2002-07-08 - 10:23 a.m.
So here I am back at work, for yet another week. I guess I should be happy really. I still have a job, one that doesn�t outright suck. I am thankful for that. I guess when you get right down to it, there are a lot of things that I am thankful for. Maybe I will make a list someday.
Bad news at work today�9 of the 14 computer in my lab are down today. See what happens when you leave the branch for a week�people start breaking your toys, and then expect you to fix em when you get back. Bah�
I have decided that there area few things about summer that I really dislike. I dislike the extreme Humidity, the tourists, the way that folks get cranky when it gets hot, and most of all I dislike Air Conditioning. Yeah, you heard me right. I would even go so far as to say I really dislike Air Conditioning. It is an evil thing.
Now I am sure many of ya think that I have gotten too hot or something, and as a result, my brain is half-baked. Let me assure you though, that is not the case. The reason that I don�t care for AC is:
It makes you weak. (If you don�t believe me, try turning off the AC for a few days. Yes, in your house, car, and work if you can get away with it. See how long it takes you to become unhappy, cranky or the likes. On the flip side, try going in and out of the AC all day long. Do this for a few days. See how long it is till you get a cold.)
It is freaking expensive! Not just a little expensive�but VERY expensive. It used to cost me more to cool my house than it did to heat it. As far as your car goes, think of this. Every time you run the AC you loose up to 5 mpg, sap power from other components that need the power, and worst of all, you reduce the life of the engine. (You are making the vehicle run warmer, stress the components like the alternator, and lastly you force the engine its self to run harder to compensate for the extra load. Yeah perhaps in the long run you are talking a difference of 200k miles vs. 175k miles�but still, that is a lot.) And we all know what car repairs and parts replacement cost these days.
It is loud. Well ok many of the central systems are not that bad, but if you have window units like I do, it is loud.
I have to dress warmly for work, because it is 68 deg. While outside it is 98 deg. So when I head outside, I sweat like a pig (yes I know pigs don�t sweat�but I do!). There is no middle ground, at work I am either cold, or HOT.
Lastly, a body becomes acclimated to the surrounding conditions. If you are constantly jumping from one temp. extreme to another (a difference in 25 or 30 degrees many times) you body never gets used anything. Therefore, at work you get cold�while outside, you are unbearable hot.
AC air smells funny, is often stale, and laden with nasty things. All the air is processed and recycled. Think about it. If the AC is on, the house is closed up, therefore whatever impurities or other �things� that are floating about are only concentrated as the season wears on. Think about it, how often do you change your filters during the summer? How much do those filters really catch? I know the window units at my place need cleaning ever week or so�how often do you clean yours? How often does your work clean theirs?
That shit is bad for the environment. We all know it, and while we may recapture coolant (or what ever you call it�) there are plenty of uncaring unaware folk who don�t. Hmm�in fact I can count my self in that list. I know in my time I have had 4 car AC systems depressurize and release its �stuff� in to the atmosphere, and one window unit sent off to the dump without recapturing the coolant (or what ever).
Ok, perhaps I am a freak�maybe it is all the smithing work that I do has changed my perception of heat�who knows. But to tell ya the truth, I only turn on the AC in my place when I start worrying that my dog is getting too hot, or I have company (because most folks are used to the AC and not the heat, I try not to make my guests uncomfortable. That would be rude.) Normally, I just use ceiling fans, or use a small fan in the room that I am occupying. Ya know, your built in cooling system is really efficient if you ever give it the change to run properly. But with all the clothes that we wear to combat the AC, makes it hard for the body to cool its self with out outside help. Enh�now I am preaching�sorry. No wait, I am not sorry�this is my book.
Well I guess we all have our little hang-ups. Things that we dislike that is considered a social norm. And as a result we take a big ole pile of shit for it�but ya know what�I don�t care. I guess I understand the vegetarian thing a little better now Gen�ok well not really. But I respect your standing up to all the bullshit much more now�
I was given a good piece of advice the other day. I know I have gotten it before, and will probably hear it again, and again, and again. Be true to your self. Even if people don�t understand why�they will still respect you for staying true to your self. For when it really comes down to it, the only person that you ever have to answer to is you. And if you can live with your self�if you can honestly say you are happy with you�well then�fuck the rest of ya.
Today I learned that: Production of R12 or CFC-12 (Dichlorodifluoromethane) was halted by the clean air act on January 1, 1996. Today the remaining supplies are products, which have been recovered and reclaimed back to a chemically pure state in accordance with ARI-700 standards. The ARI standard is basically a virgin specification. The supply of virgin product is limited as most of the virgin was depleted in the first and second years after production ceased. PRODUCTION CEASED IN 1995. This is the stuff that does terrible this to the ozone. This is the stuff that you can still buy in Mexico. This is the stuff that is still being used all over the world.
So�just out of curiosity�What have you learned today?
