MPC of hydrocarbons: chemical factors of the working environment

2024 Author: Howard Calhoun | [email protected]. Last modified: 2024-01-02 13:48

Pollution of air and water with various kinds of chemicals has an extremely adverse effect on the state of the environment. At any modern enterprise, of course, various environmental standards must be observed without fail. This will guarantee the safety of both the workers of the plant and the people living next to it.

There are many chemicals that can have a harmful effect on the human body. For example, at the moment in Russia certain standards for hydrocarbons MPC have been developed. Today, unfortunately, such compounds account for about 70% of all pollution in the atmosphere. Comply with the standards for hydrocarbon concentrations, for example, enterprises of the chemical industry and oil refining.

Why MPC norms are provided

Harm of various kinds of chemicals, including hydrocarbons, can actually cause very serious harm to a person. Therefore, the standards also provide for the maximum permissible concentrations (MPC) of certain compounds. Such documents are developed so that the chemicals contained inair, did not primarily cause human he alth problems or diseases. Also, when calculating such norms, experts take into account such a factor as the impact of connections in the long term for the current and subsequent generations.

What are hydrocarbons

In total, our country has MPC standards for more than 1,200 different kinds of chemicals. Actually hydrocarbons are called organic substances, consisting only of hydrogen and carbon atoms. In chemistry, such compounds are considered basic. All other substances in many cases are considered as their derivatives.

In nature, hydrocarbons are found both in liquid and in solid or gaseous state. Among other things, there are concentrated deposits of such substances on our planet.

Types of hydrocarbons

All such substances are divided primarily into open or acyclic and closed (carbocyclic). The first type of compounds is classified into:

• saturated - methane, alkanes, paraffins;
• unsaturated with multiple bonds - olefin hydrocarbons, acetylenic, diene.

Saturated compounds of the methane group are the main part of oil and oil products, as well as natural combustible gases.

Carbocyclic hydrocarbons, in turn, are divided into:

• alicyclic;
• aromatic.

The latter type of compounds may also be present in oil. However, substances in this group rarelydominate in its composition over other hydrocarbons.

Also, all hydrocarbons are classified into:

• marginal (С2-С5);
• unlimited (С1-С10).

Which enterprises should be monitored

The sphere of use of compounds of groups C2-C5 and C1-C10 in the national economy is currently very wide. Control over compliance with the MPC of mixtures of hydrocarbons should be carried out first of all, of course, at oil and gas processing enterprises. Also, such compounds are quite widely used:

• in the chemical industry;
• fuel;
• easy;
• food;
• in agriculture.

Hydrocarbons are produced at the same time, including in our country, at the fields:

• oil;
• gas;
• coal;
• oil shale.

Most common hydrocarbons and related substances

Harm people and the environment, so all compounds in this group can. But most often a person is faced with the negative influence of the following types of substances:

• hydrogen sulfide (contained in hydrocarbon gases);
• carbon dioxide (produced by burning hydrocarbons);
• fuel gasoline and its vapors (contain hydrocarbons);
• benzapyrene;
• acetone (derivative of hydrocarbons), etc.

Harm to the human body

Some types of C2-C5 and C1-C10 are capable of exerting on people even veryserious mutagenic influence. That is why enterprises must strictly comply with the standards for MPC in the air of the working area, oil hydrocarbons, etc. First of all, such compounds harm the human cardiovascular system. Also, with a long stay in an environment with a high concentration of hydrocarbons, people usually change their blood counts for the worse. First of all, the level of hemoglobin and erythrocytes decreases in the victims.

Also, when the MPC in the air is exceeded, hydrocarbons can have an extremely negative effect on the liver of people. In addition, such compounds cause significant harm to the endocrine system. With prolonged exposure to a person, the work of the endocrine glands is disrupted. In addition, such substances have extremely harmful effects on the nervous system and lungs.

On a city scale, hydrocarbons, among other things, are capable of forming the so-called photochemical smog. In the process of complex transformations in atmospheric air, extremely toxic substances are formed from compounds of this type. These can be, for example, aldehydes or ketones.

The harm of hydrogen sulfide and carbon dioxide

These two substances can become very dangerous for the human body under certain conditions. Being in an environment saturated with hydrogen sulfide at a concentration of 0.006 mg/dm3 for 4 hours, for example, can lead to such negative consequences as:

• headache;
• photophobia;
• runny nose;
• lacrimation.

