Second degree burns

Late Toxicity Data not available Vapor (Gas) Irritant Characteristics Vapors are moderately irritating such that persoimel will not usually tolerate moderate or high concentrations liquid or Solid Irritant Characteristics Causes smarting of the skin and first-degree burns on short exposure may cause second-degree burns on long exposure Odor Threshold Data not available. 

Pain threshold reached after 8 s second degree burns after 20 s... 

Topical corticosteroids exert localized anti-inflamma-toiy activity. When applied to inflamed skin, they reduce itching, redness, and swelling. These drugs are useful in treating skin disorders, such as psoriasis, dermatitis, rashes, eczema, insect bite reactions, and first-and second-degree burns, including sunburns. 

A quantitative estimate of hazard distances for a variety of events, e.g. vapour dispersion to 50% LEL from pipework releases, up to second degree burns from a fireball. 

Dermal (skin) contact with sulfur mustard agents causes erythema and lesions (blistering), while contact with vapor may result in first and second degree burns contact with liquid typically produces second and third degree chemical burns. Any burn area covering 25 percent or more of the body surface area may be fatal. Respiratory contact is a dose-related factor in the sense that inflammatory reactions in the upper and lower airway begin to develop several hours after exposure and progress over several days. 

Second degree—burns more than 0.1 mm deep, affecting the epidermis and forming blisters. 

Figure 5-16 (SFPE, 2002) shows a method for predicting first and second degree burns based on heat flux and time. By knowing the exposure flux, one can predict the time to injury. No safety factor is included in this calculation the estimate is for bare skin, unprotected by clothing.

Figure 5-16. Prediction of First- and Second-Degree Burns...

Assuming that people are impeded by obstructions and are only able to move to a maximum distance of 5 m away from the fire, what is the potential for injury Using Figure 5-16, a person within 20 m of the fire would experience first- and second-degree burns within 3 and 6 seconds, respectively. 

The times to first and second degree burns are quite fast, indicating that people would need to escape to much further distances to be safe. 

From Figure 5-16, an incident heat flux of 8.6 kW/m will produce first-degree burns on unprotected personnel within 10 seconds and second-degree burns within 17 seconds. 

Prolonged skin contact with the liquid results in both systemic toxicity and the formation of large vesicles after a latent period of several hours. The affected skin may resemble a second-degree thermal burn. 

Liquid anhydrous ammonia in contact with the eyes may cause serious injury to the cornea and deeper structures and sometimes blindness on the skin it causes first- and second-degree burns that are often severe and, if extensive, may be fatal. Vapor concentrations of 10,000 ppm are mildly irritating to the moist skin, whereas 3 0,000 ppm or greater causes a stinging sensation and may produce skin burns and vesiculation. With skin and mucous membrane contact, burns are of three types cryogenic (from the liquid ammonia), thermal (from the exothermic dissociation of ammonium hydroxide), and chemical (alkaline). ... 

In humans, the liquid on the skin causes severe primary irritation and second-degree burns with vesiculation. Workers exposed daily at 5-10 ppm complained of irritation of the nose, throat, and eyes and, in some instances, headache and flushing of the skin of the face. Concentrations of 10-25 ppm are unpleasant and even intolerable to some subjects for exposure of more than a few minutes duration daily exposures of workers to less than 5 ppm (usually 1-2 ppm) resulted in no symptoms. ... 

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