Human category

The International Agency for Research on Cancer states that there is sufficient evidence for the carcinogenicity of TCE in experimental animals and classifies it as being probably carcinogenic to humans (Category 2B). 

Fig 3.10 Chemicals linked to developmental damage in humans category 2. 

Benzal chloride is almost exclusively used for the production of benzaldehyde. Benzal chloride is toxic and classified as a suspect carcinogen to humans (Category II-I B). These reasons require stringent measures for its handling, such as consequent sealing of the production equipment and regular medical inspection of the personnel. 

Phytoalexins are low molecular weight compounds produced in plants as a defense mechanism against microorganisms. They do, however, exhibit toxicity to humans and other animals in addition to microbes (30). Coumarins, glycoalkaloids, isocoumarins, isoflavonoids, linear furanocoumarins, stilbenes, and terpenes aU. fall into the category of phytoalexins (31). Because phytoalexins are natural components of plants, and because their concentration may increase as a response to production and management stimuli, it is useful to recogni2e the possible effects of phytoalexins in the human diet. 

Sutures are regulated by the EDA as medical devices iatended for human use. The Eederal Eood, Dmg, and Cosmetic Act of 1938 has been amended many times, ia particular by the Medical Device Amendments of 1976. Devices have been under the jurisdiction of the EDA siace 1938. Section 513 of the Act requires the EDA to classify medical devices (sutures) ia one of three categories as follows. 

Agriculture consumes by far the most of any use category to which the accessible mnoff worldwide is appHed (Table 6). Postel and co-workers estimate that human uses make up 26% of total terrestrial evapotranspiration and 54% of the mnoff geographically and temporally accessible (9). Increased use of evapotranspiration will confer minimal benefits globally because most of the land suitable for rain-fed agriculture is already in production. New dam constmction could increase accessible mnoff by about 10% over the next 30 years however, population increase during that period is projected to be more than 45%. 

Milk. Imitation milks fall into three broad categories filled products based on skim milk, buttermilk, whey, or combinations of these synthetic milks based on soybean products and toned milk based on the combination of soy or groundnut (peanut) protein with animal milk. Few caseinate-based products have been marketed (1,22,23). Milk is the one area where nutrition is of primary concern, especially in the diets of the young. Substitute milks are being made for human and animal markets. In the latter area, the emphasis is for products to serve as milk replacers for calves. The composition of milk and filled-milk products based on skim milk can be found in Table 10. Table 15 gives the composition of a whey /huttermilk-solids-hased calf-milk replacer, which contains carboxymethyl cellulose (CMC) for proper viscosity of the product. 

Air pollutants may be classified into two broad categories (I) natural and (2) human-made. Natural sources of air pollutants include ... 

The potential for a wide range of human errors is greater in batch processes than in continuous processes. Some examples can be found in the categories of errors in Exhibit 6.2. 

Suspected human carcinogens - see TLV Appendix A, Category A2 (below). 

The testing of chemicals/wastes to establish the nature of their hazard capacity/threat in accordance with regulatory requirements falls into four categories (1) reactivity, (2) ignitability/flammability, (3) corrosivity, and (4) EP toxicity. Commercial chemical products, specific wastes, and wastes from specific processes may be listed as hazardous wastes because they are known to present toxic hazards in the manner of the tests above and/or are known to present serious toxic hazards to mammals/humans. In the discussion to follow, various chemical groups will be examined primarily in the context of reactivity, ignitability, and corrosivity. 

The ESDs were then translated into associated event trees. A generic event tree was developed for all initiators not involving LOCA. The generic transient event tree for each category of the transient initiators and loss of offsite power were specialized by the impact of the initiators on the safety and support systems, from the success criteria of the mitigating systems, and the initiator-specific human actions which were modeled in the fault trees. 

Scientific information for the process of establishing OELs may come from human or animal data obtained using different methods, from studies of acute, subacute, and chronic toxicity through various routes of entry. Human data, which is usually the best source, is not easily available, and frequently it is incomplete or inadequate due to poor characterization of exposure and clear dose-response relationships. Human data falls into one of the following categories ... 

Insights into the human causes of accidents for a specific category of process plant installations are provided by the Oil Insurance Association report on boiler safety (Oil Insurance Association, 1971). This report provides a large number of case studies of human errors that have given rise to boiler explosions. 

In the case of a latent human error the consequences of the error may only become apparent after a period of time when the condition caused by the error combines with other errors or particular operational conditions. Two types of latent error can be distinguished. One category originates at the operational level and leads to some required system function being degraded or unavailable. Maintenance and inspection operations are a frequent source of this type of latent failure. 

For the sake of completeness, it is also useful to define at this stage the category of errors known as violations. Violations occur when a worker carries out actions that are either prohibited or are different from those which are prescribed by the organization and carry some associated risks. Since violations are deliberate acts, they are not, strictly speaking, errors. However, the violations category is useful when classifying human caused failures. 

Motivational campaigns are one way of dealing with routine violations (see Section 2.5.1.1). They are not directly applicable to those human errors which are caused by design errors and mismatches between the human and the task. These categories of errors will be discussed in more detail in later sections. 

In the nex - section of this chapter, some application areas for PIF analyses will be described. This will be followed by a classification scheme for PIFs based on the demand-resource mismatch model of error described in Chapter 1, Section 1.6. Subsequent sections will describe each of the PIF categories in turn, followed by examples where appropriate. These sections are followed by a discussion of the effects of interactions between PIFs and the implications of high levels of stress in emergencies for human performance. 

In a process disturbance, the suddenness of the onset of the event will also play a significant role in human performance. This category refers to the time required for the process symptom to develop to the extent that it becomes detectable by the workers. If the s3unptom develops gradually, this leaves some scope for the workers to switch to a high mode of alertness. This allows them to develop an adequate mental model (see Chapter 2) of the process state. If an adverse condition develops extremely slowly it may not be detected by workers, particularly if its development spans more than one shift. 

The term control panel refers to the instrumentation console in a central control room through which process information is communicated to the process worker and via which the worker changes the state of the process. This category includes display elements such as chart recorders, bar indicators, dials, and modem VDU-based systems together with control elements such as buttons, switches, track balls and mice. The control panel is the human-machine interface (see Chapter 2) that has traditionally received the most attention from human factors specialists. 

---