Here is a little info about this wonderful stuff thanks to OSHA
So, how many of ya are really going to even look at this stuff anyhow�.Bet Tholen does, but I am curios who else will.
SUBSTANCE IDENTIFICATION
* Formula CCl(2)F(2)
* Structure (For Structure, see paper copy)
* Synonyms Refrigerant 12, freon 12, propellant 12, halon 122, difluorodichloromethane, FC 12, freon F-12.
* Identifiers
1. CAS No.: 75-71-8
2. RTECS No.: PA8200000
3. DOT UN: 1028 12
4. DOT label: Nonflammable gas
* Appearance and odor Dichlorodifluoromethane is a colorless gas with a characteristic ether-like odor; it is pressurized and used in liquid form. At concentrations below 20 percent by volume, dichlorodifluoromethane has no odor.
CHEMICAL AND PHYSICAL PROPERTIES
* Physical data
1. Molecular weight: 120.9
2. Boiling point (at 760 mm Hg): -29.8 degrees C (-21.6 degrees F)
3. Specific gravity (water = 1): 1.49 (at boiling point)
4. Vapor density: 4.2
5. Melting/Freezing point: -157.7 degrees C (-252 degrees F)
6. Vapor pressure at 20 degrees C (68 degrees F): 4332 mm Hg
7. Solubility: Nearly insoluble in water; soluble in most organic solvents.
8. Evaporation rate: Data not available.
* Reactivity
1. Conditions contributing to instability: Heat.
2. Incompatibilities: Contact between dichlorodifluoromethane and chemically active metals such as sodium, potassium, calcium, powdered aluminum, zinc, and magnesium should be avoided.
3. Hazardous decomposition products: Toxic gases and vapors such as hydrogen chloride, phosgene, and hydrogen fluoride may be released in a fire involving dichlorodifluoromethane.
4. Special precautions: None reported.
* Flammability BULLET TEXT = Dichlorodifluoromethane is nonflammable. The National Fire Protection Association has not assigned a flammability rating to dichlorodifluoromethane.
1. Flash point: Not applicable.
2. Autoignition temperature: Not applicable.
3. Flammable limits in air: Not applicable.
4. Extinguishant: Use an extinguishant that is suitable for the materials involved in the surrounding fire. Fires involving dichlorodifluoromethane should be fought upwind from the maximum distance possible. Keep unnecessary people away; isolate the hazard area and deny entry. Isolate the area for 1/2 mile in all directions if a tank, rail car, or tank truck is involved in the fire. Emergency personnel should stay out of low areas and ventilate closed spaces before entering. Cylinders of dichlorodifluoromethane may explode in the heat of the fire and should be moved from the fire area if it is possible to do so safely. If this is not possible, cool fire exposed containers from the sides with water until well after the fire is out. Stay away from the ends of containers. Personnel should withdraw immediately if a rising sound from a venting safety device is heard or if there is discoloration of a container due to fire. Firefighters should wear a full set of protective clothing and self-contained breathing apparatus when fighting fires involving dichlorodifluoromethane.
EXPOSURE LIMITS
* OSHA PEL The current Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) for dichlorodifluoromethane is 1000 parts per million (ppm) parts of air (4950 milligrams per cubic meter (mg/m(3))) as an 8-hour time-weighted average (TWA) concentration [29 CFR 1910.1000, Table Z-1].
* NIOSH REL The National Institute for Occupational Safety and Health (NIOSH) has established a recommended exposure limit (REL) for dichlorodifluoromethane of 1000 ppm (4950 mg/m(3)) as a TWA for up to a 10-hour workday and a 40-hour workweek [NIOSH 1992].
* ACGIH TLV The American Conference of Governmental Industrial Hygienists (ACGIH) has assigned dichlorodifluoromethane a threshold limit value (TLV) of 1000 ppm (4950 mg/m(3)) as a TWA for a normal 8-hour workday and a 40-hour workweek [ACGIH 1994, p. 18].
* Rationale for Limits The NIOSH limit is based on the risk of narcotic effects and possible asphyxia from vapor [NIOSH 1992]. The ACGIH limit is based on the risk of cardiac sensitization and systemic injury [ACGIH 1991, p. 421].
HEALTH HAZARD INFORMATION
* Routes of Exposure Exposure to dichlorodifluoromethane can occur through inhalation and eye or skin contact [Sittig 1991].
