evaluate the of safety of disinfectants containing GA or OPA.

Potential allergy and irritation incidents among health care workers

This study describes the types, causes, and outcomes of potential irritation and allergy incidents among workers in British Columbia's health care industry. Data on occupation-induced allergy and irritation incidents were extracted from a standardized database using the number of productive hours obtained from payroll data as a denominator during a 1-year period from three British Columbia health regions. Younger workers, female workers, facility support service workers, laboratory assistants and technicians, and maintenance and acute care workers were found to be at higher risk for allergy and irritation incidents. Major causes of allergy and irritation incidents included chemicals, blood and body fluids, food and objects, communicable diseases, air quality, and latex. A larger proportion of chemically induced incidents resulted in first aid care only, whereas non-chemical incidents required more emergency room visits.

Glutaraldehyde exposures among workers making bioprosthetic heart valves

Exposure to glutaraldehyde is a recognized cause of work-related asthma. An investigation was undertaken to describe exposure to glutaraldehyde among workers making bioprosthetic heart valves and to make recommendations for prevention. At the two largest heart valve manufacturing facilities in California, the work process was observed; employer representatives and glutaraldehyde-exposed workers were interviewed; and employer written records, including company-generated industrial hygiene data, were analyzed. Approximately 600 female workers had continuous airborne exposure to glutaraldehyde over the course of every work shift and the routine potential for skin and eye contact with glutaraldehyde while making heart valves. Employee short-term (15-min) glutaraldehyde exposures were all well below the current regulatory ceiling level (0.20 ppm). Overall, approximately 40% of the glutaraldehyde-related job tasks involved exposures above the American Conference of Industrial Hygienists threshold limit value ceiling of 0.05 ppm; the majority (71.4% and 83.3%, depending on the company) involved exposures greater than 0.015 ppm. At one company, two cases of physician-diagnosed asthma were recorded by the employer in the previous 5-year period; these reports met the surveillance case definition for new-onset, work-related asthma associated with a known asthma inducer. Factors that contributed to worker exposure included large exposed surface areas of glutaraldehyde under agitation; working with glutaraldehyde-treated tissue in proximity to workers' breathing zones; manual pouring and disposal of glutaraldehyde solutions without local exhaust ventilation, eye protection, and waste neutralization; and prolonged use of latex gloves. Workers making bioprosthetic heart valves are at risk for occupationally acquired asthma. Employers should implement additional engineering controls to minimize workers' exposures to at least below a level of 0.015 ppm, an appropriate glove to prevent workers' skin exposure to glutaraldehyde, consistent and universal use of eye protection, and a medical surveillance program for glutaraldehyde-exposed workers.

[Occupational health of endoscope sterilization workers in medical institutions in Osaka Prefecture]

To clarify the actual condition of endoscope sterilization work and the adverse health effects of disinfectants on personnel, a questionnaire was sent to 173 medical institutions in Osaka Prefecture. Glutaraldehyde (GA), ortho-phtalaldehyde (OPA), and hyperacetic acid were used as disinfectants of endoscopes by 55.5%, 32.4%, and 8.7% of the medical institutions respectively. The kind of disinfectant used had been changed in 57.8% of these institutions during the past five years, and it was confirmed that the use of substitutes for GA, such as OPA and hyperacetic acid, has increased. Personnel in 35.8% of the institutions complained about symptoms during sterilization work. The kind of disinfectant being used when they complained was GA in many cases and OPA in others. A general ventilation system has now been installed in 72.3% of the institutions; local exhaust systems have been installed in fewer, only 23.4%. Protective gloves were used at about half of the institutions, but protective masks and glasses were seldom used. This study shows that the occupational health problems of endoscope sterilization work have not been resolved. Consequently, it is necessary to promote the installation of ventilation systems and the use of protective devices in all institutions. Health education in regard to the handling of disinfectants is also necessary. Because little information is available about the toxic effects of OPA and hyperacetic acid, epidemiological studies must be conducted to clarify the human health effect of these disinfectants.

