2.1 Hazards and Protection of Ozone on the Respiratory System
Ozone can be produced by the corona discharge of photocopiers and the ultraviolet radiation produced. Copiers can release 1 to 54 μg of ozone per copy. When the copier is placed in a smaller room, poor ventilation, especially in the summer when the temperature is high frequent copying, indoor accumulation of ozone can cause harm. Experiments have shown that high temperatures can enhance ozone toxicity. The main target organ of ozone is the respiratory system, the entire respiratory tract, including the fine bronchial tubes and alveoli can be stimulated and damaged. High concentration ozone can damage alveolar surface active substances, generate toxic free radicals, and react with sulfhydryl enzymes in the alveolar membrane to generate HO- 3, which can alter cellular metabolic processes by affecting the vitality of glutathione (GSH), glucose 6-phosphate dehydrogenase (G-6-PD) and lactate dehydrogenase (LDH), and through the cell membrane structure. and through lipids in the cell membrane structure should produce lipid peroxidation, leading to cell damage. In recent years, it has been reported that electrostatic photocopying can cause fibrosing alveolitis, which is common in long-term photocopying workers. The main symptoms are progressive shortness of breath and restrictive ventilatory dysfunction in lung function. Bronchopulmonary tissue biopsy can be seen in the alveolar wall thickening, vascular endothelial cell swelling, alveolar wall fibrous tissue hyperplasia. The reason for its occurrence is that the ultraviolet light produced by the high-voltage arc light in the electrostatic copying process can stimulate the oxygen in the air to change into ozone and nitrogen oxides, and ozone can cause pulmonary fibrosis. The impact of ozone on human health with the contact time and concentration increases and gradually aggravated, the human body instantaneous contact 0.02 ~ 0.1 mg / m3 of ozone can not be detected, the concentration of 0.2 mg / m3 human body can be detected; continuous inhalation of 0.4 ~ 2 mg / m3 ozone 1 ~ 3h can be caused by the middle and end of the bronchioles type Ⅰ and Ⅱ alveolar epithelial degenerative changes, there is shortness of breath, shortness of breath, Dry mouth, and can cause severe eye fatigue; inhalation of 2 to 4 mg/m3 ozone 2h can appear dry cough, sputum, headache, tongue numbness, chest tightness and reduced lung capacity and other symptoms; inhalation of higher concentrations (10 mg/m3 or more) of ozone can be life-threatening.
Site investigation also found that the concentration of nitrogen oxides with the extension of working hours and a significant increase. Ozone harm to the human body and indoor temperature, ozone concentration, the duration of the role of time, ventilation conditions and individual tolerance. Therefore, the copy room should be kept well ventilated, the operator should reduce the working time in the copy room, can be installed in the copy room special dual-use ventilation fan.
2.2 Damage to the nervous system and protection from hot melt gases
The toner and carrier coating materials used in photocopiers contain polybenzene, polypropylene resin, polyethylene, butadiene, xylene and other components. These substances can produce hot melt gas under the action of too high a temperature. For example, the use of substitute toner with a low melting point, frequent paper jams in the fixer to prolong the hot melt time of the toner, adjusting the image density of the copy, making too many full-ink copies, etc. will cause the toner to produce excessive hot melt gas due to the high temperature. In addition, part of the toner will repeatedly dissolve on the fixing roller and form a powder yoke, which increases the spacing between the thermistor and the fixing roller, resulting in an abnormally high fixing temperature to produce hot melt gas. These hot melt gas (such as NO2) is not only irritating to the human mucous membranes, but also with ozone and electrostatic induction and other joint action in the central nervous system, so that the tissue oxygen consumption increases, so that the normal physiological functions of the nervous system is disturbed, and even neurasthenia syndrome, according to the relevant research reports, long-term photocopying staff neurobehavioral function test results show that the experimental group of affective state test of fatigue, Inertia scores were significantly higher than those of the control group, and the total number of incorrect punches in the goal-tracking program and the digital span program scores were significantly lower than those of the control group. Photocopiers in the operation of the process of continuous exhaust containing carbon powder and corona discharge, electron tube discharge generated by ozone, nitrogen dioxide and other air ions are discharged. Ozone is an oxidizing agent that, when inhaled in higher concentrations, can form a variety of chemically active oxygen-containing compounds in the body, and such compounds can affect central nervous system function by interfering with biological metabolism. Copier generated air ions can also be with ozone, nitrogen dioxide to form a number of complexes and affect the physiological function of the human nervous system. A large number of air ions into the workplace, resulting in an imbalance in the proportion of positive and negative ions in the air, the imbalance of air ions into the human body, the body can make the bioelectricity is out of balance, which in turn affects the inhibitory process of nerve cell excitation. Therefore, it is recommended to clean the surface of the fixing roller and thermistor with acetone or pure alcohol every week in the cooling state of the copier, so as to reduce the generation of hot fusion gases and hazards.
