Glutaraldehyde Exposure Observing and Control as a Cold Sterilization Solution Essay

Summary

The solution glutaraldehyde has adverse side effects on employees who work with it that need to be checked. Although it is very handy as a sterilizer in the health care industry, glutaraldehyde exposure levels need to be regulated to decrease risks facing workers. By assessing the samples of air collected from within the workplace where glutaraldehyde is frequently used, levels of exposure that were recorded reveal that the levels are high thus the need for less exposure levels. Additional research methods ought to be carried out to attain more reliable methods of air sample collection to verify the levels of exposure to glutaraldehyde.

Foreword

The chemical solution (C₅H₈O₂) has diverse industrial purposes globally. In Australia, among many examples of uses of glutaraldehyde include its use in x-ray film dispensation as a solidifier, in histochemistry as a tissue adhesive and in the industry of health care as a cold disinfectant. It may also work in the treatment of water as a biocide, as a solution for sanitation in transferable restrooms and airplanes, aquaculture; as well as a chemical additive in oils; and a fixative in leather processing. As useful as glutaraldehyde may be, exposure to it, as has been reported, leads to health problems (Reese, 2003, p497). This raises the concern, as Erickson observed on “control measures and monitoring of exposure to glutaraldehyde so as to avoid health problems that are resultant of exposure to glutaraldehyde (Erickson, 1996, p 187). This paper will talk about glutaraldehyde and the health tribulations experienced by workers in health care whilst working with this solution in the course of disinfection of apparatus. The paper will go on to elucidate on the average exposure and methods of sampling that can be carried out to check exposure to glutaraldehyde at the workplace. It will conclude with measures of control required to guarantee safe exposure levels for personnel.

The chemical solution glutaraldehyde

The solution glutaraldehyde (1, 5-glutaral or pentanedione) CAS number 111-30-8, is a dialdehyde which exhibits a prospective for sporicidal, fungicidal, virudical, mycobactericidal and bactericidal actions. Glutaraldehyde is found majorly in aqueous solution and is an oily colorless fluid with levels of concentration that range from 50% w/w to less than 1% w/w (Finucane, 2006, p295). Because of its highly volatile characteristics, it is classified as a dangerous solution of which a considerable concentration that is airborne can be created at room temperature in some situations.

Glutaraldehyde was brought into the health care industry in the early 1960’s and was used as an implement disinfectant. 55% of Australia utilizes glutaraldehyde as a cold disinfectant. It is one of the main end- uses of the solution for medical paraphernalia that is susceptible to heat and cannot be uncontaminated by autoclave, including appliances with lenses that require high-level disinfection amid patient use. Recommendations for its use come very high, as it is now the sole effectual agent against HIV.

Glutaraldehyde, as a decontaminator, is classified as an irritant as useful as it may be in the industry of health care. Harmful effects may therefore be encountered because of exposure to either vapor or the solution (Perkins, 1996, 121). Complaints have abounded on employees, about contracting dermatitis on their arms, hand’s and faces. Grievance’s from employee’s exposed to glutaraldehyde vapors and solutions range from respiratory, skin to eye irritations. A few workers experienced respiratory or skin sensitizations following exposure, whereas others experienced throat, nose, or chest tightness caused by respiratory exasperation from vapors of glutaraldehyde. Relatively, nausea, dizziness and headaches have also been reported as indicators of glutaraldehyde exposure. After preliminary exposure, effects may have dormancy interlude of a couple of years to a few weeks’ thus delayed or immediate effects. A hazard alert regarding glutaraldehyde usage was issued by Worksafe Australia predominantly for the health care industry. They suggested instantaneous upgrading in control procedures to minimize its exposure at the place of work. This was in October 1991. Optional substances may be used but regrettably, some are in any case more harmful. Besides, glutaraldehyde is mainly utilized because of its inability to corrode, lower cost, effectiveness, sterilizing speed and it is easy to use.

A person may be exposed to the substance through direct contact with the skin or inhaling. The most high-risk employees include the ones who work with directly sterilizing equipment like endoscopy, bronchoscopes nurses, surgery as well as assistants to dentists. They normally soak the apparatus in baths for some time then rinse them with water. The baths that are open may end in exposure to vapors. Exposure occurs when moving soak baths around or emptying them and when setting or removing apparatus. Disposing and pouring are when high levels of exposure are experienced. It is also during handling of the substance when cleaning instruments manually and altering as well as activating the solutions. When disposing the solution the process lasts not more than five minutes and is done by one individual at either the start or end of the week while during decantation, exposure lasts not more than six minutes. When cleaning apparatus manually, exposure lasts about four to five minutes and is done repeatedly every thirty minutes each time the instrument is removed or installed from the unit of cleaning. Indirect contact to glutaraldehyde may happen to employees who are in the same room in the event of the room being ventilated poorly.