Chemical occupational risks identified by nurses in a hospital environment

Hospital nursing workers are exposed to occupational chemical risks. This quantitative study aimed to identify what chemical substances nurses have contact with in their activities, what substances cause health problems and what alterations correspond to possible problems caused by the chemical products they mention. A self-administered data collection instrument was answered by 53 nurses, who mentioned exposure mainly to antibiotics and benzene (100%), iodine (98.1%) and latex-talc (88.7%); the main problem-causing substances mentioned were antineoplastic substances (86.7%), glutaraldehyde (79.2%) and ethylene oxide (75.5%); the described health alterations were: eye watering; allergic reactions; nausea and vomiting, while other health problems that can be caused by the above listed products were not mentioned. These workers need further information on occupational chemical risks, which they could have received in undergraduate or permanent education courses.

Respiratory health survey of respiratory therapists

STUDY OBJECTIVES

The purpose of this study was to determine whether respiratory therapists (RTs) had an elevated risk of respiratory symptoms and to determine the association of work exposures with symptoms.

METHODS

Mailed questionnaire responses from 275 RTs working in British Columbia, Canada, were compared to those of 628 physiotherapists who had been surveyed previously. Analyses incorporated logistic regression analysis with adjustment for age, sex, smoking status, and childhood asthma.

RESULTS

Compared to physiotherapists, RTs had over twice the risk of being woken by dyspnea, having wheeze, asthma attacks, and asthma diagnosed after entering the profession. Among RTs, two work factors associated with asthma were sterilizing instruments with glutaraldehyde-based solutions and the use of aerosolized ribavirin. RTs who used an oxygen tent or hood had the highest risk of asthma diagnosed after entering the profession (odds ratio [OR], 8.3; 95% confidence interval [CI], 12.6 to 26.0) and of asthma attacks in the last 12 months (OR, 3.6; 95% CI, 1.2 to 10.9).

CONCLUSIONS

Our data suggest that RTs may be at an increased risk for asthma-like symptoms and for receiving a diagnosis of asthma since starting to work in their profession, possibly related to exposure to glutaraldehyde and aerosolized ribavirin.

A Prospective Comparison Between Stabilized Glutaraldehyde and Chlorhexidine Gluconate for Preoperative Skin Antisepsis in Dogs

OBJECTIVE

To compare the efficacy of 0.3% stabilized glutaraldehyde and alcohol (SG+A), 0.3% SG and water (SG+W), and 4% chlorhexidine gluconate tincture (CG+A), as skin disinfectants in dogs undergoing ovariohysterectomy.

STUDY DESIGN

Prospective, blinded clinical study.

ANIMALS

One hundred and twenty-one dogs.

METHODS

Cutaneous bacterial colony forming units (CFU) from the perioperative site after skin preparation, after antisepsis, and after surgery (incisional and paramedian), were quantified. The influence of high initial bacterial counts (> or =150 CFU) and surgical time on antibacterial efficacy was examined and the proportion of dogs from which Staphylococcus intermedius was cultured, determined. Perioperative skin reactions and wound infections were documented.

RESULTS

All 3 antiseptic solutions significantly and equally reduced CFU to all post-antisepsis sampling levels irrespective of surgical duration (mean surgical times 151.6, 136.2, and 149.6 minutes for CG+A, SG+A and SG+W, respectively). Median percentage reductions in CFU ranged between 99.3% and 100%. In dogs with initial high counts and disinfected with CG+A and SG+W, the incisional samples had significantly higher counts than the post-antisepsis samples. In the CG+A and SG+W groups, the proportion of post-surgery samples yielding S. intermedius was significantly higher at the incisional than the paramedian sites. Eight mild cutaneous reactions were recorded in equal proportions for the 3 solutions. There were no recorded infections.

CONCLUSIONS

All 3 preparations had an equal ability to reduce and maintain low CFU counts, with minimal cutaneous reactions.

CLINICAL RELEVANCE

SG solutions are safe and effective preoperative skin antiseptics for elective clean-contaminated surgical procedures.