3 Hazards and protection of harmful solids produced by copiers
3.1 Hazards of photoconductive drum production materials and their protection
Photoconductive drums are the core components of copiers. At present, the commonly used photoconductor materials for organic photoconductor (OPC), selenium alloy and cadmium sulfide. Cadmium sulfide has toxicity, 3-layer structure of cadmium sulfide photoconductor drum surface insulation layer can play a protective role, so the normal use of non-toxic. Selenium alloy photoconductive drums have selenium-tellurium alloy photoconductive drums, selenium-arsenic alloy photoconductive drums, selenium-arsenic-tellurium photoconductive drums and other types. Long-term exposure can easily cause chronic selenium poisoning and arsenic poisoning. Selenium and ozone are combined to generate SeO2, SeO2 and water are combined as colorless gas, and its odor is similar to the odor of garlic. This gas is absorbed quickly by the respiratory tract and has a strong irritating effect on the mucous membranes of the eyes, nose, throat, etc. It can dilate the capillaries, causing symptoms such as bleeding in the lungs and gastrointestinal tract, menstrual disorders, miscarriage, and even pulmonary edema. Therefore, when purchasing a copier, it is recommended to use non-toxic OPC photoconductive drums. When replacing photoconductive drums, extra care should be taken to prevent the drum surface from breaking, resulting in the leakage of radioactive materials. End-of-life photoconductive drums should be buried or recycled by manufacturers to avoid radiation hazards.
3.2 Hazards of developer dust on the human body and protection
The carrier material of the two-component developer used in the copier and the single-component developer in the iron oxide powder particle size is very small, with inhalation toxicity. The main component of the developer is carbon black, which contains polycyclic aromatic hydrocarbon impurities are strong carcinogens. The developer and cleaner of the copier have gaskets, but it is difficult to completely avoid developer leakage. Developer moisture or not timely replacement of the aging cut-off body, developer and photoconductor drum gap is too large, the cleaner recovery scraper or cleaning roller aging deformation, the cleaner in the waste powder plate orange blockage, developer or cleaner gasket severe wear and tear, as well as eliminating the jamming of undefined toner splash and accumulation, etc., in the maintenance of the surrounding air may result in the dust content of more than the limit limit value (10 mg / m3). It is recommended to clean the machine cavity with a vacuum cleaner once a week. The copier should not be overfilled when replenishing the toner to prevent black powder from leaking and flying when the machine is working. The operator of the copier should wear working clothes, working cap and protective glasses when working, and wear protective mask and gloves when repairing the machine or replacing the toner to minimize the hazards of the developing powder to human body. In the daily work to develop good personal hygiene habits and maintain environmental hygiene.
4 Hazards of ultraviolet radiation generated by the copier and protection
Copier exposure lamps are mostly quartz tungsten halogen lamps, and the ultraviolet radiation generated has a strong carcinogenic effect. So be sure to cover the light shield when operating to avoid damage to the cornea, head and neck, face and arms and other exposed parts. It is recommended to wear protective glasses to avoid eye irritation and damage from strong light.