Whenan increase in concentration to 0.2-0.28 mg / dm³ in a person there is a burning sensation in the eyes, irritation in the nose and throat. An increase in the amount of hydrogen sulfide by 1 mg / dm^{3 leads to acute poisoning, accompanied by convulsions, loss of consciousness and ultimately ending in death. Especially carefully at the enterprises, the standards regarding the MPC of a mixture of hydrogen sulfide with hydrocarbons must be observed. In combination, these substances can cause even more harm to people than individually.}

Carbon dioxide, formed during the combustion of hydrocarbons, has a narcotic effect on the human body. Also, this substance has an irritating effect on the mucous membranes of people. As a result of its prolonged exposure, the following negative symptoms are observed in victims:

• dizziness;
• cough;
• high blood pressure.

When inhaling very high doses of carbon dioxide, a person can even die. Lethal outcome, for example, leads to staying in a room where the concentration of this substance in the air reaches 20%.

The harm of gasoline

This fuel, which is a product of oil refining and contains a large amount of hydrocarbons, can be extremely dangerous for both humans and the environment. For example, just 300 g of gasoline spilled during refueling pollutes 200 thousand m3 air.

Regulations regarding MPCs of oil hydrocarbons in the air when using gasoline must therefore be observed inaccuracy. When inhaling the vapors of this fuel for some time, a person experiences:

• headache;
• dizziness;
• sweating;
• feeling drunk;
• sluggishness;
• nausea, vomiting, etc.

It is believed that mild poisoning with gasoline vapor occurs after 5-10 minutes of a person's stay in a room with their concentration in the range of 900-3612 mg/m³. At the same time, with an increase in this indicator to 5000-10000 mg/m^{3, an acute toxic damage to the body occurs. A person's body temperature drops, pulse drops, etc.}

The harm of benzapyrene

This substance belongs to the class of aromatic hydrocarbons. Benzopyrene is formed, for example, during the combustion of liquid and solid organic substances (including petroleum products), wood, anthropogenic waste. Of the natural sources of release of this substance into the air, forest fires and volcanic eruptions can be noted above all.

A lot of benzapyrene is released when smoking. Road transport is also a source of air, water and soil pollution with this substance.

Like many other hydrocarbons, the MPC of which must be strictly controlled, benzapyrene belongs to substances of the first hazard class. It can enter the human body by inhalation, through the skin, as well as with food and water. At the same time, in addition to the carcinogenic effect, this compound is capable of exerting mutogenic, hematotoxic, and embryotoxic effects on humans.

Harm of acetone

This substance may have adverse effectson the human body at concentrations in the air above 500 parts per million. The main symptoms of acetone vapor poisoning are dizziness and nausea. If an employee of the enterprise is constantly exposed to this substance, his immunity will definitely decrease and respiratory diseases will develop in the future.

Maximum permissible concentrations in the air of the working area

According to regulations, MPCs of hydrocarbons in the working area should not exceed 300 mg/m³. At the same time, for an average daily period of time, a one-time maximum indicator should not exceed 900 mg/m^3.

Of course, the regulations also provide for maximum performance for specific types of hydrocarbons. So, according to the federal law, MPCs are provided in the working area for various types of hydrocarbons (and related substances):

• benzapyrene - 0.00015 mg/m3;
• gasoline - 300mg/m3;
• acetone - 0.9 mg/m3;
• hydrogen sulfide - 10 mg/m³ (mixed with hydrocarbons - 3 mg/m^3);
• oil - 10 mg/m3;
• carbon dioxide - 27000 mg/m3 (single dose).

Maximum Permissible Concentrations in Water

MACs for hydrocarbons in drinking water, of course, are also provided for by the regulations. Organizations supplying HB and HB to the population should first of all monitor the concentration of compounds of this type of aromatic group in it. So, for example, drinking water should not contain more (according to Russian SanPiN standards):

• benzene - 10 mcg/cm3;
• styrene - 100 mcg/cm3;
• benzapyrene - 5 mcg/cm3.

Natural water bodies should contain, for example, no more than:

• oil - 0.3 mg/m3;
• gasoline - 0.1 mg/m3.

Permissible concentrations in soil

The earth, of course, should not be polluted with various kinds of hydrocarbons. Standards in Russia regulate the maximum concentrations of various chemicals, including hydrocarbons, in agricultural soils, settlements, sanitary protection zones of water sources, resorts and individual enterprises.

According to the standards stipulated by the federal law, for example, the following MPCs for oil hydrocarbons are provided for in the land:

• for benzapyrene - 0.02 mg/kg;
• for gasoline - 0.1 mg/kg.

Saturated hydrocarbons

Both limiting and unsaturated compounds of this variety can cause significant harm to human he alth. Of course, the standards, of course, also regulate the MPC of saturated hydrocarbons. Such compounds, in turn, are divided into:

• alkanes;
• cycloalkanes.

Examples of saturated hydrocarbons are methane, butane, ethane. Some other substances also belong to this group. The standards provide for MPC for saturated hydrocarbons in the working area, as well as for unsaturated compounds, at 300 mg/m3. Compliance with these rules will guarantee work safetyenterprise personnel.