Riscos químicos a que estão submetidos os trabalhadores de enfermagem: uma revisão de literatura

O estudo consiste em levantamento bibliográfico nas bases de dados LILACS, MEDLINE e ILO-CIS BULLETIN - SAFETY AND HEALTH AT WORK sobre a temática riscos ocupacionais químicos, tendo como objetivo identificar, nas publicações encontradas, os principais agentes que podem favorecer o contato com esses riscos e provocar alterações de saúde nos trabalhadores de enfermagem. Foram encontrados 37 artigos, sendo apenas quatro publicados em periódicos nacionais que relatavam a detecção dos riscos químicos na manipulação de drogas citostáticas, na exposição a gases anestésicos, vapores de formaldeído/glutaraldeído e a gases esterilizantes, entre outros.

In-use evaluation of Perasafe compared with Cidex in fibreoptic bronchoscope disinfection

The mycobactericidal activity of Perasafe (0.26% peracetic acid) was compared with that of Cidex (2% alkaline glutaraldehyde) by an in-use test. Fibreoptic bronchoscopes were artificially contaminated with Mycobacterium tuberculosis or Mycobacterium avium-intracellulare in sputum and, after manual pre-cleaning with a neutral soap, 10 and 20 min disinfection periods were tested. Perasafe was as effective as Cidex, thus requiring a 10 min disinfection period against M. tuberculosis and 20 min against M. avium-intracellulare. The results demonstrate that Perasafe is an effective disinfectant for use in reprocessing fibreoptic bronchoscopes.

Symptoms and lung function in health care personnel exposed to glutaraldehyde

BACKGROUND

Glutaraldehyde is widely used as a disinfectant for endoscopic equipment. The aim of this study was to investigate work practices and glutaraldehyde exposure in relation to symptoms and lung function.

METHODS

A questionnaire was administered to 76 nurses. Exposed nurses (n = 38) also completed lung function tests and visual analogue scales before and after a work session in which glutaraldehyde exposure occurred. Disinfection activities were timed and counted, personal exposures established, and control measures documented.

RESULTS

Exposure values above the exposure limit (0.10 ppm) were found for all exposure control methods except for the enclosed washing machine. Skin symptoms were 3.6 times more likely to be reported by exposed workers. None of the other symptoms were significantly associated with glutaraldehyde exposure. There were significant cross-shift reductions in FVC and FEV(1) in the exposed group. No evidence of a dose-response relationship for symptoms or lung function was found.

CONCLUSIONS

Further exposure controls for both glutaraldehyde and gloves are required to improve skin care in glutaraldehyde exposed nurses. Exposure monitoring methods also need review.

Comparison of a solution of super-oxidized water (Sterilox) with glutaraldehyde for the disinfection of bronchoscopes, contaminated

The efficacy of Sterilox, a super-oxidized water holding a reduction/oxidation potential of greater than 950 mV was compared with the efficacy of glutaraldehyde against clinical isolates of Mycobacterium tuberculosis and Mycobacterium avium-intracellulare. An in use method using an automated bronchoscope washing machine demonstrated that over five cycles, Sterilox with a contact time of 5 min gave log10 reduction factors for M. tuberculosis and M. avium-intracellulare of >6 and >5, respectively. Glutaraldehyde with a contact time of 10 min gave log10 reduction factors for both M. tuberculosis and M. avium-intracellulare of >4, and at a contact time of 20 min >5 each. The non-toxic nature of Sterilox, together with the reduction in viable counts demonstrated in this study, suggest that the solution is an effective alternative mycobactericidal agent to the established disinfectants for the disinfection of bronchoscopes and, therefore, justifies further investigation.

Properties of an enzyme-based low-level iodine disinfectant

An enzyme-based iodine (EBI) disinfectant that continuously generates free molecular iodine in a controlled fashion was developed and evaluated for use in disinfecting flexible fibreoptic endoscopes (FFEs). EBI is a powder concentrate that produces iodine from sodium iodide and calcium peroxide when catalyzed by horseradish peroxidase. After dissolution in water, it delivers relatively high concentrations of free molecular iodine (> 15 ppm) at relatively low concentrations of total iodine (30-40 ppm). It demonstrates the ability to function as an effective low level iodine disinfectant by rapidly inactivating bacteria, fungi and viruses. A unique feature of the EBI system is the ability to reoxidize reduced iodine which results in a constant level of active (free molecular) iodine during use. EBI inactivates Mycobacterium bovis var BCG more rapidly than 2% glutaraldehyde (Cidex-7). Its sporicidal activity, however, was found to be slower than the aldehyde formulation. The qualification of EBI for use as a practical disinfectant was shown by its negligible toxicity in dermal, ocular, oral and inhalation studies on animals, which is attributed to the low level of total iodine in the solution.

