Irritation protection against

Hazard to be protected against, e.g. corrosive or irritant chemicals, heat, abrasion. 

The basis on which the TLVs are set may differ from substance to substance. For some, such as levels for silica dust, a guiding factor is protection against impairment of health. For others, it is the comfort level of the individual, such as freedom from irritation, nuisance, or other forms of stress for example, the TLV for sulfur dioxide is based on irritation and not on toxicity per se. The TLV list is reviewed annually resulting in some revisions in values and some additions to the list. 

The long-term OES is 50 ppm (8 hr TWA), set to protect against CNS effects, which will also protect against liver or kidney damage and irritahon. The short-term OES is 1000 ppm (15 minute reference period) to minimize exposures at irritant levels. 

Low secretion of saliva and less mucin in the produced saliva are not unusual in older individuals. Saliva has a number of protective functions of which the most important is protection against irritation by both chemical and mechanical trauma to... 

And there are suggestions that some type of cross-protection may occur, whereby exposure to ozone provides some protection against other irritant oxidants. Analogues for all these phenomena should be sought in human populations, and methods should be devised for assessing their significance for human health. 

In a well-ventilated hood, behind a safety shield, with equipment protective against skin irritation, a solution of 10 gm (0.0516 mole) of benzylnitroguani-dine in 165 ml of concentrated nitric acid is diluted with 100 ml of water. To the solution, cooled to 14°C, is added slowly a solution of 7.12 gm (0.103 mole) of sodium nitrite in 20 ml of water. 

In addition to oral administration for hepatitis C infection in combination with interferon alfa, aerosolized ribavirin is administered by nebulizer (20 mg/mL for 12-18 hours per day) to children and infants with severe respiratory syncytial virus (RSV) bronchiolitis or pneumonia to reduce the severity and duration of illness. Aerosolized ribavirin has also been used to treat influenza A and infections but has not gained widespread use. Systemic absorption is low (< 1%). Aerosolized ribavirin is generally well tolerated but may cause conjunctival or bronchial irritation. Health care workers should be protected against extended inhalation exposure. The aerosolized drug may precipitate on contact lenses. 

Wachtel(Ref 2) lists bromoacetone as first used in July 1915 in a war gas, called Martonite (BA 80 + chloroacetone 20%) in Ft, B-Stoff in Ger and BA in USA. This compd is a powerful lachrymator. In sprays, it causes, in contact with the skin, painful blisters, which heal within a short time. A concn of 1.5 mg/m3 causes tears immediately, 2.8 mg/m3 causes fighting inefficiency, 560 mg/m3 is toxic and 3200 mg/m3 is a lethal concn after 10 min exposure. Protection against the lachrymatory effect is possible by well-fitted goggles. Detection of BA in the field is easily made by odor irritation caused by the vapor(Ref 2)... 

Threshold limit values (TLVs) refer to airborne concentrations of substances and represent conditions under which it is believed that nearly all workers may be repeatedly exposed day after day without adverse effect. Because of wide variation in individual susceptibility, a small percentage of workers may experience discomfort from some substances at or below the threshold limit a smaller percentage may be affected more seriously by aggravation of a preexisting condition or by development of an occupational illness. Threshold limits are based on the best available information from industrial experience, from experimental human and animal studies, and when possible, from a combination of the three. The basis on which the values are established may differ from substance to substance protection against impairment of health may be a guiding factor for some, whereas reasonable freedom from irritation, narcosis, nuisance, or other forms of stress may form the basis for others. Three categories of TLVs follow ... 

BEIs are the concentrations of chemicals that are most likely to be observed in specimens (blood or urine) collected from healthy workers who have been exposed to chemicals to the same extent as workers with inhalation exposure at the TLV. The exceptions are the BEIs for chemicals for which the TLVs are based on protection against nonsystemic effects (such as irritation or respiratory impairment) where biomonitoring is desirable because of the potential for substantial absorption via an additional route of entry (usually the skin). The BEI generally indicates a concentration below which nearly all workers should not experience adverse health effects (ACGIH 2001). 

No signs of skin irritation were observed in rabbits after a 0.1% solution of white phosphorus in peanut oil was applied to the shaven intact skin (Lee et al. 1975). White phosphorus is highly reactive and is likely to be an irritant. It is possible that the peanut oil vehicle was protective against these potential effects. 

No evidence of skin irritation was observed in animals exposed to white phosphorus in peanut oil placed on the skin (Lee et al. 1975). The peanut oil vehicle may have been protective against the potential irritating effects of white phosphorus. 

Figure 1 Functions of enteric coatings according to the statements of the pharmaceutical manufacturer. 1, Taste masking 2, stability 3, protection against local irritation 4, drug release in specific parts 5, odor masking.

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