Halogen/halogenated flame retardants

Antimony and other inorganic flame retardants, Halogenated flame retardants,... 

Addition of approximately 40% of the halogen flame retardants are needed to obtain a reasonable degree of flame retardancy. This usually adversely affects the properties of the plastic. The efficiency of the halogens is enhanced by the addition of inorganic flame retardants, resulting ia the overall reduction of flame-retardant additive package and minimising the adverse effects of the retardants. 

According to the second mechanism the polymer and antimony trioxide form a catalytic complex. The halogen flame retardant then reacts with the complex and expels antimony tribromide. 

There are a relatively small number of producers of halogenated flame retardants, especially for brominated flame retardants, where three producers account for greater than 80% of world production. Table 10 gives estimates of the volumes of brominated and chlorinated flame retardants used worldwide. Volumes of flame retardants consumed in Japan have been summarized (61). Prices of halogenated flame retardants vary from less than 2.00/kg to as high as 13.00/kg. Cost to the user depends on the level of use of the specific flame retardant and other factors such as the use of stabilizers. 

In general, the acute toxicity of halogenated flame retardants is quite low. Tables 11—14 contain acute toxicity information from various manufacturers material safety data sheets (MSDS) for some of the flame retardants and intermediates Hsted in the previous tables. The latest MSDS should always be requested from the suppHer in order to be assured of having up-to-date information about the toxicity of the products as well as recommendations regarding safe handling. 

Fractions containing halogenated flame retardants (e.g., from printed circuit boards, cable insulation, and plastic housings) must be incinerated in suitable plants if recycling is not possible. 

J,W. Hastie and C.L. McBee, "Mechanistic Studies of Halogenated Flame Retardants The Antimony-Halogen Systems,"in Halogenated Fire Suppressants, R.G. 

The next major improvement was the development of combustion modified PU foam. The original CMHR polyurethane foam was developed in the USA (26) and contained hydrated alumina and halogenated flame retardants but was made in a single operation. It was used in institutions, public buildings, hotels etc. but its high density and less than optimum physical properties... 

Flame retardants, 11 447-454, 459-479. See also Fire retardant entries Halogenated flame retardants Phosphorus flame retardants antimony compounds in, 3 54 brominated and chlorinated additive, 11 461-470... 

Halogenated flame retardant production, economic aspects of, 11 479—480 Halogenated hydrocarbon herbicides, 13 329... 

UBA remarked that It is encouraging that there is a general trend to refrain from the use of halogenated flame retardants in products and to replace them with less problematic flame retardants or to redesign flame retardant systems, e.g. by creating greater distances to potential heat sources. ... 

Soderlund, E.J., Dybing, E., Holme, J.A., Hongslo, J.K., Rivedal, E., Saimer, T. Nelson. S.D. (1985) Comparative genotoxicity and nephrotoxicity studies of the two halogenated flame retardants tris(l,3-dichloro-2-propyl)phosphate and tris(2,3-dibromopropyl)phosphate. Acta pharmacol. toxicol.. 56, 20-29... 

Flame Retardants. Bromine compounds make up an important segment of the market for flame retardants used in polymers. Additive flame retardants are added to polymers during processing reactive flame retardants react chemically to become part of the polymer chain itself In addition to the compounds listed in Table 3, a number of proprietary mixtures and phosphorus—bromine-containing flame retardants are also sold (see Flame retardants, HALOGENATED, FLAME RETARDANTS). 

In general, the acute toxicity of halogenated flame retardants is quite low. Continual use of decabu>midiphenyl oxide lias been placed in question based on the discovery that under certain laboratory eondilions brominaled dibenzo-/i-dioxins are generaled. 

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