Society of Gastroenterology Nurses and Associates, Inc. (SGNA) Endoscopic Disinfectant Survey results compared with control group

Disinfectant surveys from responding members of the American Society of Postanesthesia Nurses were divided into two groups based on whether or not they considered themselves to be exposed to disinfectants in their work environment. Their survey responses were then compared with those obtained previously from members of the Society of Gastroenterology Nurses and Associates, Inc., who were regularly exposed to 2% alkaline glutaraldehyde in the work setting. There were significant differences among the groups in the percentage of respondents who reported having headaches, eye irritations, respiratory problems, shortness of breath, rashes, memory loss, mood swings, and fatigue. These findings support the association of these complaints with 2% alkaline glutaraldehyde exposure. In contrast, there were no significant differences among the groups in the percentage of respondents who reported having asthma, rhinitis, chest pain, nausea, diarrhea, muscle/joint pain, visual disturbances, or dermatitis.

Clinical and immunologic evaluation of workers exposed to glutaraldehyde

We describe immunologic responses in subjects exposed to glutaraldehyde (GA) who were diagnosed as having occupational asthma, or who described work-related respiratory symptoms. A series of GA-modified proteins was characterized, and used to analyse sera from 20 GA-exposed workers and 21 unexposed workers for IgE antibodies. Inhibition studies were used to determine the specificity of binding. The reaction of GA with albumin in different molar ratios produced a range of modified proteins, which were used to measure specific IgE antibodies. A significant difference between exposed and unexposed subjects with serum IgE less than 150 kU/l could be detected for GA-specific IgE antibodies (P - 0.026), and 31% of exposed workers with occupational asthma had antibody levels greater than the unexposed population (mean +2.5 SD). False-positive results were obtained with serum from unexposed workers who had total IgE levels greater than 150 kU/l, but this binding was not inhibited by GA-modified proteins. We report the first evidence of immunologic sensitization in some workers exposed to GA. However, GA may behave like many other low-molecular-weight chemicals in that specific antibodies can be detected in only a small percentage of exposed workers who report work-related respiratory symptoms.

Work related respiratory symptoms in radiographers

OBJECTIVE

To determine the prevalence of work related symptoms among radiographers compared with a control group of physiotherapists.

METHOD

A postal questionnaire was used to collect information from radiographers and physiotherapists who registered in the United Kingdom during 1985-9.

RESULTS

Satisfactory questionnaires were returned by 2354 (65%) of the radiographers and 3048 (69%) of the physiotherapists. There was a clear excess of work related symptoms among the radiographers. In particular, they were more likely to complain of symptoms that were worse at work, mouth soreness, sore, itchy, or runny eyes, persistent blocked nose, persistent itchy nose or sneezing, sore throat, headache, and of lower respiratory tract symptoms, which were also worse on workdays. These symptoms were associated particularly with the use of automatic processing machines. 235 radiographers gave a history of wheeze or chest tightness that had been worse at work or on days when at work.

CONCLUSIONS

Work related symptoms suggesting irritation of the eyes and upper airways were more common in radiographers than controls, and may be related to exposure to x ray film processing chemicals. Men and women who reported work related wheeze or chest tightness will be followed up in more detail to assess the prevalence of occupational asthma in the cohort.

Respiratory peripheral sensory irritation and hypersensitivity studies with glutaraldehyde vapor

