Fireworks and the environment

FFireworks fascinate and entertain many people. A large fireworks show creates an exuberant mood and adds extra glow to any anniversary. A modest family fireworks mark the beginning of a new year. At the same time, one could wonder about what impact fireworks has on the environment. All human activity affects the environment, and there should always be a balance between the positive and negative effects of any given activity. In this paper we’ve gathered facts about the substances that can be found in fireworks, what function they have and what kind of impact they have on the environment. Our motivation is to make it easier to compare the positive and negative effects of fireworks use.

Environmental Studies

Several studies have been done, both in Sweden and in other countries, where measurable fireworks emissions have been studied. In a study from the millennium New Year’s Eve in Stockholm a sharp increase of several substances was observed during and shortly after the launch of large amounts of fireworks. After just one day however, the vast majority of values returned to normal levels.

A government study from 1999 found that the use of fireworks has no significant impact on the environment, with exception of lead emissions, which were considered to have a small but not negligible influence. Since the study was done, a large portion of the lead which then existed in firework articles have been replaced with bismuth oxide, which is considerably more environmentally friendly.

In conclusion it can be said that the emissions caused by today’s fireworks are small but measurable. They fade quickly and pose no significant risk to either people or the environment.

Increased environmental awareness with new products

In order to achieve desirable visual and audial effects fireworks contain a number of different chemicals with widely varying characteristics. In the early days of fireworks, there were pyrotechnic recipes that included arsenic, yellow phosphorus, mercury and many other substances that we today know to be hazardous. Just as with all other industries, the fireworks industry is in a continuous development towards less hazardous and more environmentally friendly products, and the vast majority of chemicals that are currently used in fireworks production are relatively harmless with a strictly limited environmentally impact.

From time to time there have been rumors that fireworks can contain radioactive barium or strontium, thereby contributing to radioactive fallout. Radioactive isotopes have absolutely no applications in the fireworks trade, and have never had.

Any carbon contained in fireworks consist of charcoal, which is a renewable resource and does not contribute to global warming. Fireworks can be said to be climate neutral.

What does firework contain?

The propellant in firework is usually black powder, in pure form or in combination with other substances. Black powder consists of potassium nitrate, charcoal and sulfur. The white smoke formed by firing fireworks consists largely of water vapor. The smoke occurs because combustion of black powder generates large amounts of very small particles that serve as condensation nuclei for any water vapor present in the air. These particles include potassium sulfate and pure sulfur.

To create the different colors associated with fireworks, various metals and metal salts are combusted into corresponding metal oxides. Different metals give different colors. Below is an overview of the function and the environmental impact of a number of commonly occurring firework metals have.

Metals

Of the more than 100 known elements, 80 are metals. Two of the most common elements on earth, iron and aluminum, are metals. Metals therefore occur naturally in great abundance, and many of them have vital functions in living beings.

Some metals are harmful to plants, animals and humans if present in high concentrations. This is particularly true of some of the so called heavy metals. There is no clear definition of what constitutes a heavy metal, but it generally includes metals like cadmium, mercury, lead and more. In general it can be said that these metals are not part of pyrotechnic use. The only exception to this is lead, which may occur in small amounts in certain professional fireworks to induce a specific crackling effect. Except this, heavy metals occur in fireworks only as undesirable impurities in the chemicals used to produce fireworks, just as they can be found as impurities in other chemical products. Emissions from fireworks are still completely dwarfed by emissions from, for example, fertilizer and power plants.

Aluminum (Al)

Aluminum in metallic form is a common ingredient in fireworks. Aluminum is used to make white and silver flashing effects. During combustion it produces aluminum oxide, which is the most common component in typical clay. Aluminum is the third most common element in the earth’s crust and occurs mainly in its oxidized form.

Antimony (Sb)

Antimony is used in pyrotechnics because it burns with a bright flame. Antimony and many of its compounds are in concentrated form toxic or harmful to humans and animals. Antimony is a relatively rare element. The amount of antimony used in fireworks is small and insignificant in comparison to the amounts used in the glass, plastic and textile industries. In the nature, antimony can primarily be found as antimony sulfide in the mineral stibnitt, but it can also occur pure.

Barium (Ba)

Barium is the substance that usually creates the green effects in fireworks. Some barium compounds in concentrated form is toxic or harmful to humans, animals and plants. This is true for barium nitrate, which can sometimes be found in fireworks. During combustion the barium nitrate will react with other substances in the pyrotechnic unit, and will gradually produce more stable compounds such as barium sulfate and carbonate. These are rather insoluble in water and have little effect on the environment. Naturally occurring barium is usually found as barium sulfate, which has a very low level of toxicity for humans and the environment. Barium sulfate is used in large quantities as a contrast agent for X-ray, as a bleaching agent for paper and as pigment in paint.

Lead (Pb)

Certain pyrotechnic units for professional use can be supplemented by small amounts of lead oxides to provide a special crackling effect. Lead oxides, if consumed or inhaled in high concentrations or over long periods, can cause damage to the central nervous system and kidneys, as well as the production of blood and semen. Fetuses and nursing children are particularly vulnerable. Lead also has a tendency to accumulate in the body. Even in the environment lead oxides have negative effects. An intensive effort to phase out lead and lead compounds have been ongoing for the past several decades, both in the fireworks industry and in other areas. Consumer fireworks is now virtually free of lead.

Iron (Fe)

Iron is often added to fireworks to provide sparks. Iron is a very common elemental material, and essential for humans, plants and animals. Iron is for example necessary for blood hemoglobin to be able to carry oxygen. Iron is the fourth most common element in the earth’s crust.

Potassium (K)

Potassium and its salts color flames violet. Potassium is also an ingredient in potassium nitrate, found in black powder. Potassium is the seventh most common element in the earth’s crust and also occurs in large quantities in seawater. Potassium is an essential nutrient for plants and also has several important functions in the human body. The largest application of potassium is in fertilizer.

Magnesium (Mg)

Magnesium is used in metallic form, often combined with aluminum to give white, flashing effects. Magnesium is oxidized during combustion to form magnesium oxide. Magnesium oxide is a harmless substance, used in medicine to neutralize stomach acid and acidic effects from other substances, for example aspirin. Magnesium is the eighth most common element in the earth’s crust.


Retrieved and translated from “Fireworks och miljön - A fact written från Plastic & kemiföretagen”