Bulgaria
| Country: | Bulgaria |
| Type: | Postage stamps |
| Series: | Environmental Protection |
| Nominal: | 18 ст |
| Year: | 1976 |
| Size: | 43 x 33 mm |
| Perforation: | comb 13 |
| Mintage: | 250,000 |
Environmental Protection
 Poison Cloud damaged Tree 0.07$ |  Toxic Cloud against Sun |