Overexposure to glutaraldehyde (GA) vapor (CAS No. 111-30-8) is known to cause peripheral sensory irritant effects in humans. Respiratory sensory irritation was investigated in male ND4 Swiss Webster mice to quantify the effect, and also as a preliminary to a study of the respiratory sensitizing potential of GA. For the irritation study, groups of four mice were exposed to seven different GA vapor concentrations in the range of 1.6 to 36.7 ppm, while respiratory rate (RR) was measured by plethysmography. Concentration-related decreases in RR were measured, with a maximum decrease at 3 to 20 min, which was sustained, indicating an absence of desensitization. The 50% decrease in RR (RD50) was calculated to be 13.9 ppm, which accords with the known sensory irritancy of GA and other aliphatic aldehydes. In a separate study, the respiratory sensitizing potential of GA vapor was studied in male Hartley guinea pigs, who were exposed for one hour per day for five consecutive days to an inducing GA vapor concentration of 13.9 ppm. Subsequent challenge exposures to 4.4 ppm at 14, 21, and 35 days after the final induction exposure did not produce any evidence of respiratory sensitization. The above findings confirm that GA vapor is a moderately potent peripheral sensory irritant, and does not produce respiratory sensitization in the guinea pig at the concentrations tested.

The efficacy of the disinfection of bronchoscopes contaminated in vitro with Mycobacterium tuberculosis and Mycobacterium avium-intracellulare in sputum: a comparison of Sactimed-I-Sinald and glutaraldehyde

The efficacy of Sactimed-I-Sinald and glutaraldehyde was tested against clinical isolates of Mycobacterium tuberculosis (MTB) and Mycobacterium avium-intracellulare (MAI). An in-use method demonstrated that over 10 disinfection cycles, using an auto-disinfector and a contact time of 60 min, MTB was eradicated in 10 out of 10 cycles with Sactimed-I-Sinald and five out of 10 cycles for glutaraldehyde. For MAI, Sactimed-I-Sinald showed a 5 log reduction at a 60 min contact time, which was not seen with glutaraldehyde. Although further evaluation is necessary, Sactimed-I-Sinald appears a promising alternative to glutaraldehyde.

Occupational asthma due to glutaraldehyde and formaldehyde in endoscopy and x ray departments

BACKGROUND

Glutaraldehyde is the best disinfectant for fibreoptic endoscopes. It is also used in the processing of x ray films. A number of studies have reported eye, nose, and respiratory symptoms in exposed workers. Three individual case reports of occupational asthma in endoscopy workers and a radiographer have also been published. We describe a further seven cases of occupational asthma due to glutaraldehyde in endoscopy and x ray departments, together with exposure levels measured during the challenge tests and in 19 endoscopy and x ray departments in the region.

METHODS

Eight workers were referred for investigation of suspected occupational asthma following direct or indirect exposure to glutaraldehyde at work. They were investigated by serial measurements of peak expiratory flow (PEF) and specific bronchial provocation tests. Glutaraldehyde levels were measured using personal and static short and longer term air samples during the challenge tests and in 13 endoscopy units and six x ray darkrooms in the region where concern about glutaraldehyde exposure had been expressed. Three of the workers investigated with occupational asthma came from departments where glutaraldehyde air measurements had been made; the others came from other hospitals or departments.

RESULTS

The diagnosis of occupational asthma was confirmed in seven workers, all of whom had PEF records suggestive of occupational asthma and positive specific bronchial challenge tests to glutaraldehyde. Bronchial provocation testing was negative in one worker who was no longer exposed and who had a less clearcut history of occupational asthma. Three workers also had a positive specific bronchial challenge to formaldehyde. The mean level of glutaraldehyde in air during the challenge tests was 0.068 mg/m3, about one tenth of the short term occupational exposure standard of 0.7 mg/m3. The levels obtained in the challenge chamber were similar to those measured in 13 endoscopy suites and six x ray darkrooms where median short term levels were 0.16 mg/m3 during decantation in endoscopy suites and < 0.009 mg/m3 in darkrooms.

CONCLUSIONS

Glutaraldehyde can cause occupational asthma. The exposure levels measured in the workplace suggest that sensitisation may occur at levels below the current occupational exposure standard.

Ocular and nasal irritation in operatives in Lancashire cotton and synthetic fibre mills

OBJECTIVES

To document the prevalence of work related ocular (eyeWRI) and nasal (noseWRI) irritation in workers in spinning mills of cotton and synthetic textile fibres and to relate the prevalence of symptoms to atopy, byssinotic symptoms, work history, and measured dust concentrations in the personal breathing zone and work area.