* Summary of toxicology
1. Effects on Animals: Dichlorodifluoromethane is a narcotic at high concentrations and an asphyxiant at very high concentrations in experimental animals. The LC(50) in rats, rabbits, and guinea pigs for a 30-minute exposure is 800,000 ppm. Exposure to 600,000 ppm dichlorodifluoromethane for 2 hours caused death in rats but not in guinea pigs [ACGIH 1991; Sax and Lewis 1989]. Mice exposed to 10,000 ppm for 24 hours survived but sustained lung tissue alterations. In dogs, monkeys, and guinea pigs exposed to 200,000 ppm for 40 hours per week for 10 to 12 weeks, generalized tremor and other signs of narcosis were noted. Microscopic liver injury was noted in guinea pigs exposed to 810 ppm continuously for 90 days, although no such injury was observed among rats, rabbits, dogs, and monkeys similarly exposed. Cardiac arrhythmias were observed in 5 to 12 dogs exposed both the 50,000 ppm dichlorodifluoromethane and exogenous epinephrine. Constriction of the airways has been noted in animals exposed to 50,000 to 100,000 ppm [ACGIH 1991]. The effects of direct eye contact with liquefied dichlorodifluoromethane under pressure are usually minimal, unless the eyelids are prevented from shutting, in which case temporary freezing of the eye surface may occur. Damage from this type of severe exposure resolved within 3 days [Grant 1986].
2. Effects on Humans: In high concentrations, dichlorodifluoromethane can cause narcosis, unconsciousness, cardiac arrhythmias, cardiac arrest, and asphyxiation, either as a result of dichlorodifluoromethane's narcotic effects or as a consequence of its displacement of oxygen in the atmosphere. Many nonoccupational deaths have been reported from the sniffing of fluorochlorinated hydrocarbon aerosols, including dichlorodifluoromethane; the mechanism of action in these cases is believed to be cardiac arrhythmias caused by sensitization of the myocardium to epinephrine [Hathaway et al. 1991]. Studies in volunteers showed that inhalation of 10,000 ppm of dichlorodifluoromethane for 2.5 hours caused a 7 percent reduction in standardized psychomotor scores; however, at 1,000 ppm for 8 hours/day, 5 days/week, for a total of 17 repetitive exposures, no abnormal responses occurred [Clayton and Clayton 1982]. Exposure to 40,000 ppm for 8 minutes caused generalized sensory losses, ringing in the ears, apprehension, and slurred speech; at 110,000 ppm for 11 minutes, there were cardiac arrhythmias, amnesia, and a marked decrease in consciousness [Hathaway et al. 1991]. An individual exposed to 150,000 ppm experienced loss of consciousness [Parmeggiani 1983]. Individuals with cardiac or respiratory disorders may prove especially susceptible to dichlorodifluoromethane [NLM 1995]. Contact with the liquid can cause frostbite because of the rapid evaporation of this chemical [Sittig 1991].
* Signs and symptoms of exposure
1. Acute exposure: The most common symptoms of exposure to dichlorodifluoromethane are those associated with narcosis, which include dizziness, drowsiness, trembling, irregular heartbeat, unconsciousness, and, if the concentration is extremely high, death through asphyxiation. If liquefied dichlorodifluoromethane contacts the eyes or skin, pain, redness, and then whiteness of the affected tissue may occur if the contact was sufficiently severe to cause frostbite. Blistering may occur after tissue is thawed [Hathaway 1991].
2. Chronic exposure: No signs or symptoms of chronic exposure to dichlorodifluoromethane have been reported in humans.
EMERGENCY MEDICAL PROCEDURES
* Emergency medical procedures: [NIOSH to supply]
5. Rescue: Remove an incapacitated worker from further exposure and implement appropriate emergency procedures (e.g., those listed on the Material Safety Data Sheet required by OSHA's Hazard Communication Standard [29 CFR 1910.1200]). All workers should be familiar with emergency procedures, the location and proper use of emergency equipment, and methods of protecting themselves during rescue operations.
EXPOSURE SOURCES AND CONTROL METHODS
The following operations may involve dichlorodifluoromethane and lead to worker exposures to this substance:
* The manufacture and transportation of dichlorodifluoromethane
* Formerly used as aerosol propellants for cosmetics, pharmaceuticals, insecticides, paints, adhesives, and cleaners (almost all fluorochloro-carbon-propelled aerosol uses were banned by EPA in 1978); used as a refrigerant in home and commercial air conditioners; used as a rocket propellant; used to prepare frozen tissue sections
* Used as a blowing agent for cellular polymers; used as a low-temperature solvent or diluent in fumigants for food sterilization, and as a solvent or degreaser in paints and varnish removers and in polymerization processes
* Used as a foaming agent in fire extinguishing aerosols; used in immersion quick freezing of food products; used to chill cocktail glasses
* Used in water purification; copper and aluminum purification, petroleum recovery, and in manufacture of glass bottles
* Used in regulating devices for leak detection; used in thermal expansion valves; used as insulators and generator windings in manufacture of materials for electrical applications
* Used in organic synthesis of freons and resins; used as a working fluid for heat pumps and in hydraulic fluids
Methods that are effective in controlling worker exposures to dichlorodifluoromethane, depending on the feasibility of implementation, are as follows:
* Process enclosure
* Local exhaust ventilation
* General dilution ventilation
* Personal protective equipment
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