Techniques of sample collection

For vicinity and individual sampling, air monitoring may be carried out. Vicinity /area sampling may be obtained above open tanks, atop automatic units for cleansing or around the point of head height whilst individual sampling may be obtained at the inhalation precinct of employees’. Area sampling should be done particularly as other employees are at the possibility of exposure by being in the same poorly ventilated room even though individual sampling is favoured. Sampling is obtained in the course of the climax of the workload time, here during discarding, preparing and loading and as the instruments are cleansed manually or as they are removed or placed in the baths.

While there are numerous modes suggested by NICNAS of testing for glutaraldehyde air sampling, NIOSH proposed the application of silica gel adsorption via OSHA technique 64 with the option of 2, 4-dinitrophenylhydrazine hydrochloride (DNPH) (Reese, 2006, 68). As for swift, simple sampling which non-professional people, may do, utilization of Glutaraldemeter for express- reading exposure is proposed by OSHA. Research has been done on inert diffusion badges and provided moderately acceptable outcomes though a few still think active sampling is more precise. To acquire a more consistent outcome, more research on these badges should be explored.

OSHA method 64 with DNPH – High Performance Liquid Chromatographic (HPLC)

OSHA 64 has been verified to illustrate suitable outcomes and is more regularly utilized in studies. Recorded first are the pressure, temperature in the room and humidity. This is so that all sample outcomes will be rectified to average pressure and temperature prior to sampling. Prior to evaluation, calibration ought to be carried out. A 37 mm sieve cassette is used as the sampler with DNPH pre-layered with strainers of glass fibre. A calibrated pump that has a flow rate of 1-2 L/minute is used to accumulate the sample (Stern, 1999, p793). 15 minutes is ample time to collect the samples then the filter cassettes may be sealed and preserved in a freezer until they are scrutinized and then sent to the laboratory for HPLC assessment. This is with the aid of an ultra violet sensor following sampling. Blank samples may also be incorporated.

Glutaraldemeter

This is a commercially accessible, direct reading device for checking glutaraldehyde in the air. The electrochemical fuel cell sensor that it has facilitates glutaraldehyde undertake catalytic oxidation forming electrical reactions comparative to the amount of glutaraldehyde in the air. The meter is fitted with a sample pump that in 60 seconds pulls in a 10 ml sample. Air sampling is gathered following calibration then sample tubes put at the pump. The gadget provides fast information for people to estimate exposure at the workstation, is uncomplicated and handy to utilize, and does not need expertise on sampling. Caution should be heeded as any interference from aldehydes and alcohols may provide erroneous outcomes even though the Glutaraldemeter may provide instant exposure readings. OSHA proposes conducting dynamic sampling as has more sensitivity and is consistent in contrast to Glutaraldemeter and inert sampling.

Gas Chromatographic Analysis/Silica Gel Adsorption

A glass tube holds two segments of silica gel which is encrusted with 2, 4 dinitrophenylhydrazine HCL (DNPH) and is fastened to a special sampling pump with a malleable tubing. This is how samples for this method are collected. Then crack the ends of the sampler and affix it to the personal sampling pump with the tube subsequent to regulating each sampling pump. For the overall sample size of 1-30 L, the pump rate of its flow ought to be between 0.05 and 0.5 L/min. Once sampling is done, seal the tubes instantaneously, stash in freezer pending analysis, and simultaneously with blanks, pack and dispatch to the laboratory for scrutiny of gas chromatographic. The accumulated glutaraldehyde is then desorbed from the tube with 1 ml of acetone -HPLC grade, and then computed via gas chromatography by way of flame-ionizing sensor. This procedure is fitting for exposure of 15 minutes.

Management of exposure to glutaraldehyde

To decrease the exposure of workers of glutaraldehyde to a secure level, as stated by DiBerardinis, “Apt control procedures ought to be introduced.” (DiBerardinis, 1999, p 847). Several procedures may be implemented to guarantee health care personnel and the environs are not vulnerable to the solution and the vapours in excess of 0.1 ppm:

• An optional, less harmful cold disinfectant ought to be used if possible.
• Exposure to vapour may be reduced by using semi or fully- automated devices for sterilizing though there is an increased danger of leakages and spillage in the use of the machine.
• In the course of disposal or decanting the solution, circumvent sprays and spills as well as contact with the skin. Caution ought to be observed while dealing with the solution.
• For reduced exposure in the processes of working with baths, disposing, pouring or cleaning apparatus manually, a sufficient ventilation system ought to be in place.
• To decrease the figure of people exposed to glutaraldehyde, procedures with the solution ought to be secluded from common work regions.
• Employees exposed to the substance ought to be provided with ample information and coaching.
• Cautiously, and appropriately sanitize any leakage or spillage instantaneously.
• Apparatus ought to be rinsed in running water as nearly as can be done and either removed or put tenderly so as not to splatter or splash.
• Highly proposed with apt exit points are baths that are enclosed and with unyielding covers.
• Decreasing the level of exposure to 0.01 ppm or lower subsequent to blending for five minutes also counterbalances the chemical prior to disposal.
• Dressing appropriately in protecting gear e.g.:
  • Ample shoes that in instances of spillages or splashes may prevent skin contact.
  • To protect the body, a laboratory coat or synthetic apron should be worn.
  • Rather than protective safety glasses, shields for the face to protect from exposure are more effective.
  • For the arms, lengthy butyl rubber gloves or nitrile that may be utilized again are appropriate.
  • Oxygen masks, full or half-face that have vapour sieves that are organic and are approved by NIOSH and may be compatible with glutaraldehyde use.

Acceptable levels of exposure

There are diverse glutaraldehyde occupational exposure limits that vary in countries. Finucane stated that United Kingdom advocates the STEL (15 minutes) to 0.05 ppm which is a reduction from 0.2 ppm before 1999 while United States proposes the TLV top limit concentration of glutaraldehyde exposure at 0.05 ppm (Finucane, 2006, p388). OEL’s are steeper in other countries although the highest levels permitted are 0.2 ppm. NOHSC in Australia advises TWA of exposure not to exceed 0.1 ppm. In conformity, the Health Department of NSW too, has adjusted their exposure average to health care workers with peak levels of not more than 0.1 ppm as the contemporary Worksafe Exposure Standard. Set exposure for glutaraldehyde is 0.2 ppm, i.e. peak limitation, nationally (Perkins, 1996, 144).

NOHSC advocates for 0.1 ppm for TWA as a pointer for safe levels of exposure to glutaraldehyde in conforming to the laws of Australia. Employees who are exposed to glutaraldehyde for a short time daily should however be considered, unlike the ones exposed to the solution for an entire shift (Jeyaratnam, 1996, p 385). Presumably, exposure-sampling results via TWA standards may reveal that it is below safe limits. The NSW pointers for health employees are much more apt and are set at a maximum level of 0.1 ppm. Nonetheless, it is recommended to maintain exposure levels as low as possible (Tranter, 2004, 106). There is no proposal on doing skin exposure evaluation even as glutaraldehyde way in may also be via direct contact with the skin. On whether superfluous exposure may be acquired via dermal exposure, additional research ought to be conducted.

Recommendations

Glutaraldehyde may be advantageous to the industry of health care as a cold sterilizer but still its undesirable effects on health ought to be taken into consideration. To check the levels of exposure at workstations, evaluation of samples of air is necessary. Gardiner was of the opinion that health related predicaments could be drastically diminished to secure levels of 0.1 ppm with the implementation of suitable procedures of control (Gardiner, 2005, p 448). Outcomes on inert badges that are accessible are still taken as debatable. Research on whether extra exposure may occur because of straight contact with the skin in comparison to inhalation, ought to be carried out. Silica gel adsorption, Glutaraldemeter or OSHA method 64 may be used as monitoring methods for exposure to glutaraldehyde (Reese, 2006, p824).

Conclusion

In a synopsis, it can be stated that even if the Glutaraldemeter direct reading may be expedient, dynamic sampling is still favoured for exact outcomes. This is until more studies are carried out on how dependable direct-reading implements as well as passive badges may be relative to exposure of glutaraldehyde.

References

DiBerardinis, L. J. (1999). Handbook of occupational safety and health. New Jersey: Wiley.

Erickson, P. A. (1996). Occupational health and safety. Amsterdam: Elsevier.

Finucane, E. W. (2006). Definitions, convertions and calculations for occupational safety and health professionals. London: CRC/Taylor & Francis.

Gardiner, K., Harrington J.M. (2005). Occupational hygiene. New Jersey: Wiley-Blackwell.

Jeyaratnam, J. (1996). Textbook of occupational medicine practice. California: World Scientific.

Perkins, J. L. (1996). Modern industrial hygiene: Recognition and evaluation of chemical agents. New York. Van Nostrand Reinhold.

Reese, C. D. (2003). Occupational health and safety management: A practical approach. London: CRC/Taylor& Francis.

Reese, J. D. (2006). Handbook of OSHA construction safety and health. London: CRC/Taylor & Francis.

Stern, M. B. (1999). Applications and computational elements of industrial hygiene. Florida: Lewis Publishers.

Tranter, M. (2004). Occupational hygiene and risk assessment. Sydney. Allen and Unwin.