METHODS

A cross sectional study of 1048 cotton workers and 404 synthetic fibre workers was performed. A respiratory questionnaire was given to 1452 workers (95% of the total available population). Atopy was judged by skin prick tests to three common allergens. Work area cotton dust sampling (WAdust) was carried out according to EH25 guidelines in nine of the 11 spinning mills included in the study. Personal breathing zone dust concentrations were assessed with the IOM sampler to derive total dust exposure (PTdust) and a concentration calculated after the removal of fly (Pless).

RESULTS

3.7% of all operatives complained of symptoms of byssinosis, 253 (17.5%) complained of eyeWRI and 165 (11%) of noseWRI. These symptoms did not relate to atopy or byssinosis, or correlate univariately with any measure of cotton dust exposure (noseWRI v WAdust r = 0.153, PTdust r = 0.118, eyeWRI v WAdust r = 0.029, PTdust r = 0.052). Both of these symptoms on logistic regression analysis were related to being of white origin (P < 0.001), female sex (P < 0.001), and younger age (P < 0.001). With regression analysis, there was a negative relation between dust concentration and prevalence of symptoms.

CONCLUSION

Work related ocular and nasal irritation are the most common symptoms complained of by cotton textile workers. There was no relation between these symptoms and atopy, byssinosis, or dust concentration. It is likely that they relate to as yet unidentified agents unrelated to concentration of cotton dust.

Glutaraldehyde: current status and uses

Glutaraldehyde (pentanedial) is a dialdehyde that displays potent bactericidal, fungicidal, mycobactericidal, sporicidal, and virucidal activity. Pertinent to its activity is its interaction with amino groups in proteins and enzymes, but this simplistic statement masks the manner in which it inactivates various types of microorganisms. Notwithstanding its toxicity for medical staff, glutaraldehyde remains an invaluable compound for high-level disinfection purposes in endoscopy units.

Aldehyde disinfectants and health in endoscopy units. British Society of Gastroenterology Endoscopy Committee

Summary of main recommendations(1) Glutaraldehyde, used in most endoscopy units in the United Kingdom for the disinfection of flexible gastrointestinal endoscopes, is a toxic substance being an irritant and a sensitiser; symptoms associated with glutaraldehyde exposure are common among staff working in endoscopy units.(2) The Control of Substances Hazardous to Health Regulations 1988 (COSHH) obliges the employer to make a systematic assessment of risk to staff of exposure to glutaraldehyde and institute measures to deal effectively with exposure.(3) At present glutaraldehyde remains the first line agent for the disinfection of flexible gastrointestinal endoscopes. Other agents are being developed; a standard means of assessment for flexible endoscope disinfectants should be devised.(4) Equipment and accessories that are heat stable should be sterilised by autoclaving; disposable accessories should be used wherever possible.(5) Flexible gastrointestinal endoscopes should be disinfected within automated washer/disinfectors; trays, bowls or buckets for this purpose are unacceptable.(6) Local exhaust ventilation must be used to control glutaraldehyde vapour. Extracted air may be discharged direct to the atmosphere or passed over special absorbent filters and recirculated. Such control measures must be regularly tested and records retained.(7) Endoscope cleaning and disinfection should be carried out in a room dedicated to the purpose, equipped with control measures to maintain the concentration of glutaraldehyde vapour at a level certainly below the current occupational exposure standard of 0.2 ppm and preferably below the commonly used working limit of 0.1 ppm. Sites other than the endoscopy unit where endoscopy is regularly performed, such as the radiology department, should have their own fully equipped cleaning and disinfection room.(8) COSHH limits the use of personal protective equipment to those situations where other measures cannot adequately control exposure. Such equipment includes nitrile rubber gloves, apron, chemical grade eye protection, and respiratory protective equipment for organic vapours.(9) Monitoring of atmospheric levels of glutaraldehyde should be performed by a competent person such as an occupational hygienist; the currently preferred method of sampling uses a filtration technique, the commercially available meters being less reliable.(10) Health surveillance of staff is mandatory; occupational health records must be retained for 30 years.(11) Endoscopy staff must be informed of the risks of exposure to glutaraldehyde and trained in safe methods of its control. Only staff who have completed such an education and training programme should be allowed to disinfect endoscopes.(12) The unsafe use of glutaraldehyde has significant health and legal consequences; the safe use of glutaraldehyde may have revenue consequences that contribute significantly to the cost of gastrointestinal endoscopy.

