Respiratory exposure dust inhalation

Due to the low volatility of cyromazine and the use of water-soluble bags for packaging the Trigard formulation, the main routes of exposure were expected to be from direct contact with the product or spray mixture on contaminated surfaces. Previous experience with pesticides worker exposure studies indicated that exposure from vapors or spray mist would be a minor factor. This can easily be confirmed by the PHED or similar published sources however, the extent of exposure from inhaling the product as dust is less well known. This route of exposure was also assumed to be minor, particularly with the use of water-soluble bag packaging. Given the low mammalian toxicity of cyromazine, the operators did not wear respiratory protection. 

Fatal poisonings have occurred after oral, dermal, and inhalation exposure to parathion. The vapor pressure of the pure compound is generally not sufficient to lead to respiratory exposure alone. However, fine dusts or aerosol preparations may result in severe poisoning through the respiratory tract. 

Cobalt is an essential element. Its deficiency can result in pernicious anemia. It is present in vitamin B12. Excessive intake of this element may result in polycythemia or overproduction of erythrocytes and heart lesions. Exposure to its dusts can produce cough and respiratory irritation. Chronic inhalation of its dusts or fumes can decrease pulmonary functions and may cause diffuse nodular fibrosis and other pulmonary diseases. Skin contact may induce dermal hypersensitivity reactions, producing an allergy-type dermatitis. 

Fluoride dust (as fluoride) Irritating to eyes and respiratory tract. Workers exposed to levels 10 mg/m suffered nasal irritation and bleeding. Lower-level exposures have produced nausea and eye and respiratory tract irritation. Chronic overexposures may result in skin rashes. Fluorosis, a bone disease with chronic high-level fluoride ingestion, is not associated with occupational dust inhalation. See also p 200. 2.5 mg/m (as F) 250 mg/m (as F) Appearance varies with the compound. Sodium fluoride is a colorless to blue solid. 

Respiratory protection products or respirators are classified on the basis of the achieved applied protection factor (APF). This is the factor by which the exposure by inhalation is reduced as the protection equipment is used in the required manner. Dust filters are positioned in three classes FFPl, FFP2 and FFP3, usually called PI, P2 and P3 respectively. They provide protection against powders or aerosols or both. 

Magnesium vanadates, as vanadium compounds in general, are known irritants of the respiratory tract and conjunctiva. The threshold limit value (TLV) for vanadium compounds in air recommended by the National Institute of Occupational Safety and Health is 0.05 mg/m based on a typical 8-h workday and 40-h workweek (7,147). Chronic inhalation can lead to lung diseases such as bronchitis, bronchopneumonia, and lobar pneumonia. These dust-related effects can be avoided by use of individual respirators in areas where exposure is likely. 

Acute effects of overexposure are as follows. Exposure to dust may cause mechanical irritation of the eye. PPS is essentially nonirritating to the skin, although freshly molded material may occasionally cause dermatitis. Inhalation of PPS dust may cause mechanical irritation to mucous membranes of nose, throat, and upper respiratory tract. 

Inhalation of crystalline or fused vitreous silica dust, usually overlong periods, causes a disabling, progressive pulmonary disease known as silicosis (84). Amorphous siUcas have not been linked to siUcosis (85), but can cause respiratory irritation. The history and poHtics of siUcosis have been reviewed (86). Standards have been set or recommended for occupational exposures (87,88) and review articles on the health effects of siUca are available (83,89). 

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