品名

钛; Titanium; CAS：7440-32-6

二氧化钛; CAS：1317-70-0

四氯化钛; CAS：7550-45-0

三氯化钛; CAS：7705-07-9

磷酸钛盐; CAS：17017-57-1

理化性质

白色有光泽结晶和深灰色无定型粉末。元素符号Ti。原子量47.88。相对密度4.57。熔点1677℃。沸点3277℃。自燃点1200℃(块状); 250℃(粉末)。溶于氟氢酸、浓硫酸和硝酸(被硝酸氧化为二氧化物)中,加热时,也溶于盐酸中; 不溶于水。粉尘遇热、明火、火花燃烧、爆炸。用水扑灭燃烧着的钛能引起爆炸。钛还能在二氧化碳、氮气中燃烧。常见的化合物有二氧化钛(TiO2)、四氯化钛(TiCl4)、硫酸钛[Ti(SO4)3]和碳化钛(TiC)。

接触机会

在钛的各种合金治炼、飞机的发动制造以及造船和其它国防工业中可接触钛及其化合物。制造颜料及耐火材料中也可遇到钛及其化合物。

侵入途径

主要经呼吸道吸入。

毒理学简介

一般认为钛是无害的。

四氯化钛：大鼠吸入LC50: 400 mg/m3。小鼠吸入LC50: 100 mg/m3/2H。

磷酸钛盐：大鼠经口LD50: >15 gm/kg。

大鼠急性吸入TiCl4中毒后,钛离子随即在血内出现,一天后血钛含量减少20倍。肺是主要滞留器官,但中毒后6天,肺钛含量较中毒开始时减少极多。口服金属钛仅吸收3% 。皮下或腹腔内注射钛盐,在吸收前,长期存留在注射部位。大鼠静脉注射TiO2后,75%分布于肝,仅3%在脾,而上腹部肝区附近的淋巴结浓集量最高。

钛主要由尿排出,正常人尿钛浓度约为0.209μmol/L。

中毒机理:TiCl4及其水解物具有高毒性。由于TiCl4粉尘在潮湿空气中水解形成TiCl2(OH)2 和TiCl(OH)3,能进入肺深部,进一步水解为HCl而产生有害作用。

当狗吸入TiCl4粉尘后数小时发生由于严重支气管炎和肺水肿所致的呼吸困难,并可引起虚脱和死亡。肺部见局灶性充血和出血。SiCl4和TiCl4同时存在时,可见协同作用。

临床表现

吸入TiCl4烟雾尘,由于吸入量不同,引起不同程度的呼吸道刺激症状,有咳嗽、呼吸困难,气管炎及肺炎。

皮肤直接接触液体TiCl4可引起不同程度的灼伤。

美国HSDB引用文献--四氯化钛：

*... OBSERVED DAMAGE TO CORNEAS IN FIVE HUMAN BEINGS WHO HAD BEEN SEVERELY EXPOSED TO THESE FUMES, WITH PARTICULARLY SEVERE EFFECTS ON CORNEA IN PATIENTS WHO DIED FROM EXPOSURE. [R20]

*... ABOUT 50 L OF TITANIUM CHLORIDE @ TEMP OF 100 DEG C, WAS OPENED ... & OPERATOR WAS SPLASHED WITH LIQUID. FUMES OF TITANIC ACID & TITANIC OXYCHLORIDE ... WERE INHALED. SURFACE SKIN BURNS, ... MARKED CONGESTION OF MUCOUS MEMBRANE OF PHARYNX, VOCAL CORDS & TRACHEA, ... STENOSIS OF LARYNX, TRACHEA & UPPER BRONCHI ... . [R21, 334]

*... HIGH IRRITANT TO SKIN, EYES, & MUCOUS MEMBRANES & VIA INHALATION ROUTE. [R11]

*A case of endobronchial polyps following inhalation injury caused by titanium tetrachloride was investigated. A 50 year old chemical engineer was working on a glass pipe containing titanium tetrachloride when it broke, spraying his head, neck, chest, and back with the liquid. The patient was wearing a mask but removed it after running to a nearby sink to flush the material from his face and chest. For approximately 2 minutes he inhaled the vapor from a cloud that formed when the chemical was exposed to air. He was hospitalized in respiratory failure. Treatment involved endotracheal intubation, and ventilation therapy. Aspiration pneumonia was treated with antibiotics. Five weeks after admission, his chest X-ray was normal, but he developed progressive carbon dioxide retention and respiratory insufficiency requiring a return to ventilator therapy. Fiberoptic bronchoscopy demonstrated erythema of the entire bronchial tree with thickening of the carina and all of the lobar and segmental spurs. There were approximately 35 to 40 fleshy polypoid lesions on both sides of the bronchial tree, some isolated, others multiple, occluding bronchi at various segmental and subsegmental areas. Some lesions were pedunculated and demonstrated a ball valve effect occluding bronchi upon inspiration. Biopsies revealed granulation tissue with acute inflammation. Treatment was with high dose intravenous corticosteroids. Bronchoscopy 10 days later revealed a marked decrease in the number and size of the remaining polyps with approximately 15 now visible. One year after injury, bronchoscopy showed return to near normal of many of the previously stenotic lobar, segmental, and subsegmental bronchial orifices. /It was concluded/ that these polyps were compatible with a reparative process to the tracheobronchial injury. Diffuse bronchial polyposis should be considered as a cause of delayed respirator weaning in patients with inhalation injuries. [R23]

*The extremely low toxicity of titanium and several of its compounds (titanium salicylate, oxides, peroxide, and tannate) when in contact with skin and tissues has been demonstrated by its use in the therapy of skin disorders. The biocompatibility of titanium is high as shown by its vast use as an implant material in orthopedics, oral surgery and neurosurgery. The small amounts of titanium occasionally released from implants into adjacent tissues have not caused any adverse effects. /Titanium and its compounds/ [R6, 602]

处理

皮肤污染TiCl4时,先用布类吸去液体,再用清水反复冲洗。吸入TiCl4引起上呼吸道刺激症状时,可对症治疗。

卫生标准

车间空气卫生标准:

美国ACGIH TLV-TWA 10mg/m^3(TiO2粉尘)

参考文献

[1]Zitting A,et al. Biological activity of titaniumdi oxides.Int Arch Occup Environ Health 1979; 43:93.

[2]Zenz C. Occupational Medicine.2nd ed. Chicago:Year Book Medical Publishers, Inc.,1988:657. 　　　　

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