An assessment of exposure to glutaraldehyde in hospitals: typical exposure levels and recommended control measures

An assessment of exposure to glutaraldehyde in cold sterilisation and x ray development processes was undertaken in 14 locations at six hospitals in south east England. The results obtained indicate that routine exposures of hospital workers to airborne concentrations of the compound are within the current United Kingdom occupational exposure limit of 0.7 mg m-3. There was the potential for skin contact in many of the activities observed and alternative sterilisation and disinfection procedures would have been more appropriate in some situations. Recommendations are made on reducing exposures as the current occupational exposure limit for this compound may not be appropriate.

Infection and endoscopy: who infects whom?

Infection is one of the major hazards of endoscopic procedures and is the commonest complication of endoscopic retrograde cholangio-pancreatography (ERCP) causing death. Prevention of endoscopy-associated infections is based on adequate cleaning and disinfection regimens. Scrupulous mechanical cleaning is fundamental; even prolonged chemical disinfection will be ineffective if cleaning has not been adequate. Special measures are required to prevent ERCP-related infections. It is important to recognize various special circumstances that increase a patient's susceptibility to infection and to administer antibiotic prophylaxis when appropriate.

A critical review of the toxicology of glutaraldehyde

Glutaraldehyde, a low molecular weight aldehyde, has been investigated for toxicity in humans and animals. Examination of this dialdehyde was indicated from previous studies with other aldehydes in which carcinogenicity of formaldehyde and toxicity of acetaldehyde and malonaldehyde have been disclosed. Information gaps concerning the actions of glutaraldehyde have been identified in this review and recommendations are suggested for additional short- and long-term studies. In particular, information regarding irritation of the respiratory tract, potential neurotoxicity, and developmental effects would assist in a complete hazard evaluation of glutaraldehyde. Further study related to disposition, metabolism, and reactions of glutaraldehyde may elucidate the mechanism of action.

Activity of glutaraldehyde at low concentrations (less than 2%) against poliovirus and its relevance to gastrointestinal endoscope disinfection procedures

The activity of glutaraldehyde (GTA) at low concentrations (less than 2%) against poliovirus was assessed by a suspension procedure. The inactivation kinetics showed that concentrations of less than or equal to 0.10% were effective against purified poliovirus at pH 7.2; a 1 log10 reduction was obtained in 70 min with 0.02% GTA, and a 3 log10 reduction was obtained in 30 min with 0.10% GTA. GTA activity at low concentrations was greatly enhanced at alkaline pH, but was completely abolished at acid pH. In contrast, the inactivation assays on poliovirus RNA showed that it was highly resistant to GTA at concentrations up to 1.0% at pH 7.2. At pH 8.3 a low inactivation was noticed with 1.0% GTA. Our results are of relevance to hospital practice in digestive endoscopy investigations because there has been an increasing tendency to use low concentrations of GTA and very short contact times in disinfection procedures.

AIDS: practising safe endoscopy

The emergence of HIV has provoked a widespread reappraisal of infection control practices in endoscopy units. Infection control practices should be applied to all patients alike without recourse to selection or screening. Although there has only been one reported instance of viral transmission at endoscopy, HIV could in theory be transmitted by a contaminated endoscope. Experience suggests that this is more likely to occur from damaged endoscopes, if an unsuitable disinfectant is used or endoscopes are not precleaned. In-use studies have shown that HIV contaminates endoscopes used on patients with AIDS, but in amounts too small to cause infection in tissue cultures. Cleaning in neutral detergent is extremely effective in removing contaminating micro-organisms, including HIV, from endoscopes. Aldehydes are the disinfectants of choice, but any disinfectant may fail if organic material is not removed by cleaning. After thorough cleaning, short disinfection times (e.g. four minutes) ensure inactivation of all relevant micro-organisms except Cryptosporidium and mycobacteria, although in practice even these organisms are likely to be reduced to non-pathogenic levels. Accidental needlestick injuries are the greatest hazard in the endoscopy suite; needles should not be resheathed and biopsy forceps must be handled with great care. The wearing of gloves should become second nature.