Corneal

Both Hquid HE and the vapor can cause severe skin bums which may not be immediately painful or visible. HE can penetrate skin and attack underlying tissues, and large (over 160 cm ) bums may cause hypocalcemia and other systemic effects which may be fatal. Even very dilute solutions may cause bums. Both Hquid and vapor can cause irritation to the eyes, corneal bums, and conjunctivitis. 

In humans, cases of dermatitis have been described after contact with DHBs. Combined exposure to hydroquinone and quinone airborne concentrations causes eye irritation, sensitivity to light, injury of the corneal epithelium, and visual disturbances (126). Cases with an appreciable loss of vision have occurred (127). Long-term exposure causes staining due to irritation or allergy of the conjunctiva and cornea and also opacities. Resorcinol and catechol are also irritants for eyes. 

Toxicology. The acute oral and dermal toxicity of naphthalene is low with LD q values for rats from 1780—2500 mg/kg orally (41) and greater than 2000 mg/kg dermally. The inhalation of naphthalene vapors may cause headache, nausea, confusion, and profuse perspiration, and if exposure is severe, vomiting, optic neuritis, and hematuria may occur (28). Chronic exposure studies conducted by the NTP ia mice for two years showed that naphthalene caused irritation to the nasal passages, but no other overt toxicity was noted. Rabbits that received 1—2 g/d of naphthalene either orally or hypodermically developed changes ia the lens of the eye after a few days, foUowed by definite opacity of the lens after several days (41). Rare cases of such corneal epithelium damage ia humans have been reported (28). Naphthalene can be irritating to the skin, and hypersensitivity does occur. 

Acute oral LD q data for nitro alcohols in mice are given in Table 1. Because of their low volatiHty, the nitro alcohols present no vapor inhalation ha2ard. They are nonirritating to the skin and, except for 2-nitro-1-butanol, are nonirritating when introduced as a 1 wt % aqueous solution in the eye of a rabbit. When 0.1 mL of 1 wt % commercial-grade 2-nitro-1-butanol in water is introduced into the eyes of rabbits, severe and permanent corneal scarring results. This anomalous behavior may be caused by the presence of a nitro-olefin impurity in the unpurifted commercial product. 

Instillation of pure thioglycolic acid iato the eyes of a rabbit resulted iu severe pain, severe conjunctival inflammation, dense corneal opacity, and severe idtis. These effects had not improved at the end of 14 d after exposure. Washing immediately after exposure did not modify the response (23). 

The hquid is irritating to the skin after only a few minutes of contact. The inhibitor MEHQ may be partiy responsible for this irritation. Inhibited vinyhdene chloride is moderately irritating to the eyes. Contact causes pain and conjunctival irritation, and possibly some transient corneal injury and iritis. Permanent damage, however, is not likely. 

In humans, vitamin A deficiency manifests itself in the following ways night blindness, xerophthalmia, Bitot s spots, and corneal involvement and ulceration. Changes in the skin have also been observed. Although vitamin A deficiency is seen in adults, the condition is particularly harmful in the very young. Often, this results from malnutrition (56). 

Repeated exposure of skin to Hquid tetrachloroethylene may defat the skin causing dermatitis. When frequent or prolonged contact is likely, gloves of Viton, nitrile mbber, or neoprene should be used, discarding them when they begin to deteriorate. Tetrachloroethylene can cause significant discomfort if splashed in the eyes. Although no serious injury results, it can cause transient, reversible corneal injury. If contact with skin or eyes occurs, foUow standard first-aid practices. 

Contact with eye tissue at normal temperatures causes pain, mild to moderate irritation, and possibly some transient corneal injury. Prompt washing with large quantities of water is helpful in minimizing the adverse effects of eye exposure. 

Toxicity of 2-Ghloroethanol. Ethylene chlorohydrin is an irritant and is toxic to the Hver, kidneys, and central nervous system. In addition, it is rapidly absorbed through the skin (73). The vapor is not sufficiently irritating to the eyes and respiratory mucous membranes to prevent serious systemic poisoning. Contact of the Hquid in the eyes of rabbits causes moderately severe injury, but in humans corneal bums have been known to heal within 48 hours. Several human fataUties have resulted from inhalation, dermal contact, or ingestion. One fatahty was caused by exposure to an estimated 300 ppm in air for 2.25 hours. In another fatal case, autopsy revealed pulmonary edema and damage to the Hver, kidneys, and brain (73). 

Water content indirectly affects other lens characteristics. Water evaporation from the lens can result in a dry eye sensation and subsequent desiccative erosion of the cornea. Clinical studies have shown the incidence of corneal erosion as a result of lens desiccation to be a material-dependent and water-content-dependent phenomenon (25,26). The nature of water and sodium ions in hydrogels has been studied primarily by nmr and thermal techniques (27,28). An empirical relationship between water mobility in contact lens polymers and desiccative staining has been proposed (29). 

There is great interest in developing soft lens materids that have high oxygen permeabdity and good wettabdity. Such lenses will provide patients with good comfort, high deposit resistance, and superior corneal health, particularly for extended wear appHcations. 

Direct eye contact with liquid produces injury, generally transient, to the corneal epithelium. The liquid is mildly imtating to the skin due to the degreasing effect repeated contact may cause dermatitis. Ingestion of substantial quantities of liquid can damage the mucous membranes, and produce acute effects ranging from mild discomfort to profound anaesdiesia. 

Defatting of the skin, rashes, irritation Conjunctivitis, corneal damage... 

Health Hazards Information - Recommended Personal Protective Equipment Goggles or face shield, rubber gloves Symptoms Following Exposure Inhalation causes headache, nausea, and irritation of nose and throat. Vapor irritates eyes liquid causes inflammation and corneal opacity. Contact of skin with liquid causes dryness and irritation. Ingestion causes headache, nausea, and irritation of mouth and... 

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