Para-dichlorobenzene

Para-dichlorobenzene
General
Systematic name	1,4-Dichlorobenzene
Other names	p-Dichlorobenzene p-DCB PDB Paramoth Para crystals Paracide
Molecular formula	C6H4Cl2
SMILES	c1cc(ccc1Cl)Cl
Molar mass	Molar mass::147 g/mol
Appearance	White crystalline solid with a mothball-like odor
CAS number	CAS number::106-46-7
Properties
Density and phase	[[Density::1.2475 g/cm3]]
Solubility in water	0.008 g/100 ml (20°C)
Melting point	Melting point:: 52.7°C
Boiling point	Boiling point::174°C
Hazards
MSDS	Material safety data sheet
Main hazards	Suspected carcinogen
NFPA 704	2 2
Flash point	66°C
R/S statement	R: R36 R40 R50/53 S: S2 S36/37 S46 S60 S61
RTECS number	CZ4550000
Related compounds
Related compounds	1,2-Dichlorobenzene 1,3-Dichlorobenzene
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Disclaimer and references

Paradichlorobenzene is a white crystalline compound, with a penetrating odor, made by chlorinating benzene and is used prominently as a moth repellent and deodorizer. Paradichlorobenzene is a water-insoluble solid. It is also a health hazard for both humans and animals.

Properties

Paradichlorobenzene is colorless to white solid crystal with a strong pungent odor. Humans are able to detect Paradichlorobenzene at airborn concentrations of 15ppm.

Para-dichlorobenzene is a chlorinated aromatic hydrocarbon compound used as a fumigant insecticide and repellant.

Para-dichlorobenzene, when exposed to air it slowing purifies from a solid into a vapor. The vapor form is what the person uses as a exposure route to kill its planned victim; insect, mold, or mildew. Para-dichlorobenzene has a moderate octanol and water partition coefficient. It also has low water solubility and moderate vapor pressure. Through atmospheric photo-oxidation Para-dichlorobenzene is transformed and degraded. The chlorobenzenes are mainly known for being chemically stable and when micro-organisms are not present for degradation then their chemical degradation in the environment is limited.

Health and Enviromental Effects

One of the many moths that are victims to parachlorobenzene

You can be exposed to paradichlorobenzene if you inhale it, get it on your skin, or if you consume it. It is most common to be exposed to paradichlorobenzene just by breathing it.

If you are briefly exposed to paradichlorobeneze you will experience nausea, vomiting, dizziness, fatigue, and headaches. The vapor can also exasperate your eyes and nasal passages. If the pesticide comes in contact with your skin for a long period of time, it can cause a burning sensation. If a pet eats a mothball that is made of paradichlorobenzene, it may vomit, have tremors, and abdominal pain. It can also cause kidney and liver problems to animals.

In humans, when paradichlorobenzene enters the body, it is distributed in the fat, blood, and breast milk. Then is broken down, by the body, into many other chemicals and excreted by urine. The effects vary.

In animals, paradichlorobenzene is quickly absorbed through the gut or lungs, but is absorbed much more slowly through the skin. Paradichlorobenzene has been found in their fat, liver, and kidneys. Smaller amounts of paradichlorobenzene were found in the blood plasma, lungs and muscle. Once the exposure had stopped the paradichlorobenzene was eliminated from their body. When animals were exposed for a long time, their bodies would start to break down the paradichlorobenzene faster, and the tissue levels declined.

Most of paradichlorobenzene that gets into the environment will turn into vapor. Paradichlorobenzene can also be broken down by bacteria or become attached to sediments in water. Paradichlorobenzene can be taken up by plants and the leaves on the plant may also absorb paradichlorobenzene just from the air. Paradichlorobenzene is broken down gradually by other chemicals in the air. It has been found in rain and snow. In the air, its half-life is about 31 days.

Researches fed 10 ducks for 35 days a diet that contained .5% paradichlorobenzene, and three ducks died and the rest did not grow normally.

Uses

Para-dichlorobenzene is mainly used in mothballs and similar products that are used to protect clothing from moths. But how every individual uses Para-dichlorobenzene products varies widely. Deodorant blocks also use Para-dichlorobenzene for restroom toilets and trash containers. Warnings for products with Para-dichlorobenzene can range from cautious to dangereous. It all depends on the combined toxicity of the active ingredient and the other ingredients that the product contains.

Mothballs

Paradichlorobenzene is an active ingredient in making mothballs

A mothball is a solid, used to kill moths and other insects because it gradually discards a toxic gas. In the United States, mothballs have a very high concentration of either paradichlorobenzene or naphthalene as their active ingredient.They are indicated to be used in an airtight (closed) container, in order for the fumes the mothballs produces to be trapped. Slowly the trapped fumes grow and kill all the clothes moths inside. Touching, eating, or breathing the mothball's fumes that are being used out in the open, can harm people, pets, or wildlife.

Video

Demonstrating the difference between melting and dissolving using Para-dichlorobenzene (mothballs).