# Emissions of Volatile Compounds and Solids during Additive Manufacturing by the FFF Method
## 1 Introduction
Figure 2: Schematic comparison of dimensions of particles and the cross-section of a human hair [12]. The research conducted by the authors [12] showed that the printers operated by students in their apartments were located in the bedroom, living room, kitchen, and general purpose room. This indicates that many people are unaware of the harmfulness of the fumes emitted during fused filament fabrication. In recent years, many research teams have addressed the problem of the emission of solids from the FFF process. Tests have also been conducted on the respiratory effects of emitted contaminants [14], and studies have shown a toxic response to particulate matter released from different types of plastics used in 3D printers. Scientists have studied the chemical composition of the particles and their potential toxicity in detail. The FFF process requires that the filament be quickly heated to its melting point in a heating block just before the extruder. After leaving it, the molten plastic is rapidly cooled by the external temperature or by a blast of air. Such violations of the temperature of the material cause numerous physical and chemical changes in the substances contained in the plastic. These changes may include thermal depolymerization of the basic ingredient, oxidation of additives to the material, or the release of plasticizers and non-pyrolytic agents. As a result of these changes, it is possible for both VOCs (volatile organic compounds) and various particles to be emitted. A major threat to humans is the emission of particles in the PM\({}_{10}\), PM\({}_{5}\), and PM\({}_{2.5}\) ranges and below. Diameter is the most important of the many parameters of solid particles. Depending on their values, particles are classified into predetermined types (Figure 3). SPME (solid phase microextraction) is an extraction technique developed in 1990. This technique is particularly useful when the purpose of the analysis is to identify and quantify volatile and intermediate volatile organic compounds, and the matrix is very complex. It is often used to analyze volatile compounds released from various plant materials, environmental samples, foods, insects, etc. SPME is a sample preparation method that is fast, economical, and versatile. The fibers that adsorb the analytes are coated with a polymeric material. SPME consists of adsorbing volatile compounds on a quartz fiber covered with a suitable sorption material (stationary phase). This method has many advantages over conventional extraction methods. The most important advantages of this technique are its simplicity, low cost of analysis, and the possibility of field use, and most importantly, it is not a time-consuming technique and does not require the use of solvents, high sensitivity, small-sized SPME fibers, or sorbing of volatile and medium-volatile analytes. One of the stages of each analytical procedure is extraction, which consists of separating the components of the mixture. Gases, liquids, or solids can be used for extraction. For example, solvent extraction involves the transfer of analytes from a matrix to an immiscible liquid phase. Typically, organic solvents such as methanol, chloroform, hexane, dichloromethane, petroleum ether, or mixtures thereof are used for  
Figure 3: Classifications and sizes of solid particles and their presence in the environment, based on [18; 19; 20]. this type of extraction. One technique that uses solids to isolate analytes is SPME. During extraction, the fiber can be placed directly into the aqueous sample to be tested, and the analytes are transferred directly from the sample matrix to the stationary phase (direct immersion, DI-SPME) or to the headspace above the liquid or solid sample (headspace, HS-SPME). SPME proceeds in two basic stages. The first one is the adsorption of analytes on the surface of the sorbent. The fiber is exposed to the components of the sample, and the compounds present in it are partitioned between the sorbent and the matrix.