Russian Legislation

When the MPC of hydrocarbons in the working area of the enterprise is exceeded, the he alth of workers, as we found out, can actually be significantly harmed. The responsibility for this, of course, lies primarily with the employer. It is the administration that should carry out the most thorough control over the concentration of harmful substances in the air of the plant's shops.

The legislation of Russia in terms of the MPC of hazardous compounds at enterprises is constantly changing, and in the direction of tightening. For example, back in 1968, the MPC of the unsaturated hydrocarbon benzene in the air was 20 mg per m³. At the moment, this figure should not exceed 5 mg/m^3.

What is measured

Harm to the human body directly or indirectly can cause, of course, including hydrocarbons contained in water and soil. But such substances dissolved in the air are especially dangerous. Control over the content of hydrocarbons in the atmosphere of workshops in our country is usually carried out using special equipment - gas analyzers.

Such devices, among other things, can continuously measure the content of harmful compounds in the air. Accordingly, the employees responsible for preventing the excess of the MPC of hydrocarbons can promptly respond to certain identified deviations in relation to the content of hydrocarbons in the atmosphere. Also, modern gas analyzers are capable of:

• record and store monitoring data;
• connect to a common warning and control system.

Types of gas analyzers

Equipment of this type can be used to control the MPC of oil hydrocarbons and other harmful substances:

• stationary;
• portable;
• individual.

Stationary gas analyzers are designed for continuous monitoring of the content of hydrocarbons in the air, for example, in the workshop of an enterprise. Portable equipment of this type is used for single measurements of the concentration of such compounds. Individual gas analyzers are issued to workers to protect them from hydrocarbon poisoning. Such modern devices, among other things, are able to measure not only the percentage of hazardous substances or combustible gases in the air, but also oxygen.

Which gas analyzers should be used for hydrocarbons

For this purpose, at the enterprises of the gas, oil, chemical industry, the standards allow the use of control devices of the following types:

• photoionization;
• with non-dispersive infrared detectors.

Nowadays, special IR detectors are most often used to control the atmospheric air in the workshop. In such devices, the concentration of hydrocarbons is measured by the intensity of absorption of infrared radiation at one wavelength. For example, the content of С₂-С_{10 compounds in air is determined by absorption at a length of 3.4 µm. This is primarily due to the stretching vibrations of the C-H bonds of alkyl groups.}

Identification of hydrocarbons using IR detectors is possible only if the full absorption spectrum in the IR region is measured. Also, such devices cannot provide selective determination of the concentration of aliphatic hydrocarbons С₂-С_{10. Such control at the plant is provided by gas chromatography (separation of mixtures of volatile compounds).}

Ambient air concentrations and how to avoid pollution

Control over the MPC of hydrocarbons in the air of the working area of enterprises should be carried out, therefore, the most thorough. Failure to comply with the standards for the content of such compounds in the air of the workshops will certainly lead to illnesses of the employees of the plant or factory.

However, of course, enterprises working with hydrocarbons must also ensure that these substances do not pollute the environment in any way. Compounds of this type get into the atmosphere, into water and soil most often when they are transported through pipelines. At the same time, losses of such substances as a result of evaporation and leaks can occur both along the entire length of the pipeline and at pumping stations.

For saturated and unsaturated hydrocarbons, MPC in the atmospheric air at the moment in Russia, unfortunately, is not regulated by any federal documents. However, there are hygiene regulations regarding the concentration of some specific compounds of this variety. For example, MPC in the atmosphere is:

• for methane - 50 mg/m3;
• butane - 200 mg/m3;
• pentane - 100/25 mg/m3;
• hexane - 60 mg/m3.

In order to prevent the excess of the maximum allowable concentration in the atmospheric air of saturated and unsaturated hydrocarbons, various kinds of insulating coatings are used when laying pipelines. Most often, enterprises use bituminous mastic for this purpose. Also, companies can apply electrochemical methods of protection of highways. In addition, to prevent pollution of the atmosphere, soil and water, specialists carry out systematic monitoring of the condition of pipelines using leak detectors.

Chemical and oil enterprises themselves can certainly pollute the atmosphere with hydrocarbons. To avoid the release of large quantities of these compounds into the environment, plants in this speci alty often use a modern method of capturing hydrocarbons. At high concentrations (170-250 g/m³) of such compounds, cooling condensation is used for this, at medium concentrations (140-175 g/m³) - absorption, at low (50-140 g/m^{3) - also absorption. In most cases, such simple techniques make it possible to accurately observe the MPCs of hydrocarbons emitted into the environment in the gas and oil industries without any special expenses.}