The harm of glutaraldehyde to humans

We often use various disinfectant products in our daily life. Although there are many types of disinfectants, the chemical products they use in common are fixed. Glutaraldehyde is a necessary chemical for various disinfectants. However, long-term use of this product will cause great damage to our body. It will not only irritate our skin and other external organs, but also cause chronic diseases such as rhinitis and asthma, which is extremely harmful.

Glutaraldehyde (/netbook/glutar/glutaraldehyde) is an irritant powdered chemical with a vapor pressure of 17 mmHg @20℃. Soluble in water, the solubility is about 100 mg/ml at 20℃. The vapor pressure of aqueous solutions varies with concentration. The higher the concentration, the greater the vapor pressure. For example, the vapor pressure of 50% glutaraldehyde aqueous solution is 0.0152 mmHg @20℃, while the vapor pressure of 2%

The value of glutaraldehyde aqueous solution is 0.0012 mmHg @20℃.

Aqueous glutaraldehyde is used in hygiene and is the main ingredient of many disinfectants. The following are some of the more well-known disinfectant trade names:

CIDEX KENNEL SAFE

PARVOVIRUCIDE MERICIDE

ASEP OMNICIDE

FORMULAH PARVOCIDE

GPC-8 STABLESAFE

TK10 CROMESSOL

TOTACIDE

The labels of these products may state the presence of glutaraldehyde and its concentration, but manufacturers may also develop new products that do not contain glutaraldehyde.

What venues will use it?

Disinfectants containing glutaraldehyde can be used in the sanitation management of animal environments, such as veterinary hospitals, dog and cat kennels, stables, zoos, aviaries, poultry and livestock pens, etc.

The concentration of glutaraldehyde aqueous solution used in medical institutions varies according to its purpose, such as: 5-10% solution is used to treat foot hyperhidrosis; 5% solution is used as a hemostatic agent; 4-6.5%

The solution is used as a tissue fixative, dental root canal treatment, and X-ray film developer to accelerate film hardening; and after "activation" (adjusting from slightly acidic to slightly alkaline, pH = 7.5-8.5)

A 2% aqueous solution can be used as a low-temperature disinfectant to disinfect medical devices that cannot be sterilized at high temperatures (such as endoscopes), or to disinfect devices that can be sterilized at high temperatures in order to save time.

There are many units of glutaraldehyde used in medical institutions, among which the endoscope unit is the one with the highest usage and frequency, and is used to disinfect medical equipment such as endoscopes.

How do medical institutions use it as a disinfectant?

The disinfection ability of glutaraldehyde aqueous solution is affected by glutaraldehyde concentration, disinfection time, temperature, pH value, virus or bacteria type and organic matter remaining on the instrument. 2% glutaraldehyde aqueous solution is a commonly used disinfectant, which must be "activated" before use to increase the disinfection speed and ability. The activated glutaraldehyde solution can be used for manual disinfection and automatic machine disinfection.

The manual disinfection method is that the operator soaks the medical instruments in a vessel or sink filled with glutaraldehyde solution. After a period of time, the instruments are taken out and rinsed with sterile water or wiped with alcohol to remove the residual glutaraldehyde.

Automatic disinfection uses different types of disinfection machines and sets the operating time for each cleaning and disinfection step. The cleaning and disinfection process is as follows: lift the lid and insert the instrument → clean with cleaning solution → wash with water → air treatment → inject disinfectant for disinfection and recovery → air treatment → wash with water → open the lid and inject alcohol → air treatment → lift the lid and take out the instrument. There are three manual operations in the process that may instantly leak high concentrations of glutaraldehyde vapor, including: (1) opening the lid of the sterilizer and placing medical devices; (2) lifting the lid and placing alcohol after the sterilization step is completed; and (3) lifting the lid and removing the medical devices after the sterilization process is completed.

The hazards of glutaraldehyde to human health include:

Glutaraldehyde in water and vapor are irritating to the skin, eyes, throat, and lungs.

Glutaraldehyde may cause irritation of the skin, throat, nose and lungs. If allergic, it may cause

dermatitis

Rhinitis and conjunctivitis

asthma

If you have any of the above symptoms, you need to consult a physician specializing in occupational diseases.

Exposure and prevention

What is the permissible concentration standard for occupational exposure?

In order to prevent workers from being overly exposed to glutaraldehyde in the workplace and causing adverse health effects, my country's standards for the permissible concentration of harmful substances in the air of workers' working environments have set a maximum permissible concentration value of p0.2 ppm based on the strong irritation of glutaraldehyde to the respiratory tract. Some studies have suggested lowering this value to 0.05 ppm because environmental measurements have shown that many complaints still occur when the value is lower than the current setting of 0.2 ppm. The maximum allowable concentration value refers to the concentration that must not be exceeded at any time during operation. Therefore, efforts must be made to improve the working environment and/or working methods so that the exposure conditions can meet the preventive significance of setting this value.

How to determine the presence of glutaraldehyde?

The vapors generated when using glutaraldehyde can cause respiratory exposure to workers. Therefore, it is necessary to use appropriate sampling and analysis methods to measure the presence and concentration changes of glutaraldehyde in the workplace air in order to understand the workers' exposure status and the effects of improving the working environment and (or) working methods.

