When building a fiberglass box, it is important to take safety precautions before starting, as well as during the building process. First, make sure safety glasses are worn at all times to protect your eyes. Secondly, wear a respiratory mask over your nose and mouth to ensure you do not breathe in anything damaging. Thirdly, wear thick gloves to protect your hands from being cut by the fiberglass; thin latex gloves will not do the job. Fourth, make sure the area you are working in is well ventilated, as fiberglass releases a toxic chemical. Finally, ensure that you are not working near a gas supply or fire as the fiberglass resin is extremely flammable.