The sampling and analysis methods for glutaraldehyde vapor include: using a direct reader based on electrochemical principle, direct measurement using a Fourier transform infrared spectrometer (FTIR), sampling using a solid adsorbent and then combining it with gas chromatography analysis, or sampling using a derivatizing agent to form a glutaraldehyde derivative compound and then combining it with an appropriate analysis method. USA

The methods disclosed in OSHA 64 and NIOSH 2532 are based on 2,4-dinitrophenyl hydrazine (2,4-DNPH) derivatization technique for glutaraldehyde gas sampling, followed by high performance liquid chromatography. Detailed sampling and analysis procedures can be referred to the method and consulted with industrial hygiene professionals.

According to the aforementioned exposure tolerance concentration standard, the glutaraldehyde exposure at any time should not exceed 0.2 ppm. The permissible exposure sampling time is extremely short. However, in practice, the sampling time recommended by US OSHA 64 and NIOH 2532 is 5-15 minutes. According to our research on "Exposure Assessment of Glutaraldehyde in Medical Institutions", the probability of the highest concentration lasting for more than 5 minutes during the lid opening process of automatic disinfection machines used in medical institutions is low. Therefore, in the future, we may consider developing a sampling and analysis method that takes less than 5 minutes to meet actual needs.

Glutaraldehyde is a chemical that is harmful to health. Its use must be controlled so that the maximum concentration of personnel exposure is 0.2 ppm.

To achieve this standard, good operation is required, which includes careful selection of operating equipment, reasonable layout, smooth movement lines, correct operating methods and education and training of personnel. Specific suggestions are as follows:

Whenever possible, use less hazardous substances or products to replace glutaraldehyde-based disinfectants.

Glutaraldehyde cannot be used as a general cleaning disinfectant. According to our survey results in 2007, 2.6% of medical institutions improperly used glutaraldehyde for environmental cleaning.

Use glutaraldehyde in a well-ventilated or ventilation area.

Containers containing glutaraldehyde (including sinks that can be used for manual disinfection of medical devices) must be covered, and the time of uncovering should be shortened as much as possible.

When using an automatic disinfection machine, the time required to manually lift the lid should be shortened as much as possible.

When using glutaraldehyde, avoid skin contact, stay away from fire and reduce exposure to sunlight.

When handling glutaraldehyde, even highly diluted solutions, protective gloves, aprons, masks and goggles should be used.

It is recommended to use special respiratory protection measures when necessary. Do not spread glutaraldehyde products into the air without wearing a protective mask.

Used glutaraldehyde waste solution and (or) waste reagents must be properly handled and must not be discarded or poured into the sink at will.

Obtain complete Material Safety Data Sheets and other relevant information from product manufacturers or suppliers, and educate and train personnel on how, when, and where to use the products without endangering health.

Do ventilation conditions change exposure concentrations?

Glutaraldehyde should only be used in areas with ventilation or in well-ventilated areas. Under this principle, local exhaust control or mobile extractor

Unit) is a better choice and is often recommended in relevant safety and health guidelines abroad, but it does not seem to be a necessary measure. According to our survey of eight medical institutions in 1990, improving the ventilation volume of air conditioners and reducing the time of opening the cover during manual (and/or automatic) disinfection can help reduce the maximum concentration of glutaraldehyde in the air of the workplace, so that the maximum concentration of glutaraldehyde exposure meets the requirements of the standard. However, the effectiveness of this measure must be verified through individual case measurements.

Changing ventilation conditions can reduce the concentration of glutaraldehyde in the working environment air, but whether using local exhaust or dilution ventilation, the equipment needs regular inspection and maintenance.

Use of personal protective equipment?

The use of personal protective equipment should be considered as a last resort among all exposure precautions. Except in emergency response and temporary operations, exposure prevention for routine operations should be given priority over other measures. If other preventive measures cannot be implemented or are ineffective after implementation, consider using personal protective equipment. For example, when handling glutaraldehyde solution and there is a risk of splashing, personal protective equipment such as protective gloves, aprons, masks and goggles should be used; and when there is a concern about high concentration respiratory exposure, it is recommended to use respiratory protective equipment that can effectively filter out glutaraldehyde or other suitable respiratory protective equipment.

The use of personal protective equipment (especially respiratory protective equipment) must be extremely cautious because the source of glutaraldehyde does not change when the protective equipment is used. In order to use personal protective equipment prudently, supporting measures must be taken, including the formulation of a personal protective equipment (or respiratory protective equipment) plan by the safety and health management unit, and proper planning of the selection, distribution, cleaning, inspection, maintenance and user education and training of protective equipment.

What should you do if you think there is a problem?

If you encounter:

The product or container is not clearly labeled.

Inadequate product instructions or insufficient training of personnel.

Poor ventilation or broken ventilation equipment.

Personal protective equipment such as gloves or protective clothing is damaged.

The skin becomes red and swollen, the nose runs, and breathing becomes difficult.

Then you may want to:

Stop using glutaraldehyde products immediately.

Contact the supplier to use an alternative product.

Contact the manufacturer and reconfirm.

Communicate with the unit's safety and health management personnel and take feasible measures.